The Stovebolt Site Forums The Shop Area Engine Shop Need Help With a Stuck Hydraulic Lifter

Has anyone been successful with using an oil additive to free-up stuck hydraulic lifter(s)?

You can try Sea Foam, diesel fuel, a retail engine flush, maybe a little gasoline, kerosene, any of those are a solvent that help dissolve sludge, varnish, carbon. Add it to the oil and keep the RPM low. I have used an engine flush from the national chain FLAPS, it has worked on noisy lifters in engines with poor maintenance. If you are religious about oil changes and the oil pressure is normal, you may have issues that an additive can't fix.

The problem with these aftermarket lifters is lack of quality control. Invariably you will get one out of the twelve that will hang up internally until the engine warms up right out of the box. I am on my third set of these lifters and that has been my experience on all three sets.

Hey Carl, I may have asked you this before , but what setting are you adjusting your lifters.

Tighten adjuster 3/4 turn once I take the slack out and feel resistance while manually turning the push rod.
I have experimented with 1/4, 1/2 and 1 turn on the noisy one which hasn't eliminated the the cold engine clack.
I have also attempted to adjust the clacking lifter while the cold engine was running, but couldn't make it go away.
It goes away once the engine is warmed up.

I’m not going to say it will fix your problem, but the book calls for 1-1/2 turns.
If set any amount less then that the spring inside the lifter is not compressed enough for it to have the force needed to push the plunger up against the push rod and fill the working area inside the lifter with oil.
In some cases setting the adjustment at 1-3/4 turns will fix the problem. You don’t want the over tightening the adjustment much more than that or you run the risk of holding a valve open a bit.

I stand corrected. I left the "1" off the amount of turns. I did go by what's in the book and tinkered with different increments between 1 1/4 to 2 turns to try to find the sweet spot which just was not there.

I know you have been struggling with this.
Sorry it hasn’t worked out.

Remove the offending lifter and dismantle it. Mirror polish the plunger with a hard felt buffing wheel and jeweler's rouge or a similar grease-based polishing compound. I use the same type of polish to prepare firearm parts for bluing.
Jerry

The design of the early stovebolt hydraulic lifters did not provide a pathway for trapped air to be purged from the lifter bore. Later designs used a tiny pinhole in the pushrod seat to allow for a small leak to happen, which allowed the trapped air to escape much more quickly. I have seen several modification procedures to the lifter and the bottom of the pushrods suggested to create a very small amount of leakage to accomplish that kind of air displacement. BTW- - - -Lincoln Zephyr V-12 engines in the 1930s and 40s also used a very primitive design of hydraulic lifter, and they had similar problems with noisy lifters on a cold start.
Jerry

Jerry, What color rouge? There's white, red, green and maybe more. All different coarseness.

I use a grease based white rouge sold by Brownell's gunsmithing supply called "555". It produces a mirror shine final finish after polishing with a series of coarser media polishing steps. The idea is to eliminate any roughness that might be there during manufacture of the lifters. It works best with a large diameter (8") hard felt polishing wheel and medium speed when preparing firearms for hot tank caustic bluing.
Jerry

My push rods have grooves in them to let air out.
One day I may go to the trouble of removing the hanging lifter and polish the plunger. My side cover has a leak in it anyway and I have a spare gasket in stock.