Randy V

Short of replacing them, is there a proven way to quiet the lifters?

I've added a couple pints of the stuff Greg Brown recommends - Swepco I think it is?

That helped quite a bit but didn't totally eliminate it.

In previous cars I've added a pint of transmission fluid to the oil and ran it for about 30 minutes, then followed that with an oil and filter change and adding 2 pints of Swepco. That procedure worked immensely well.

Any similar hacks to try?

Strosek Ultra

http://jenniskens.livedsl.nl/Technic...7/MyTip795.htm
https://rennlist.com/forums/928-foru...c-lifters.html
https://rennlist.com/forums/944-turb...onic-bath.html
Åke

SeanR

Don't you have new lifters in that engine?

SwayBar

Can you describe the noise they are making?

Are you sure it's not the fuel-injectors you're hearing?

Randy V

It's definitely the lifters, no question.

Kevin in Atlanta

Have they always been loud? Is it ll of them of just a few? Last oil change? How's the oil pressure? Loud at startup? Louder when the engine is hot?

I assume you tried the Italian tune-up.

Randy V

Sometimes they are quiet, other times terribly loud.

Mrmerlin

Randy do you see any oil pressure changes from past operation
IIRC your engine was rebuilt
When that happens the heads are cleaned
one issue I have seen has been where the oil anti syphon lower seat can work itself loose and the oil can push it up and then the oil feed port gets blocked
this can reduce or cut off oil to the head and worsts case the cams will seize are the lifters that are making noise from one head or both

We lost a head and set of GT cams due to this issue after a po had done a valve job

I suggest to inspect the lower seats to verify they are loctited and peened in place
you might pull the dipstick and drop the oil onto a piece of black card board look at the oil in the sun if you see lots of metallics then your making metal

Randy V

Thanks, Stan.

No concerns about improper installation or internal failure. My engine was rebuilt three years ago. Any significant problems would have manifested by now.

It seems the problem is the lifter oil passages are compromised. I'm hoping that using an aggressive oil additive cleaner followed by an oil/filter change using a lower viscosity oil (I currently use Mobil 1 15-W-50) and Swepco additives will cure the problem.

I'll have Greg Brown do this during my next visit.

Mrmerlin

Randy is the noise coming from both heads?
If so then it would rule out my suggestion about the lower oil seat coming loose

GregBBRD

The original lifters with 250,000 miles and the original cams are in this engine.

Amazingly enough, the cams were very nice and we decided to leave those.

I wanted to install a new set of DLC lightweight lifters, at the time of the rebuild (partially to "protect" the cams from any further damage), however other necessary items consumed the budget.

There's nothing wrong internally. The engine has a few lifters (unknown how many, but at least two) that do not "hold pressure", if the engine happens to "stop turning" with the cam lobe pushing down on these lifters.

The lifter noise goes away, after a short period of running.

"Chemicals" do not seem to be curing this problem. My guess is that some of the tiny springs that hold the check ***** against the seats have broken/worn out.

It needs a set of lifters. When this engine was done, I was using lightweight VW lifters that we took apart, sent off to Beckhart for polishing and DLC coating, got back and cleaned and re-assembled. I felt so strongly about the benefits of lightweight DLC lifters that I provided this "service" as a "loss leader", charging $100 per lifter and loosing money on each one!
The good news is that we now can buy this lifter for ~$50, because another major company had lifters, like the ones I was usin made for themselves.

Mrmerlin

I wish I had taken a few pictures of this GT engine that had this oil failure , so you could to see how the cams seized into the heads and then the belt finally snapped.
The spring that held the ball in its seat was blue and squished together and the ball was a sintered gray,
the lower seat was pushed upwards and blocked off the oil passageway.
A very strange failure.

GregBBRD

Indeed!

That falls into the category of:

"If it can, it will."

Right?

SwayBar

Here is the exact VW lifter you need:

Lightweight VW Lifters...

I believe Twin Turbo Todd-ster uses these with no additional secret sauces.

GregBBRD

Yes, this is the lightweight lifter I used to use, take apart, and have DLC coated. Beckhart would "reject" about 25% of the ones I sent them, because of "hot spots" under the top coating, caused from grinding them too quickly and getting the lifter too hot.

It got to the point where I'd have to send 50 lifters, in order to be sure I would get 32 lifters back....and a couple of times, this wasn't enough.

I would never use this lifter in the "raw" stste, because of the problem with the hidden "hot spots"......928 cams are way too expensive to mess around with sub par pieces.