Cams removed. Help me find the bad lifter!

JD159 · 10-01-2014, 07:23 PM

I managed to get the cams out of the car tonight!. I'll be able to take a picture of each lifter. I have kind of narrowed it down to exhaust valve lifter around cylinder 3. Some show a slight discoloration, seem to have the marks of bore rotation, but a number of that have some scuffing.

The lifter that I suspected was bad did not appear to have any obvious mechanical issues. I'll have access to a solid vice tomorrow to try and depress them because I cannot at all with my hand.

Keep in mind my symptoms only appeared when the engine was hot. So from my research that is the sign of a lifter that has leakage.

JD159 · 10-01-2014, 07:25 PM

JD159 · 07:34 PM

Could this be the result of an improper break in? Lobes still look good. Im considering maybe changing all 16, again, and doing another break in - myself.

DannoXYZ · 10-02-2014, 12:49 PM

1. What kind of oil are you using?
2. What is oil-pressure reading at idle when you first start it up?
3. What is oil-pressure at idle when warmed-up?
4. What is oil-pressure at +3000rpm when driving after warmed-up?

JD159 · 10-02-2014, 02:57 PM

Brad Penn. Then 10w40 amsoil in winter and 20w50 zrod in summer. Oil pressure always normal. My lifter noise was only present when hot, out of one lifter. I suspect leakdown on the broken lifter.

DannoXYZ · 10-03-2014, 05:09 AM

Could be crud clogging up the lifter's oil-holes.
Remove each one, turn upside-down and push on the button in the middle.
If you've recently turned off the car, they should all be pumped up and hard.
The clogged/bad lifter will be the one with the soft squishy button you can push into the body.

You can try soaking it in solvent like acetone/lacquer-thinner and push the button up & down repeatedly to pump the solvent into the lifter. This may dissolve the crud inside and you'll see a brown cloud seeping out of the lifter into the surrounding solvent. Then repeat the pumping with the lifter in oil to see if it fills and locks.

JD159 · 10-03-2014, 06:21 AM

All lifters are solid. Again, my issue was not on cold start, but hot. It is indicative of this condition..

"Noisy when engine assembly is idling slowly or when engine assembly is hot. Lifter
assemblies are quiet when engine speed is increased or when engine assembly is cold.
This may be caused by high leakdown rate in one or more lifter assemblies. Replace any
suspect lifter assemblies."

Having said that, it is tricky to diagnose because I can't quite replicate the hot oil temperatures. I spoke to Greg Brown in Anaheim and he agrees. I tried swepco 502 as a cleaner and it didn't do a thing. He said that clogged oil passages in the lifter probably aren't the cause of my problem. More the leakdown of a specific lifter.

How do the surfaces look? If they are not wearing properly I'll change them all and repeated the break in procedure.

mhr · 10-03-2014, 06:57 AM

I can tell you that after 108k on my S2 despite a known oil pressure problem the surfaces of the lifters showed almost no wear certainly nowhere near what is visible on yours. I am not sure if this indicates a problem.

good luck

Mark

951S/928S · 10-03-2014, 10:45 AM

The lifters should be highly polished, not scuffed like yours. I would suggest that you change all the lifters. If these surfaces are not perfectly smooth, they will eat the cam lobes. What do the lobes look like? Is there any wear or pitting? If so, you will have to change the cams also.
When the lifters were dropped into the head, were they lubed with assembly lube? we use the lube to hold the lifters in, while we turn the head over, as well as the lube on the surface protects the lifter and cam from dry start up. When the motor was started, did you pull the DME, and crank it until you had oil pressure, before starting it? If these steps were not taken, the motor will have been started dry, and this could have damaged the lifters, as well the cams, not to mention shortening the life of the crank bearings.
Was this motor rebuilt due to a rod bearing failure, or a cam tensioner failure? If so, there may be tiny metal filings floating, which could have entered a lifter, causing it to collapse. This may also account for the scuffing of the lifters.