Diagnosis and Repair of Your Imperial's Camshaft, Lifters and Tappets


Imperial Home Page -> Repair -> Engine -> Camshafts

Tips from Mikey:

Can I really replace my cam bearings in my car? Yes it CAN be done! There is actually a use for those ( IMHO ) worthless rubber core plugs that you buy to get you home if you lose a core plug and you're desperate. These plugs are generally in nominal sizes and have a fair amount of expansion range when you tighten the little nut in the center of them.

Several times, we have used these plugs to remove and replace cam bearings when there was no option of removing the entire engine...you need a suitable size plug which is the easy part, and a driver to mate with the plug so you have a suitable surface to pound against. We have found that a piece of steel rod , preferably hollow so that it will fit over the plug expansion nut , will make a very suitable tool . The installation is just as easy, the trick here is to use an indelible marker and make matching marks on the block before you start to ensure the oil holes - if applicable - are indexed with the holes in the block.

Why you may be asking, did we go to all this trouble.....ever see the inside of a Detroit diesel or a Cummins inline? It is sometimes easier to remove a radiator and stack up a few lengths of steel rod than remove a 2 ton engine block ! This same trick works well on passenger cars too....the radiator is usually in the way, and sometimes you have to tilt the block a bit to get a straight shot at everything. Thankfully a big block Mopar has a very open valley and room to get fingers and such in there to work after the intake is removed. The caveat here is, the pan is removed and you're doing some kind of repair or overhaul. I'm sure you could do this with the pan on.....better hope you don't drop one!

Of course, since most engines have cam bearings diameters that change from bearing to bearing, you have to do the installation with the smallest one first and so on and so on....and obviously, you do this AFTER you hone anything unless you have a grit fetish and want to watch your efforts go to waste in a hurry. Remember...it can never be too clean.

Question from Kerry:

One question I'm not following though. I understand how the plug expands to grip the bearing and I understand how you can drive the front bearings backward and out. How would you get out the rear bearing? Drive it and the plug out the back of the block?

Reply from Mikey:

For Kerry, who caught that point that I had failed to mention, since this particular bit job is one that is hopefully not done so often, on the rear bearing we had a couple options. One was to use a cape chisel and split the bearing, and at that point reach in and grab it and pull it out...or we used a dremel. Mind you, we did this when we knew we were going to do an in-frame overhaul on the big diesel stuff, so the block was quite bare at this point....but still easier than removing the engine or splitting it from an equally heavy and awkward transmission.

I don't think I would try this trick on an engine with the pan still in place, where the risk of dropping something is just to great ......one micro piece of metal is still two too many. I suppose the idea I should have mentioned was just the " poor mans " cam bearing tool, as opposed to opening up a big can of worms regarding the many things that can be done but perhaps shouldn't to an engine. I agree though, an in-frame is completely feasible on nearly any car, but if I have to go that far, Id personally rather pull it out and make sure its right.

Tip from Mikey:

Mopar RB engines ( and small blocks too ) like the 361, 383, 400, 413, 426W and 440 have shaft mounted non adjustable rocker arms. This means that if you have some serious lifter noise, you cannot adjust it. You may have a bent pushrod or a bad rocker arm where the pushrod end has worn out or maybe the rocker shaft has loosened. I have seen that last particular phenomenon on older 413's where the rocker shaft pedestals were not cast integral to the head.

If the lifter itself is worn and dished, replacing it with another lifter will just temporarily solve this. A new lifter on an old cam is just a good way to wear out a new lifter. It is possible that the lifter is just not pumping up properly, one of the few additives that I have ever had much faith in is Alemite CD-2 or Rislone, specifically for lifter noise may help this but if the lifter has collapsed then it is probably not going to help.

I would certainly pull the valve covers off and run the engine for a few minutes. You can easily spot the offending part this way.

Question from Dave (440):

A tappet has fallen down inside the engine of my '73 Imperial, and I have no idea how to go about retrieving it, or even where it is resting. The tappet doesn't seem to be anywhere in the valve-train alley. What part of the engine am I going to have to remove to find this errant item?


From Jim:

If you are confident that the tappet is in fact not reposing in the valley area, things don't sound too good. I can't think of a way for it to get down any farther though, unless the camshaft had failed...shall we say...catastrophically?

From Dick:

Is it possible it ricocheted through an opening into the timing cover area? I don't recall how big the holes are, or even if there are any in a 440 (my mind is still full of Packard 374 at the moment). If not, it still has to be in the valley area or perhaps it can find its way past the camshaft in which case it is in the glop in the bottom of the pan, where it might not hurt anything but I wouldn't take the chance. Also, running the car short one lifter will make an interesting tune-up problem.

 Follow-up from Dave:

I found the tappet! Taking the driver side valve cover off allowed enough light into the engine to reveal the tappet sitting in the back, in the middle of the engine.

Reply from Richard:

Most auto stores sell a $10 tool for just that job! There's a reason the tappet flew out of its bore. 1. It's collapsed: possible, replace. 2. Very low oil level: possible w/ lot's o' leaks. 3. Generally low oil pressure: Things age, 20w50 and/or STP could help. Had a buddy w/ a big block ford, spent all day putting the lifter back in, replaced a bent push rod and rocker, he blew the tappet back out w/in a week.


No, I don't think so. Assuming that we are discussing hydraulic valve lifter tappets, the total tappet length is the tappet bodies length. The top of the plunger, even when full extended, is BELOW the top of the tappet body. A spring retainer in the tappet body KEEPS the plunger below the top of the body.  All of the parts fit entirely inside of the body and a retainer keeps them inside the body. If the tappet is popping of the its bore it is due to one or more, of the following. (This is not an exhaustive list, but everything I can think of right now.) 1) Incorrect tappet for application - replace with correct 

2) Worn tappet - replace 

3) Worn tappet bore - bore oversize and replace with oversize tappet 

4) Bent push rod - replace 

5) Incorrect push rod for application - replace with correct length 

6) Worn or broken rocker arm, replace 

7) Worn, broken, bent, or incorrectly installed rocker arm shaft - repair or replace as necessary 

8) Worn or broken valve return spring 

9) Worn or broken valve stem The idea is too look for something that is extending the travel distance. Bent push rods are shorter, so the distance is greater. Broken valve stems also increase the distance. A broken rocker arm, shaft, etc. can move AWAY from the push rod and valve, also increasing the distance. The more space, the easier it is for the tappet to pop out. 

Addition from Dick:

In addition, if the tappet flew the coop when someone was working on the valve train hardware, the removal of a pushrod for whatever reason might have extracted the tappet from its bore if the suction holding the end of the pushrod to the lifter socket was strong enough to make the lifter overcome its weight and friction in the bore and follow the pushrod up.

Question from Philippe (392):

I've noticed for some weeks a noise in the valve train: it seems that I've one (or 2) noisy lifter.  But I'm not sure it's a real problem because: 

- for some weeks the weather is cold. 

- the noise occurs when the car has been parked several days with engine not running. 

- the duration of noise seems to be proportional with the time of non-running engine. But when engine is hot, there's no noise. 

- oil level is OK (1/10" below Full)

This morning I started the car (wasn't started for a week) in cold weather and it needs 5 to 7 minutes to stop the noise. Rather long!  Is this a normal condition?  I stop the car (w/o driving) and I restarted the car 7 hours later. The noise appears again but remains only 2 minutes. I made a 10 mile trip, stopped the engine (around 15 minutes) then restart: no noise.

Engine runs with 15W40 oil and I'll soon change oil.  What do you think of a 10W40 or 5W50 synthetic oil ?


From Dick:

Any Hydraulic lifter will leak down sooner or later, if it is stopped in a position such that the full 200# or so of valve spring pressure is pushing it down. After all, this is just two cylindrical, very well fitted and finished pieces of metal in very close proximity that are asked to hold back the pressure of maybe 1000 PSI! What I mean to point out is that there is no flexible lip or other compliant material to make the seal absolute.

When the lifters are new and perfect, and everything is spotless clean in the engine, they will hold up for weeks. As the lifters wear with use (wear occurs entirely on startup, because after the oil is circulating, they run in a bath of oil), they will begin to leak down faster and faster, and changing oil viscosity will only have a slight effect on how fast they leak down.

My advice regarding "CD-2" was with relation to a completely different problem, that of a lifter sticking due to a particle of crud keeping the check valve from seating. I would expect it to have no effect at all on a worn lifter, except maybe to make the problem worse since it will thin the oil somewhat.

From Leo:

I've been using Castrol Syntec 5W50 in all of my vehicles except the '67 Imp. (engine's not broken in yet) The lifters on the '56 Imp used to rattle occasionally after sitting for a few weeks. Now, with the synthetic oil there's no lifter rattle even after being parked for three weeks.

From Steve:

If it is indeed a valve lifter/tappet that is making noise, I'd replace or repair the tappet first. <--that's my .02cents.

By the way, I have always used 10W40 oil in every old Mopar or any other car I have had...probably totaling close to 1 million miles over the years with no oil related problems (except the oil-pump or relief-valve going in my long-since-gone '73 Imp)

From Roger:

It sounds like one of two things first 15W40 is to heavy for cold weather. In winter I use 10W30 in all my cars. You never said how many miles are on your engine. It could be just a adjustment. I would try changing to a lighter oil first.

From Jim:

I grew up with several "big block" Chrysler cars and they all had a tendency to have a noisy lifter or two. The lifters bleed down when the engine is shut off and once the oil is cold they have a hard time getting enough oil to pump back up. Sometimes running a can of engine flush right before an oil change will clean them up and stop it. I think that the 5w-50 oil idea is a good one.

Question from Tim (392):

What about noisy lifters after the car gets good and warmed up instead of when it's cold? My is quite when cold and gets a little noise in the lifters when warm. Is this normal?

Reply from Dick:

Heavier oil might help. If the lifter is leaking down when it is hot, the oil is escaping out of the lifter too quickly, either because the oil is too thin, or because the lifter is worn out, or because the oil isn't getting up there (because of low oil pressure).

Question from Johan (413):

I've got some occasional knocking in one of my valves from starting the engine (1965-413) with the petal all the way to the floor (BAAAAROOOOOMM tick tick tick tick...."woops-darn it!").  I had a hard to startup at one time, from one of those fuel additives a while back that has since gone away. Blowing a small amount of gray smoke when I accelerate hard too. Again the noise is only occasional and when I accelerate hard. possibly a lifter. Is this hard to remedy? Costly at the garage? Am I correct in the diagnosis?

Reply from Dick:

The lifters don't know what you are doing with the accelerator. If the noise is dependent on accelerator position, the chances are this is either a pre-ignition noise or a more serious mechanical problem. Try retarding the spark timing about 5 degrees to see if it goes away - if it does, relax. If it doesn't, start saving your pennies, it's probably a rod bearing.

The right way to start a cold MOPAR of this era is to press down the accelerator pedal about 1/2 way one time to "set" the choke, then release it, and crank the engine. If all is in good shape, the engine will start and idle without further touching of the gas pedal. This procedure is clearly stated in your owner's manual, also.

Question from Michael ( 413):

Okay, the lifters are starting to chatter...Rebuilt in 91 so they have not been tightened or fiddled with since.... How difficult, or should I just take it to the garage...I know that I have to pull off the valve cover gaskets to access them, but how tight and what other things should I look for... 


From Greg:

The lifters can be removed without taking the intake manifold off by using a special tool. disassemble them, clean in kerosene and reassemble. Put in fresh oil over night then reinstall. Never mix any lifter parts and reinstall all lifters in the original position in the engine....

From Norm:

If your lifters are clattering for no apparent reason, it is possible that you have overfilled the crankcase with oil and the higher level is making contact with the bottom end of your engine. This would cause a churning action which would aerate the oil with many little bubbles and , when the aerated oil found its way in to the lifters , would cause them to be starved for oil and thus make noise. It's a long shot, but then who would have bet on an aging former Film Star to become President.

From Dick:

OK, this is a hydraulic lifter engine. If the lifters are chattering, and it is only one of them, it is possible that there is a particle of dirt stuck in one of the lifters, and you might solve the problem by running a temporary boost to the oil's detergency. I have a favorite snake oil treatment, it has worked for me many times, often quieting a lifter while I am pouring it into the oil filler! It's called "CD-2" oil treatment. I do not in general advise the "mechanic in a bottle" cures for things, but this one works! 

If more than one lifter is making noise, you probably have a much more serious problem. The lifters are starving for oil, either due to a failed oil pump (not likely, or you would see very low or zero reading on your oil pressure gauge) or more likely, one or more failed bearings, typically a main bearing. This would also produce a pronounced dull bottom end knock on first starting the engine after allowing the car to sit overnight. If this is your problem, or if you hear clatter from the rods at high RPM, its engine time, sorry Do not continue to operate the car in this condition, you risk serious damage to the block and/or crank.

Follow-up from Michael:

I think it is a single lifter Dick...I hear it mainly when the engine is cold, and at a low idle...when the idle is increased, it ends, and when the engine is really warm, it is almost not noticeable.... Oil pressure is okay, no major knocks...Just that annoying little clatter...I will try the treatment...

Reply from Dick:

If the detergent boost doesn't clear it up (let it work for a few hundred miles before you decide it isn't going to work), the next step is probably to replace that one lifter. In some engines, and I do not know if a 413 is one of them, (Help, somebody) you can pull a lifter by just taking off the sheet metal valve cover and one rocker arm, or perhaps all the rockers come off in an assembly, and then remove the pushrod from the offending lifter. If the engine has a big enough clearance hole for the pushrod, you can fish the old lifter out with a long piece of wire with a little hook on the end. Then simply oil up the new lifter, drop it in, reassemble and "Bob's your uncle", as our forefathers used to say. No need to get involved with removing the head or the intake manifold.

 From Richard:

I've pulled a couple of lifters out w/ the manifold still bolted on and can't imagine using a coat hanger to do it, but if Dick says it can be done.... Most auto part chains sell a $10 tool designed for just such a job. It's kind of like the screwdrivers that have a tip which expands to hold a screw by it's slot, except that the tips are angled to get a hold of the lifter body. A lot of the times the lifters will just slide out of their bores, however it's not uncommon for them to get 'stuck' in the bores, even though they still move up and down w/ the cam lobe. The positive grip of tool allows you to fight them out of the bore as well as keep a solid grip on them while trying to figure out how to corkscrew them through the openings in the head.

Follow-up from Dick:

Whoa, not a coat hanger! You'll need a much smaller diameter wire to grab the lip of the inside of the lifter. I have done it with a piece of #16 piano wire (about 1/64 diameter, but very strong, and holds its shape). The tool sounds like a better idea, though, if you can find one. If the lifter is resistant to coming all the way out of its bore, try a generous shot of WD40 down the hole to dissolve the build up of gummy oil residue around the top of the bore, then work the lifter up and down 157 times or so until it finally can come clear out without hanging up.

Question from Chris:

I am having a problem with a sticky lifter.  Any ideas how to cure it?

Reply from Dick:

Here is my cure: This is usually caused by a particle of dirt in the lifter, and most likely, if the car has been driven this way for a long time, it isn't going to yield to the following, but it's worth a try. Get some "CD-2" oil additive and pour it in the crankcase. I have seen noisy lifters quiet down while you are pouring it in! This is a booster for the detergency additive in the oil, and is the only case where I have ever recommended that someone use the "mechanic in a bottle" approach to curing a problem with an additive.

Question from Dan (440):

I'm making progress (slow) on my '67 Crown. I want to get everything mechanically sound and then focus on the cosmetics. So far I've flushed it out with marvel mystery oil, changed fluids, filters, plugs, and have been driving or running it periodically to keep things moving around. It sat for quite awhile before I bought it three weeks ago.

A lot of white smoke comes from under the car when it first starts and it lays down a patch of black on the ground under the tail pipe. After 3 or 4 minutes it all clears up - both colors of smoke. What concerns me is a "LOUD" lifter noise. I believe it's only one because it stands out from the rest. Tonight, after reading a post from one of our members who said his noise went away 5 to 7 minutes after starting in cold weather, I decided to see if mine would clear up after running for awhile. I increased the RPM to a high idle and let it run for 20 to 30 minutes, keeping a close eye on the gauges. The temp here is in the 60's. The engine temp and oil pressure remained fine and the coolant stayed full, but the noise did not reduce at all. It's loud enough that I don't really feel comfortable running it much. At first I wasn't concerned because I thought it could be adjusted like I used to do on my old 283. But after talking to a mechanic today he mentioned these are different and it might not be that easy. Can anyone suggest how to proceed from here? If these are solid lifters can they be adjusted? Also, I suspect I might need a valve job with new seals. What should I expect to pay for a valve job with new lifters, cam and bearing? Also, what is a fair price for honing the cylinders and installing new rings, if that's needed too?


From Steve:

There would be no adjustment on these valve lifters as they are hydraulic lifters. I would pull both valve covers and verify that you don't have some rocker arm problems. You could even run the engine for a short period of time with the covers off. Chryslers don't usually spray oil all over the place when they're running like small block Chevys do. If all the rockers arms seem to be OK, it isn't a major project to install new lifters. Make sure if you do replace them to do the complete set and kinda watch the bottoms of the lifters as you remove them. If you have one or two that seem to be worn concave instead of the normal convex, you could have camshaft problems. I don't recall ever seeing a "flat" Mopar camshaft though.

From Dave:

You may just have one collapsed hydraulic lifter, spring weak or gummed up or something. Pull the rocker assy off and find the culprit and replace it...maybe the pushrod, too. If all the rest are nice and quiet and seem to be working good.

Question from Kerry (440):

Ok, I'm stumped. I have this click on my 73 440 that sounds JUST like a lifter. After a several miles it goes away until the engine sets for a while. A few weeks ago, I decided I was pretty sure it was #7 and was able to install two new lifters. No change in click! Maybe its an exhaust leak. Planned on tightening the manifold when I pulled the hood and today I did just that. While my son was there to help, I had it put in gear and give it some gas to load the engine. Click was very noticeable and appears to be coming from the rear passenger side. Pulled the #7 plug wire and click disappears. Remember those are two new lifters. What do you think is causing the click? Is it an exhaust leak on the rear of the manifold or possibly one of the new lifters was bad????


From Dick:

I'm a little confused here. You mention #7, but that is the rear cylinder on the driver's side, not the passenger side. If this is just an error in cylinder ID and you meant to be talking about the rear on the passenger's side, then I understand why it would go away when you pulled it's plug wire. This would indicate to me that the problem is probably a bad exhaust manifold seal to the block or (more likely) a cracked manifold. Either one typically will shut up when the engine gets thoroughly warm. To track it down, get a piece of garden hose about 4 feet long and stick one end upside-a yo' head, then wave the other end around the area on the engine that makes the noise and see if you can track it down. (This is a poor man's stethoscope.) A bad lifter or a bent pushrod will sound very much the same, but it will not make any difference whether or not there is a load on the engine or no spark to the cylinder, it is simply a mechanical clearance problem, which will be independent of any other conditions. Another mechanical problem that will sound like a snapping noise is a loose piston pin, but that will change markedly with different loads on the engine - it gets really loud when it is pulling hard at high RPM, and is nearly silent a lesser loads. This will not change with engine temperature, so I doubt it has anything to do with your noise.

From Dwight:

I know this may sound silly, but check to make sure that you do not have a short in the plug wire for #7. These can sometimes be very loud and sound like a mechanical problem...as someone else already said, pulling the wire will not make lifter sounds go away. If you do this in the dark, you can often see the arcing where the short is occurring. if that is what it really is. I doubt that you have a lifter problem from what you have said.

From Brad:

I bet on an exhaust leak. Manifold gasket or cracked manifold.

From Norm:

2 out of 3 of the 413's and 440's I have owned have done this. Even when nearly new. I always assumed it was an exhaust irregularity because it always goes away after a mile or so.

From Steve:

It sounds to me that it is the usual exhaust manifold leak. Pulling the spark-plug wire off would have no effect on the lifters. Is the engine running smoothly?? If it seems to have a skip, maybe that clicking noise that you are hearing is an arcing plug wire. Those manifolds are prone to cracking. A wise old man told me the other day that they crack due to "shock-cooling"...which is caused by splashing thru a large water-puddle big enough to douse the hot manifold with cool water. Check to see that your splash guards are in place in the inner-fender wells near the control arms. They are there to keep the H2O out.

Tip and Question from Jack:

I had a wicked lifter knock when I picked up my car from the mechanic. I stopped by the auto parts store and got the famous snake oil, CD-2 damn, if it didn't cure the lifter knock within about 3 miles Before the timing chain was replaced, I was plagued with ever increasing backfiring, then the chain slipped a cog and the car ran lean for about 150miles, (while I was getting home) I still have a kind of rough running car. like a miss. Would a compression test be of value at this point?

Addition from Mike:

Count me among the success stories....I used it 6 weeks ago and it cured a stuck lifter in my '56 almost that quickly!

Addition from Brad:

My LeBaron is bed (garage)-ridden due to a leaky pumpkin seal. (Santa has promised to bring me a 3-ton floor jack for Christmas so I can fix that). I start the car every couple of weeks and let'er warm up. I've always have a slight lifter tick at the #1 cylinder and figured it was time to try and remedy that. Another problem I was having was that after my last oil change (the only one since I've owned the car, I've only put 500 miles on it) was a slight rod knock, seemingly from the #4 piston. I figured that I had freed up a piece of crud when I changed the oil and it has lodged in the rod's bearing orifice. Same thing happened to me with a CAD* I owned. A little driving had cleared the Caddy's knock, but that didn't help the Imp. I'd driven the car around the neighborhood and back into the garage and it still knocked slightly. That was 3 months ago. Back to the present. Time to try the CD-2. I started up the old girl and poured it in. Within 3 or 4 minutes the lifter noise got lighter and lighter......and finally quit altogether. I was still quite concerned about the (albeit slight) rod knocking. As the car got warm and the temp gauge approached normal (for mine) I went to the back of the car and could see the steam blowing out of the pipes. I covered the left pipe and forced the exhaust out of the right. About half a cup of water poured out and I felt bad for those right-side mufflers. They probably keep a lot of water in them. I need to get the car out for a good long drive. I'd forgotten about the rod knock in the 5 or so minutes I was force feeding the right exhaust pipe. When I went back to take a listen.....nothing, zilch, nada! I was really worried I'd have to do major surgery if this hadn't done the trick, but it did. The engine runs smooth enough to balance a nickel on the air cleaner lid. What a relief! I let the car run for about 25 minutes total. The motor remained quiet and the temp remained normal. All traces of water vapor finally ceased from blowing out of the exhaust.


From Dick:

Yes, if the car is still running rough, by all means do a compression test.

From Bill:

I am always amazed when someone has success from adding an additive. I have always been skeptical of any such products, never having success with any myself. I presently have a what I thought is a terrible lifter noise but after following Kerry's thread now question whether it may be a leaky exhaust manifold instead. Need to try Dick's "Poor Mans Stethoscope" and pin point it down. In regards to your miss, have you checked the plug wires and distributor cap?

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