I narrowed down a weird squeak in my engine to the exhaust lifter on cylinder 8. If I pull that rocker arm, the squeak stops. And I ruled out all kinds of stuff before I got here. So I'm certain it is related to the exhaust valve train of cylinder 8. I ruled out the roller rocker by swapping it with another one. I ruled out any weird contact with the guide plate by removing the guide plate. (All of this testing is just idling in the garage with a modified valve cover that is open at the top.) I only hear the squeak after the engine is warm and only when idling or driving slow through parking lots. I don't hear it driving on the road, but I'm sure that is just because of the exhaust and road noise.

The lifters are Comp Cams Hydraulic Rollers. The heads are Trick Flows and the rockers are Comp Cams Pro Magnums. Cam is from Cam Motion. Has anyone experience this before? Is there anything else I'm overlooking it could be beside the lifter? What about the lifter could be squeaking though? It doesn't appear to be the roller itself, since it not a continuous squeak, unless it only squeaks when it is lifting the valve. Could it just be squeaking in the lifter bore of the block? Or maybe something internal to the lifter? Please don't tell me it's the cam. Could it be the cam?

I haven't pulled the intake yet, that is the next step. Just thought I'd get some thoughts from Team Camaro now that I've narrowed it down as much as I can without tearing into the engine.

Thanks,

Ray

Ray: Has the valve lash changed at all on that valve? If not I would say cam is good. From what you already elliminated I woud suspect lifter. You could change lash (with motor running) to see if noise changes.

I would suspect a bad roller on the lifter. Hopefully it hasn't hurt the cam. I would not drive it anymore untill you take the intake off and check the lifters.

I had the same noise on my small block 406 and drove it a little while like that. When I tore it apart the lifter and cam was bad. This was a solid roller setup.

Like Mike said .... dont run it another second till you pull the lifters and see what is going on. The whole set should probably be replaced if one is making noise.

I had that same strange squeak it would come and go. but a very distinct squeak. The roller had what I would describe as a gouge across its face. It would roll fine until the gouge caught and stopped it from rolling and it would squeak until it started to roll again. I ended up replacing all the lifters and the cam.


TTFN
Mat

Thanks for all the input guys. I don't plan to drive it anymore until I fix this. I hope to get the intake off tomorrow, if I can squeeze that in between family obligations.

Next question. I read somewhere this past year or so that GM now makes a "plastic" lifter holder, similar to the one in the LS engines that lets you run factory style roller lifters in older gen1 blocks. If I decide to get all new lifters, I've considered using stock style rollers instead of the much more expensive "retro" rollers like I have now. Does anyone know the part number for these holders? I don't know the magazine issue I read this in. Has anyone used these? Is this a viable plan, or should I stick with the retro style linked rollers?

Thanks again,

Ray

If you swapped out the lifter and the sound was still coming from the same place, I would think the that there is something else. Could you do a leakdown test on that cylinder? I am thinking something along the lines of a bad valve, cracked cylinder head, or possibly a leaking head gasket.

Ray: After removing lifter roll it across your finger, if you feel any roughness in bearing replace them all.

Deerhunter - I swapped out the roller rocker to confirm it wasn't that. I haven't swapped out the lifter, I haven't removed the intake yet. Once I get the intake off and pull that lifter I should be able to see the problem. I was just checking other people's experience to see if there was anything else I might should expect to see once I got in there. Also I've opened/closed the valve repeated manually with a valve spring compressor and it is smooth with no squeak.

Right now I plan to have to at least replace that one lifter and possibly think about replacing all lifters just to be safe. I will also inspect the cam lobe, and may end up having to replace the cam too.

Thanks again,

Ray

My face is red now! I could have sworn I read that you swapped it. Thirty lashes coming my way. Sorry about that. I have to agree with the others on this. Hopefully not another Comp Cam failure!