Packard Forum Index » V-8 (1955-56)

Good morning- I hope you knowledgeable guys can help me. I have a very nice 1955 400 I just got. The car was beautifully restored and the few leaks it had were fixed. I understand these engines were prone to a valve lifter noise and mine has it, especially when the car is run on the highway and is hot. When it is being driven local the lifter noise comes and goes. The engine has plenty of power, uses no oil and the drain oil is pretty clean. I tried the remedy of using a heavier, 15-40 oil and STP but it does not help. I'd like to avoid tearing down the engine. If I run it the way it is will I damage something? Please advise and thanks

The intermittent noisy lifters has been an issue. There was a change to a different lifter and some changes to how oil is delivered to various places in the engine almost immediately after 55 production started but those changes only partially helped. The noisy lifters has remained an intermittent and something not happening on all engines problem. You can look thru some of the early 55 Service Counselors in the literature archive and find articles on the changes.

Later on Packard did find some issues with the original oil pumps and suggested dealers make a replacement to cars with continual complaints. They also made another stop gap change to the pressure relief valve because of thoughts air could be entering the oil stream thru it. Again, since it did not happen to all engines no conclusive reason was ever found before Packard went away. If the car was serviced by a Packard dealer when new or was of later production chances are you have most of those upgrades.

After Packard went away many former mechanics came up with other theories such as a plate on the aux vacuum pump in the crankcase was swelling under pressure and allowing air to enter. One of the clubs offered a pump modified to remove the vacuum section entirely. Another theory is the oil pump shafts were unsupported, wearing the cast iron housing and wobbling allowing air to enter. Reworked pumps with a bushinged shaft were offered there.

The latest "fix" eliminates the factory pump entirely and replaces it with a Melling pump made for an Oldsmobile. So far this approach has seemed to be the best offering as I don't recall any of those who made the change reporting the lifter issue using the standard Olds pump. A few have installed the Olds heavy duty pump and while no lifter issues, do report oil leak problems -- most probably due to the larger volume flow overwhelming the old rear main bearing sealing method.

You might check and see if your pump is the original. If so replacement might be worth looking into. It is a comparatively simple change only requiring an oil pan removal. If the original pump with aux vacuum section is still present then some changes to wiper vacuum supply will also be needed. I believe Jack Vines is selling the pump and needed mounting plate kit.

I had the same problem with my 56 Patrician. It is a design flaw in the oil pump. You can try running with one quart over full. I did not have any luck with that solution, so I had the pump rebuilt by Bob Aller. That worked for a time but then the problem returned. I recently bought the OLDS pump conversion kit and had it installed. Oil pressure increased but I am now leaking oil out of the rear engine seal. Good luck with whatever fix you use.

Gents I very much appreciate the speedy replies. My only other question is this ? If I run it the way it is will I damage something? Please advise & thanks

Mechanical noises like that are not good. If that problem was being looked at in engineering today we would be installing pressure transducers, thermo couples, and opticals into the oil gallery to see what is going on with the oil.

Given those motors seem to like to burn out number eight rod bearing, which is closest to the oil pump, my presumption is the problem may be aeration caused by the oil feed changing direction to the rear bearings. People have scoffed at this idea but we had problems like that in systems operating at 450 PSI. The engines weren't running right until a bend in the flow path was changed.

What the OLDs pump does is provide higher volume at lower RPM because it is a gerotor. The Packard gear pump supplies higher volume than the OLDs pump at high speed. That is why they could run that motor wide open for 25,000 miles without noises, but then problems were showing up at moderate speeds.

Thanks for your reply. I have no problem with spending money on the Olds pump but I am seeing that this fix will cause leaks from the rear main seal. I just spent $8 grand on work and a big part of that was the replacement of the rear main seal. I would hate to blow that out. What do you think the damage might be if that lifter let go ?

Before I rebuilt the engine in my old '56 I would get a couple noisy lifters whenever the level got down to "FULL". With a quart over she was quite well behaved. This was standard procedure with the oldtimers in the Packard Club back in the eighties when several were still using V8 cars for daily chores.

Well yes, if you leave the lifters always making noise you will end up with damage. All my experience points to aeration of the oil as the culprit and the source of the air is where the shaft enters the pump. Keeping the oil over full floods that juncture and hinders ingress of air. That works only up to a certain point, but it is a very easy bandaid.

When I rebuild those pumps I cross drill the exit passage so it supplies oil under pressure to the bushing area.

I purchased a 1955 Patrician. Very low milage of 6,972 miles. It had been parked 40 plus years. Ran pretty well but loud lifter noise. Turned out 5 rocker arms clogged and had worn down the 5 pushrods at rocker arm socket. If your car was parked for years check this first. Cost me gaskets and 5 NOS pushrods. Runs very quiet now. It had no oil pressure problem with rocker arms end of the oil line.

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