Re: Hydralic Valve LIfter Problem

Posted by HH56 On 2022/8/22 11:04:29

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.