How To Revive Your Imperial's Engine


Imperial Home Page -> Repair -> Engine -> Renewal

Make sure and read our page about valve seal repair which is an important step in reviving any stuck engine.

Tip from Arran:


The first thing to do when trying to revive a stuck engine is to remove the starter motor and then try to bar the motor over. The next thing to try would be to bar the engine over to the right and the left. If it does not move at all in either direction then something connected to the crankshaft is seized, like a piston. If you can turn it partially either way and then it stops, you very likely have a valve train problem such as a jammed push rod or a stuck valve. No matter what it is you are going to have to take the engine apart to investigate and hopefully repair. Basically that means removing the oil pan and cylinder heads whether it's a valve problem or the bottom end. I am still inclined to think that the new starter might have something to do with it since that was the last thing worked on. You have a mystery to solve and you definitely have some detective work ahead of you.

Tip from Dieter:

In 1981, I bought a little '53 Nash which sat for 27 years in my neighbors garage, completely drained of all fluids including the brake system.  The prior owner even removed the spark plugs in fear they also would would rust and marry the block.  Instead of pouring oil through the intake - carburetor, I used the empty spark plug holes. A product named Mystery Oil did the trick for me on that engine.  I 'm not saying it was easy;  it took a couple of evenings after work and a 24" breaker bar laying across 2 small protruding pieces of steel on the crankshaft pulley.  I had the car literately rocking and rolling until I realized she was in gear. The car was far from having a battery installed.   I did finally succeeded of freeing the pistons and did all the necessary items to get her started. After many tries she finally sputtered to life shaking coughing and, of course, smoking like heck.  My back yard neighbor, not knowing what I was working on my buggy, called the fire department, thinking my garage was going up in flames  My advise- poor  oil through spark plug holes.     

Tip from Rolland:

Sometimes a long storage will result in stuck rings or damaged cylinder walls due to corrosion. Many times this will correct itself with some highway driving. After it has warmed up try running it for a distance (maybe 30 to 50 miles) to see if it improves. It will take longer than that to totally free up but you will get an indication. During this time it is not necessary to run at high speed but go to wide open throttle from say 30 mph to 60 mph without letting the transmission kick down. This will load the rings and help free them as well as let the cylinder walls clean up. Some oil additive such as Rislone in the oil may also help. If you don't see some improvement after 300 to 500 miles you may be in for a rebuild.

Reminder from Bill:

Rislone is not good for an old engine unless you are willing to drop the pan and clean it out after use.  Rislone does an excellent job of cleaning, sometimes too good.   I lost the engine in my Plymouth because I used it and did not clean the pan out afterwards.

Question from Charles:

I have an engine that is stuck with rust. I have read here before that vinegar with dissolve rust, fill the engine with vinegar for a few days? How about some of these wonder chemical that eat rust and nothing else, are safe to drink, are packed with vitamins, and double as after save lotion. After the rust fill the engine with wd-40 to remove water drain and refill with Cod fish oil... I do not have much to lose here, toss me some ideas...


From Mark:

I had a Caddy that was in storage for 25 years. I didn't take a chance turning the motor over and just assumed it would be stuck. So, I may have been lucky with the following advice. But, you certainly can't lose from where you're currently at!

I bought a gallon of Marvel Mystery Oil. Removed the plugs and filled each of the cylinders up. I let that soak in overnight and repeated this for a week. That weekend, I took a pipe wrench and turned the crank barely half a cylinder stroke. and repeated the cylinder soak and let it sit overnight. I repeated the pipe wrench and soaking steps nightly until I had moved each of the cylinders a full stroke up and down.

I got brave and applied power to the starter with the oil in the cylinders and (after rebuilding the carb, fuel pump, water pump, new radiator, etc) started the car up on a separate gas can (didn't trust the tank). Didn't break any rings and everything seemed well sealed.

From Arran:

The first question that I would ask is whether the engine is still in the car or has it been pulled out? If it is still in the car pull it out so you can dismantle it easier. If you can remove the crankshaft from the engine, and undo the con rod bolts, do so. Cover the ends of the con rod bolts with chunks of rubber hose so you don't nick anything. Oh, you need to drain the block of coolent as well.
The vinegar trick basically works like this, you fill each stuck cylinder, from the top, with vinegar. You heat it for an hour or so with a big soldering iron, or BBQ starter, until the rust starts to disolve. You then try to move the piston by pounding on it through a block of wood, I used an appropriate sized round of firewood. If it doesn't move, fill the cylinder with vinegar again and heat it some more. If you can remove the crankshaft it makes it a lot easier to pound the pistons out. Someone told me that machine shops have some kind of dip tank that will loosten a rust stuck engine but you will have to check into this. I suspect that CLR might dop the same job without the heat but I figure hot vinegar is a little less risky for damage since it's weaker. However glacial acetic acid, used in photography, may be a viable alternative to vinegar.

If your engine is seriously seized by rust, diesel will not work whether you soak it for a week, or six months like I did. The point
being that the method that I have used is not hearsay or,"Some old farmer's trick", I have actually done so myself. I have heard of the brake fluid approach but I can't see how either glycol or silicone would work to disolve rust, although the silicone might make a good lubricant. If the engine is lightly seized, yes you could turn it over with a breaker bar on the harmonic balancer pulley, but with no more then a three foot bar. If you try to use a longer bar, and the engine doesn't free itself, there is a good possibility that you will break the harmonic balancer bolt. From what you describe it sounds like you will need to take the engine apart, at least partially, if it sat that way for any length of time. I have tried every trick that I heard of but none of the people that recommended them had ever tried it themselves. Unseizing an engine is a tough job, even tougher on a V8, and most of the shortcuts are worth what you pay for them, nothing.

From Ted:

I have had a of success with ordinary transmission fluid added to all cylinders, and allowed to sit for several days. It is thin, and penetrates well. When the rings come loose and you start the engine, the residue will quickly burn off. Be sure and remove as much of the fluid as possible before starting the engine so it doesn't fluid lock up.

From Paul:

I also have had good luck with transmission fluid (Dextron II) to free a stuck engine. The car had been sitting for 35 years without turning over. I filled the cylinders through the spark plug holes and also filled the crank case. I let it sit for 10 days and then was able to get it to move. Gradually the engine was able to run, but it had been in very good shape when it was parked. The inside of the engine was not visibly rusty looking.

If an engine has locked up due to water in the crankcase (rust), or overheating it is not likely to ever turn again unless it is disassembled, machined, and rebuilt. If it does run, these conditions will have sufficiently damaged enough parts that it would not run very well, or for very long.

From George:

If you are trying to bust a long shut down motor put 1/2 Transmision fluid & 1/2 Diesil oil in each cylinder for a week through the spark plug holes. Use a pimp oil can then try to break the cylinders loose using a big socket on the damper pully rocking back & forth till it is free. Then you can rebuild the motor.

From Roger:

Pull the plugs, squirt brake fluid in the cylinders put the plugs in and let it set for a week. The brake fluid will break up any rust in the cylinder. Pull the plugs and work it with a breaker bar. It is an old farmer trick and it works. I have done it on old tractors that the exhaust was open on. Frees them up and they usually fine when your done. That is if the valves are not stuck. If it is a flat head it works on the valves too.

The acidic action of the brake fluid will remove paint, rust, gasket material, carbon and un-seize frozen parts. I have used it on two flat head ford V-8s, a Studebaker flat head six and a ford 312 Y block. The Y block had to have the right head removed due to a stuck valve. Each engine would run afterwards. Of course it will work only on engines that have not been setting open for years or filled with rain water many times. My flats were in pickups that had set out with the air cleaner off but the hoods down. One was in a old building and ran well when put in. The y- block was upside down under a tarp with no carb on it. It was a free bee.

Here is another tip that works and if you don't believe try it yourself. WD-40 will clean stainless and other metals, your hands after working on these metals, and can be used for fishing.

Question from Patrick (392):

I'm just getting started on a '58 Southampton, my first attempt at a "restoration." The Hemi's been sitting for 27 years and I'm accumulating lots of great advice from Dick and Hugh about getting it back into service. I read Ross's article too. I plan to drop the pan, clean out as much gook as I can, clean the oil pump, pull and clean out the valve covers, etc. I'll also wash out what I can from the collant chambers. I'm not going deeper until I determine that the motor will fire. A european mechanic friend of mine warned me to make my initial work investment by confirming that the motor would fire. He said (add Swiss accent here): "You moost make soore there's a strong heart before you eenvest in the boody." Sounds like mail-order bride advice.

Question: One local motorhead has advised me to fill the drained block with diesel fuel and hand-circulate it to clean out the crud. I'm not entirely sure I want to risk that, especially if I see an accumulation of baked-on goo that may be best left "asleep" until a rebuild. I suspect, however, that the block is clear because there are dozens of oil change stickers stuck up and down the driver's door frame and even a few under the hood. (what was that all about, I have to wonder?)

Regardless, any thoughts out there about the diesel method of block cleaning when you're trying to get a dead but not caked engine just clean enough to fire?


From Kate:

I come from a long line of old time mechanics, and adding a pint or 2 of diesel to engine oil has long been accepted practice to clean out an engine that's possible been doing without decent oil changing intervals. You were not to run the engine hard on this mix, just warm it up andlet it run enough to exercise it, then dump it out. I have personal knowledge of a man who ran his Pontiac over 100.000 miles without any work whatsoever; he would put a pint of diesel in it and let it idle for some time, just before dumping the oil for each oil change. The mechanic who bought the car took it down for a routine overhaul (his practice on all high mileage cars) and stated he had never seen an engine as clean or free from abnormal wear. I have also heard of people doing the same routine using transmission fluid.

one other point - I had the fuel pump cough up a chunk of diaphragm rubber which lodged in the brand new carburetor on my (REALLY USED) engine in a Datsun B-210. After the obligatory few tries at restart it was towed home, where I pulled apart the carb, cleaned out debris and resealed, and installed another filter in line! In putting the carb back on I saw a glimmer in the intake manifold - it was gasoline.......... doggone engine chuck full of oily gas.... and I had been cranking it trying to get it to fire! shudder........AFTER dumping over 2-1/2 gallons out of the crankcase, I refilled with appropriate oil and a new filter and started up without incident. The tired engine never ran better; compression improvement across the board, no doubt due to freed-up rings. Upon replacement of that engine a couple years later, I tore it down to take a look - that unintentional solvent bath sure made for clean innards! and there was no evidence of scored cylinders.

From Hugh:

I see no reason for the diesel oil. Be sure NOT to use oil with detergent in this engine. The advice I was given is counter to what you have heard. If there is crud in the crevices, just let it stay there. It accumulated there for a reason and beating yourself up to remove it is a fool's errand. When I restarted mine, the plugs were removed, we put in a wee bit of marvel into each cylinder and let it set a week. We filled the radiator, put in a fresh battery and cranked it over using the starter motor, without the plugs in. It turned over just lovely. We put in the plugs and it roared into life just lovely! Filled the room with smoke, though, and left an indelible mark on the wall behind it but it ran nice. We got, after I had to fix the water pump, ten years of great service from it until a water pipe from the radiator burst and I ended up cracking a head.

In retrospect, we should have changed the oil and flushed the coolant channels first. But, you know, the engine is going to be dry as a bone at the top regardless of what you do, until the pump can get oil up there which will take a few more agonizing seconds than you'd like. We all have our own tolerance for risk. I didn't know I was going to become so heavily involved with my 58 at the time. To me it was just another piece of junk with a paint job at the time.

I cannot say if your engine is stuck, and neither can you. There is no reason to assume it is stuck. The oil you have seen on the dip stick did not indicate the presence of water. I'd drain the oil and wash out the coolant pipes as best I could. Be sure to drain the oil pretty quickly after you have let it warm up. As the engine warms up, the circulating oil will remove what needs to come out. You must change the oil often during your initial period of using the engine. I'd do several additional coolant flushes as well. It is from these channels you will get the must rust and gunk. Have you found out how much fun it is to change an oil filter on this thing yet? I hope you have skinny fore arms!

From Rob:

The diesel oil serves the same basic purpose as the Marvel Mystery oil. Whether you want to clean the engine out by soaking it in diesel or marvel mystery oil is subject to debate. Without a doubt it is a good idea to drop the pan, change the oil and clean the oil pump pickup screen.

Turning the car over with the plugs out is a good idea. A better idea is to prime the car using a drill and one of those tools that fit in the distributor drive.

From Paul:

That is a great story Hugh.

I'll add that determining if the engine is stuck or not is about as easy as rolling up your sleeves. I think that would be about the first thing to find out before proceeding with anything else.

Also, if you don't at least drop and clean out the oil pan, and clean the oil screen before starting the car you are asking for trouble. I suppose that one could say that "all that crud is there for a reason". As far as I know that reason is neglect. It was never intended to sit there for 27 years.

There is truth to the fact that during the time when non-detergent oil was common, engine sludge would accumulate in the oil pan. The oil pan is designed to handle this, but it also is suppose to be cleaned out periodically. Once cleaned out, there isn't any reason why detergent oil couldn't be used, although I would change it very frequently especially during the first several hundred miles.

I wouldn't put anything in the crankcase until the pan has been cleaned out. If the sludge (that is probably there) becomes free, it could be pulled into the oil passages and result in serious lubrication problems.

From William:

I've heard the same things about diesel in engine oil and also in the gas tank to decarbon on long trips. I've also read the deal about "no detergent motor oil" too. Then there was the old "ATF and water in a Coke bottle" trick to decarbon too, but that required some experience to do correctly.

Diesel, just as is ATF, is a thinner oil that does have some detergent characteristics AND will get into places to restore oil flow that normal motor oil might not. It penetrates and then opens things back up with time. Plus keeping all of the oil soluable gunk in suspension as a good detergent motor oil will do too. If the gunk has big enough particles, the filter should catch them too.

As for the "no detergent motor oil", the detergent in motor oils is designed more to clean "as it happens" rather than do a specific quick clean up from existing deposits. There are any number of additives which will clean the inside of an engine that has gotten gunked up from lack of maintenance or just prior to overhaul. In some cases, the more HD cleaners will have you add them to the oil and then run the engine at fast idle for at least 30 minutes before changing the oil. Whether or not you do that with the existing dirty oil or put a new oil and filter in first might be a judgment call the owner made.

When I bought my '70 Monaco Brougham 383 4bbl, when I looked inside the valve cover through the oil cap hole, I noticed some buildup on the rocker shaft. I found some Stewart-Alemite CD2 Oil Detergent additive. I did an oil change and when it got 1 quart low, I put a 1 pint can of the additive in instead of additional oil. When it got back to the "Add" line, I added another pint. By that time, the rocker shaft was pretty clean. I did an oil change and the oil stayed cleaner longer.

One other thing I usually do when I do an oil change is that after the oil is still dripping out of the drain plug hole, I'll pour an extra quart through the oil filler cap hole in the valve cover. Basically, this makes sure that most of the residual oil in the pan is flushed out as soon only new oil, with a thin line of dark oil, is running into the drain pan. Not sure if it works or not, but with the price of non-synthetic oil (even back then), it's a cheap deal to do.

There was also a CD2 additive that was similar to STP, or a viscosity improver, but what I was using was the detergent additive. It caused no problems and did get things cleaned up too. I'd rather trust a name brand than something else for things like that.

ALSO, as everyone has been concerned with oil in the engine, if the engine's been dormant for an extended period of time, it might be a good idea to pull the valve covers and pour oil and some extreme pressure oil additive down over the rocker shaft and also down the push rod holes in the head. It's one thing to make sure the bottom end's taken care of, but that upper end stuff needs oil quickly too (the only oiliing the lifter and cam lobes get is from oil thrown off by the crankshaft, for example). After doing that, then remove the distributor and distributor drive gear so you can turn the oil pump with an adapter and a drill motor. This will get all of the internal oil passages lubed up prior to start-up too, but probably not affect the cam/lifter area that much (other than the cam bearings).

As for an "in chassis clean out", you would need to remove the oil pan, the valve covers, and intake manifold and related items so that you had unrestricted access to the lifter valley and upper end of the motor. Then, one you could use the diesel fuel to flush things out and probably then wash everything down with Varsol (or similar) before putting everything back together with a fresh oil and filter change. That should get everything out of the heads, lifter valley, internal block surfaces, and the oil pan. Messy? Yep! Effective? Pretty much. But it would not address the combustion chamber deposits and such, which can then be done and a final oil/filter change too.

As for fuel additives, it has been mentioned that some fuel cleaner additives can thicken the engine oil. I read this regarding Techron. They are designed to be used one bottle at a time, basically. It was noted that using Techron "double dosed" or one bottle with each of two consequtive fill-ups can thicken the engine oil, so some caution might be in order there.

In any case, resurrecting a dormant engine can be rewarding AND somewhat labor intensive AND not always done very quickly. Of course, probably the best thing to do would be to pull it out and take the whole thing to a competent and reputable machine shop (usually NOT a mass rebuilder!) who might have an appreciation of and expertise with Chrysler engines.

Follow-up from Paul:

In addition to the points that have already been made about the oil pan and oil screen, I really like your idea and willingness to clean out the inside of the valve covers and the rocker trains.

One problem that I have seen in old dirty engines is that the oil drain holes can plug up, and as the engine runs, the oil builds up in the top end, starving the rest of the engine for oil. A lot of oil can accumulate in those giant Hemi valve covers. Eventually, the oil seeps down through the valve guides fouling out the spark plugs, or pushes out through the valve cover gaskets to burn and smoke on the exhaust manifolds.

The cylinder head drain holes can be rodded out very easily with a wire, or even a straightened out coat hanger. Examining the amount of crud built up in the top end will tell you a lot about the kind of maintenance the car may have had before it was parked. Even in 45,000 miles there could be a lot of build up there if the car wasn't properly maintained.

Question from Rick (413):

How do you turn a stuck engine? I checked the repair portion of the web site but nothing actually tells you how you turn a 413 that doesn't want to turn. It's still in the car and I shot oil cylinder. On a slightly different subject I popped a couple of the freeze plugs and it's incredible how much gunk is in there. I would recommend anyone who has a over heating problem might look there.


From Dave:

Remove the spark plugs first, that way you won't be working against cylinder compression. Then use a 1/2" drive ratchet or breaker bar on the bolt holding the crank shaft balancer on, making sure the battery is disconnected of course and the transmission is in neutral. You could also try turning it over using a flywheel wrench to turn it over. If it still won't turn over you have a bigger problem that you thought. By the way how long has it been sitting and what caused it to seize?

From Neil:

If the engine is that tight I would recommend stripping it and find out why, If you do get the engine to turn you will be tempted to try and fire it up which will cause a lot of damage to all the crank bearings and cylinder bores.

At the very least drop the oil pan down and have a look at the mains/big end bearings, if they look bad you will have to strip the engine down.

From Rob:

Pull the plugs first. Some people swear by soaking the cylinders in Marvel Mystery Oil, then the breaker bar with plugs out method, but knock-wood, none of my motors is frozen.

Question from Tim (413):

After pulling the plugs, oiling the cylinder walls, and a 4-ft breaker bar on the crank bolt she won't turn. What's next? Should I just start tearing it down or is there other methods to this madness?


From Chris:

Oh, how familiar that problem is. Well, there are two ways you can go, depending on how much time you want to spend. Sometimes, filling the cylinders with diesel fuel or penetrating oil and walking away for several weeks may free it, but some rings could still be stuck. My experienced suggestion is to pull the motor and CAREFULLY take it apart, keeping track of where everything goes, and IF you can get the individual pistons out without damaging the pistons....AND if the pistons aren't corroded, all you need is a re-ring kit (very inexpensive). With that, you get new rings, new rod and main bearings, and usually all the seals and gaskets. Also, you'll have to de-ridge the top of the cylinder walls. This re-ringing is equivalent to rebuilding the motor at a small fraction of a full rebuild.

From Steve:

Load each cylinder with penetrating oil and trans. mission oil. A good battery and just pulse the starter. Go with the bar and the pulsing. I have freed quit a few in this manner. After you free it change the oil before attempting to start it.

From John:

I've used Marvel Mystery oil in the cylinders, then used a breaker bar to try to turn before trying the starter & have had good luck.

From Paul:

I think that you can drop the pan on a 1960 without too much trouble. You may have to disconnect the steering linkage from the frame. It might be a good idea to do that, and check the inside of the motor from down below.

Once opened, you will know if there is any point in continuing trying to turn it over. If everything looks greasy, that is a good sign. Clean the pan and the oil pick up screen and keep trying.

If everything is rusty looking or corroded, then you are wasting your time. In that case, the motor would need to be pulled and re-machined. Even if you could make it run it wouldn't last long.

Question from Mike (1970 with a 440): 

My car has 101,250 miles on it and has been parked inside for 18 years... Any suggestions on what I need to do to get this thing running?  When I looked at it yesterday it seemed to have clear clean oil in the engine...


From Dick:

It is very important to not be fooled by the clean looking oil. If the engine has not been started in years, the oil will always look perfectly clean, this is because all the particulate matter has settled out. Before you turn the key for the first time, you must drain the oil and take the oil filter off, then put the drain plug back in and pour a can of Rislone or better yet, Alemite CD-2 oil additive into the oil fill hole.. Nothing else, just one can of this powerful detergent additive. Then, still without trying to turn the engine over, rock the car as hard as you can, maybe letting the tires down a bit so they are softer, so you can get the additive to slosh around in the bottom of the oil pan. Do this for a while, then let it sit for a while, then repeat, as many times as you have patience for, then finally drain out the additive, and leave the plug out at least overnight, so as much of the abrasive crud comes out, drip by drip, as will come. (In really old cars, I recommend dropping the pan and scraping the gunk out by hand, but I assume you are not up for that.) Then finally refill with new oil, put a new oil filter on it (prefilling it with oil first, if you can do that, so you have oil pressure as soon as you crank it, rather than waiting for the filter to fill), and crank it very briefly, a few times, a few seconds at a time with maybe a minute between tries, so that you are beginning to have some lubrication on the moving parts before you add the pressure of combustion to the bearings and pistons. 

Once you have gone through all this, you can follow your nose as to what to do next, you will not be as much in danger of causing damage by running a dry engine or pumping crud through the oil system. 

If you don't get a spark, and this car has points and condenser ignition system, very likely the points will have a film of oxide on them from sitting, the film can be removed with a point file, but it probably makes sense to just replace the points and condenser, they're cheap and easy. If it has the electronic distributor ( I think 69 or 70 was the changeover year), you don't have to worry about the points, of course. 

As to getting gas to the carburetor, just to see if that's your only problem, you can safely dribble a few ounces of fuel into the bowl vents that come out the top of the carburetor, this will fill the float bowls and allow the engine to run even if the fuel pump/lines/filter/tank system is not working. Replace the air cleaner after you put the gas in the carburetor, to prevent a flashback of fire in case an intake valve is stuck open. If it does start for a second and then dies, you can add more gas to the carburetor by trickling it down the center screw under the wingnut on the air cleaner, with out removing the air cleaner. 

If you do experience a flashback through the carburetor, keep cranking to suck the flames back into the engine. It won't hurt the engine, but flames will sure mess up your hood (and your eyebrows!).

From Peter:

Your car will have point-style ignition, so you may experience the "no spark" condition.  69, 70, and 71 Imperials all had point style ignition systems. Since new technology usually hits high end models first and I know that some Chrysler A-bodies first had electronic ignition for 72, it's probable that all 72 Imps had it. 1973 was the year that ALL Chryslers had electronic ignition systems. 70 Imps do have an electronic voltage regulator, which may have been the first year. (BTW, 1970 was also the year that the ignition switch moved from the dash to the steering column. My car had the sheet of plastic that slipped over a sunvisor explaining the new feature to owners.) I strongly recommend installing a carburetor kit before you try to start the beast. 1970 was the last year for the Holley 4160 carburetor (R-4366) and it has float bowl at both the front and rear ends. I guarantee you that the float bowl gaskets have dried out and shrunk. When fuel flows into the bowls it will immediately leak onto the top of the engine (which is, of course, very bad news). Buy a Holley kit, not any other brand! They're under $30 and there IS a difference. I speak from experience on this issue. Another potential pitfall is the heat riser valve on the RH exhaust manifold. Make sure that it isn't frozen in the closed position. If it is, most or all exhaust gases will be forced to flow upward and through the base of the intake manifold. This is the way it is supposed to work during warm-up, but driven long term that way the excessive heat is likely to warp the carburetor (and cause drivability problems). Once you're running, you should go over the brakes thoroughly before joy riding. Finding a limp brake pedal on a moving car over 19' long, 6' wide and 2 1/2 tons is a VERY bad feeling. 

From Jack:

Just spray some WD-40 in the cylinders and let soak for at least a day, then turn the engine over by hand using a breaker bar and socket on the front of the crankshaft. You will be doing this to avoid breaking any piston rings that may be tight in the cylinders, so be careful. Also check the condition of the inside of the fuel tank. before filling it up with fresh gas. Loose rust can really clog things up. (I know from experience)

Question from Pete:

My engine will turn but won't fire.  Any ideas how to get it to fire?


From Ross:

My better luck on getting unused (not correctly stored) motors has been to include pulling the oil pan, cleaning it and the pickup. Plus, filling with a cheap 30W and a quart of kerosene and turning the oil pump from the distributor drive with an adaptor and electric drill . . all to help clean out the passages . . and monitoring an adapted remote oil gauge. If this is all old news, just forget it. I also like to convert all motors over to fully synthetic (believe there to be no substitute, especially after the FAA issued an AD [Airworthiness Directive] for air-cooled piston airplane engines a few years back); and though I usually have to replace a few gaskets on covers, find that it'll get some of the "crud" out of engines that have been sitting around too long. I realize that some will disagree with me . . I just change out the synthetic at 2000 miles first time and use only HARD DRIVER or MOBIL ONE filters with fully synthetic filtering media. Bingo, no oil system problems afterwards.

From Mark:

Yep, the pump can be removed with the engine in the car without too much difficulty. ESPECIALLY in an Imperial. The external oil pump is one of the more elegant design aspects of the big-block MoPars. (And is shared with all the MoPar in-line sixes and eights.) And, like Peter wrote, that shaft is not going to come out, unless you remove the distributor and pull it out from the top.

Tips and Question from Jay (1962 with a 413):

I have more news from the sleeping giant (our '62 Crown 4-door.) Hopefully my experiences on starting this beast will benefit others embarking on similar quests. 

We checked and topped all the fluids, changed the oil, inspected and gapped the spark plugs and shot WD-40 into the cylinders via the spark plug holes. Last night I visited the '62 again, with the ultimate goal of starting the engine. I purchased 8 gallons of aviation fuel (100 octane, low lead) at the airport and I siphoned it into the tank of the sleeping giant. I checked the fluids again, connected the battery and disconnected the coil wire. My intention was to crank the engine over several times to get the oil up in the galleries and lubricate the entire engine before I actually started it. When I connected the battery, I noticed a faint buzzing sound coming from somewhere around the brake booster/firewall. I traced the buzzing down to the clock. The sweep second hand was vibrating! I removed the appropriate fuse to disable the clock circuit. I disconnected the fuel line "downstream" from the fuel pump and attached my siphon hose there. This was done so that I could use the fuel pump to purge the fuel system of any old gas. I used intermittent cranking of 10 to 15 seconds for a total of 2 minutes. Everything sounded good as the engine was turned with the starter. I checked the fuel line to see if it was pumping gas yet - It wasn't.  I plugged the fuel line with my finger while I cranked the engine, but I felt no pressure in the line. I figured that the fuel system was bone-dry, and the fuel pump needed priming. I cut a 1 1/2 >foot length off of my siphon hose and attached it to the fuel line at the top of the engine. I tried pouring some fuel into the line in hopes that it would trickle back down into the fuel pump - it didn't. I though about it and figured that, with the back of the car sagging due to aged springs, 8 gallons was not enough gas to get the fuel level up higher off the ground than the fuel pump was. I made a quick trip to the gas station to get another 14 gallons. 

Back at the car, I added the 14 gallons to the tank. When I cranked the engine, the fuel that I had previously poured backward into the fuel line shot straight up out of the line! With the fuel pump primed, I added a new fuel filter and reconnected the line to the carburetor. I reconnected the coil wire. I was now for an attempt to start the engine. 

I used jumper cables to connect in parallel the battery of our '66 Crown to the battery of the '62 Crown. I poured some fuel into the primary barrels and, with the ignition on, tried the starter. The engine started, only to die a few seconds later.  I primed the carburetor again for another try. As it fired and ran for a few seconds, I noticed that the oil pressure was coming up and the Alternator gauge moved too. The Gasoline gauge showed no signs of life even though I was very close to a full tank of gas. The throttle linkage and choke butterfly mechanism were very sticky, so I shot the moving parts with some WD-40 and they feed right up. The accelerator pump doesn't seem to function as no fuel "mist" was observed when the throttle was pumped. At one point I was able to get the engine to run for about 30 seconds and even though it cold, it sounded great! It ran smooth and didn't miss at all until it was ready to die of fuel starvation. After another hour of trying to spoon feed the engine back to life, I was ready to call it quits for the evening. Things are looking good - the engine wants to run and sounds healthy when it tries. I have pulled the carburetor off and will either rebuild or replace it. I could have a problem with the fuel pump too, but I will look into that further if the engine won't run after the carburetor is taken care of.   


From Dick:

You need to determine which problems are related to the carburetor and which are due to the fuel pump system. Try the following steps, before you take anything apart: 

1. Unscrew the 1/2" flare nut that holds the gas line from the fuel pump OUTLET to the carburetor, and arrange a temporary fuel line so that you can blow directly into the carburetor. (An easy way is to push a 3' piece of fuel hose over the fuel pump end of this line.) Try to blow into the carburetor. It should be easy, since the float chambers are empty, and the needle valves are open to admit gas. If it feels like you are blowing into a solid wall, you will need to remove the carburetor to a clean work station for investigation. For sure, the needle valves are stuck, and probably the accelerator pump leather has shrunk away from its well walls. You can fix either or both of these problems without doing a complete carburetor rebuild, but the chances are if you are having these problems, there will be others with the carburetor also. If you are able to blow into the carburetor, it's time to investigate the fuel pump further, since if the carburetor can accept fuel, the car should have kept running, even if the carburetor has a few problems. (Its beside the point, but here seems to be a good place to mention that I have had very bad results with "professional rebuilds" of carburetors. Any boob can buy the kit and do a GOOD job on his own kitchen table with spray carburetor cleaner, patience, good light, an understanding wife, and the ability to read the King's English. Why the commercial rebuilding shops are unable to turn out a good job I do not know, but it's a fact!) 

2. Assuming the carburetor is ready to accept fuel, the next step is to pull the gas line from the fuel pump INLET, remove the fuel filler cap, and blow back toward the tank, using a clean piece of fuel line so you don't have to inhale gas fumes. (This will be a next step if you determine that the fuel pump is not feeding the carburetor with gas, even though you are sure there is gas in the tank.) You should with sustained normal lung push (for 10 seconds or so) be able to hear a vigorous bubbling inside the tank if the pickup tube and lines are clear. If you seem to be blowing against a solid wall, you will have to drain the tank and clean it out. When the tanks sits with gas in it, the old gas tends to congeal and plug the "sock" that separates bad stuff from the gas at the tank pickup point. The same gunk often glues the tank sender float to the bottom of the tank, thus preventing the guage from registering anything other than MT until it is freed up. It is possible that a shop air hose applied to the fuel pump end of the gas line to the tank would punch through any accumulated guck, but you would have recurrent problems unless you cleaned out the tank anyway. (Do not try to push gas through from the tank end of the line, the tank cannot tolerate any more than a few PSI of pressure.) 

3. If all of the above does not clear up the problem, verify that the fuel pump is putting out at least 3# of pressure at the outlet (beg, borrow or steal a combination vacuum/pressure gauge, they only cost a few bucks and you'll use it all the time). It also should pump about a quart of gas in 2 minutes or so (+ or - a bunch) when the engine is idling. You can get the engine to idle by filling a squirt oiler with gas and pumping it into the air vents on top of the carburetor's float chambers. Fill the float chambers and the car should idle for a few minutes, even if everything else is screwed up. Tell me what kid of Carburetor your car has (probably an AFB?) and I'll tell you how to identify the float vents, if you can't figure it out. I see I never mentioned the fuel filter. If it's still the original MOPAR filter, visit the NAPA store with the old one in tow and they will match it pretty darn close. If you want to try to use the old one, just blow through it in the direction of the carburetor, there should be no noticeable resistance. If there is, don't waste your time fiddling with it or trying to back flush it - I'm the cheapest guy I know, and even I don't bother trying to resurrect a dirt gas filter.

From Nancy:

If a car has sat for a long time without running you should probably replace the fuel pump even if the car runs with it. The fuel pump can leak into the engine putting gasoline into your engine oil. This does not do your engine much good and may go one for some time before you notice it. Rather than risk the bottom end of your engine, gasoline is a very poor lubricant, you would be better off replacing the fuel pump on cars that have been sleeping for many years. Fuel pumps are cheap compared to having your engine rebuilt. They are also readily available for a 413, easy to install and you can check on the condition of your timing chain while you're in there.

Question from Paul (1972 with a 440):

I own an Imperial that's been stored (and not driven) in a garage for at  least the last 8-10 years. Please offer any and all suggestions on what I  need to do and what I should do.


From Paul R.:

DON'T TRY TO START IT ON ANY OLD GAS THAT MAY BE IN THE TANK. If you are very lucky, the tank is dry in which case you might be OK to add fuel. Most likely you will need to pull the tank, have it cleaned out and coated and you will probably find that the fuel pump has failed too from the old gas that was trapped there. Blow out the fuel line too. If you don't pull the carburetor, watch carefully when you do try to start it that you don't have fuel spilling out because the floats have stuck. Engine fires are not fun. I think it is also a good idea to pull the spark plugs and lubricate the cylinders with a couple of squirts of motor oil down each spark plug hole and then turn the engine over a few turns before you replace the plugs. The transmission will probably be 2 to 3 quarts low from leakage while sitting so add Dexron fluid before you drive it. Check it while the engine idles and the gear selector is in neutral...(NOT PARK). Don't trust the brakes even if they seem to work by just adding fluid. Regular brake fluid absorbs moisture from the air and you probably have rust formations inside of you brake cylinders. Take them apart and inspect/repair before you drive it very much. The above suggestions come from numerous experiences in reviving old MoPars after varying lengths of storage time.  

From Kne:

1. Rebuild Carburetor. 

2. Change oil. 

3. Make sure engine is not frozen. (be nice to starter) It would be nice to spray some WD-40 in the spark plug holes, but I know some are hard to get at with the stock exhaust manifolds. 

So...maybe have someone stand by when she first starts, and spray some bursts of WD-40 in as she starts to lube the top end and upper cylinder walls. They are probably quite dry and if there is some slight surface rust on the cylinder walls the rings would appreciate a little help I am sure. Spraying it into the intake charge should also give a bit of lube to the lower half of the valve guides. Be sure your helper keeps their face away from the carburetor as she may wheeze and pop a bit, and your helper won't want eyebrows and nose hairs burnt off I bet. Very disorienting when a huge fire-ball engulfs one's head. Anyhow go from side to side on the carb spraying half second bursts, don't totally hose it to where it is stalling out. 

4. It would be nice if you could also remove the valve covers and pour some oil directly on the rocker arms and valve springs. Be generous and that oil will also drip down on the lifters and cam. 

5. Then I would change the oil again after about 500 miles.

This page last updated June 14, 2004.  Send us your feedback, and come join the Imperial Mailing List - Online Car Club