Atok

Ok, this is starting to annoy me. Installed a new set of GMPP LT-4 rockers, springs, retainers, locks on my LT-1. Adjusted the lash to 1/2 turn.

The rockers on the right bank are terribly noisy. Left side is very quiet, better than the old stamped steel rockers actually. The noise on the right side doesn't sound like a single rocker, it sounds like the entire bank or at least multiple rockers. At 2000 rpm or so it sounds somewhat like a collapsed lifter - on and off.

The noise is very clear when listening with your ear at the same left of the front tires. On the left side it's virtually silent. On the right it's very mechanical sounding. When the engine is hot it's louder.

I added another 1/4 turn of lash and it made absolutely no difference. Next I'm going to pull all the rockers off the right side, closely inspect them along with the pushrods, then reassemble and adjust to 3/4 turn again.

Can anyone relate to this problem? Have similar experiences? Can it be a lifter problem? The car runs smooth and strong.

Thanks

VR'92

I've had this problem with the same GMPP RR's. What finally fixed it for me was changing the lifters. I think my return springs were weak and I was not seating the rockers properly due to this.

This stopped my ticking I kept getting but still these RR's are a still little too loud for comfort.

I'm thinking this may also have to do with uneven spring height.......

Atok

Yeah, I am suspecting the lifters, but why only on one side??

VR'92

I have no idea. My right side has always seemed louder than the drivers side. I'm not sure why.

steve40th

Is the geometry of your valvetrain correct on the right side? reason I ask, were your heads milled? Angle milled? Swap left rockers with right? Adjust while running.
There is a lot of things that it could be.

Atok

No, nothing done to the heads. Bone stock and only 50k miles or so.

Switching the rockers around is a good idea. I might try it and see what happens.

Atok

Ok, I pulled all 16 rockers off. Closely examined them along with the pushrods, valve stems, studs, etc. No problems found, everything looks pretty. So I swapped the right and left bank of rockers and re-adjusted to 1/2 turn preload.

I still have a noisy valve train on the right side only. So apparently it must be a bad lifter. Damn! I guess I'll try some of that Wynns cleaner first. If that doesn't work then I guess I'll be pulling the intake....I hate the noise.

I did find part of the problem. #6 plug wire was not clipped onto the plug. Only the rubber boot was holding it in place. So it was arcing between the wire and plug, but the plug was getting enough juice to fire. My idle was "slightly" rough before but not what I would call a misfire. Might of been contributing to the "ticking" I'm hearing. Anyway, I find it interesting that the Opti puts out enough juice to fire across two air gaps.

Anyone know of something that works better than Wynns for freeing a stuck lifter? Wynns did a great job on my old 1/2 ton truck.

Anyone have an opinion on Lucas Oil Stabilizer? Just looking for something easy and not bad for the engine so I won't have to swap lifters to get rid of the noise!!

steve40th

I saw a video of the Lucas stuff, it airates stuff pretty bad. I wouldnt recommend it. If the lifter is stuck, it needs to be replaced IMHO. There relatively cheap comapared to possibly floating a valve etc.
But Wynns is good, try it, and let it set for a while, follow instructions etc.