Valve train noise after rebuild

an87ttype

New Member
Joined
May 24, 2001
I've got what I think is a little extra noise from the valve train. I'm using a CompCam 206/206 with GM lifters. The preload is between .035/.040. It sounds like a lifter but it only makes noise at between 2300 and 2500rpm. Its not too loud but loud enough to make me wonder. It made this noise from day one. I've got about 600mi on it now and it still sounds about the same.
Any idea if this is a big problem? How can I figure out which lifter it is?
Any help is greatly appreciated.................
 
86-TType
87-Turbo-T


Ok, now to the problem. Most of the Comp Cams always give a little noise so if you aren't getting any metal, it isn't backfiring, don't worry too much about it as you may just be chasing your tail.
 
sounds like a double roller timing chain or a stock style with a weak or broke tensioner

if its double roller get use to it
 
So you think it might be my double roller? Is that something that slaps around at certain RPM or is the cam moving? It kind of sounds like a lifter.
Thanks, the more suggestions the better. I will take it apart if I have to. It just looks so good in there right now I hate to start ripping it apart again.
 
Did you re check the pre load since original assembly? Maybe they need to be adjusted again?

Butch
 
It could also be your cam sensor, mine makes a bunch of noise around that rpm range. check it out
Good luck.
Mike
 
I've checked the cam sensor with the screwdriver to ear test, I also had the valve covers off and re-sized my adj. push rods. Preload is 035/040. I understand that .060 is the max, true? It sounds like its coming from the middle of the motor but who knows. If it helps, you can really hear it while going slow with the windows up at 2500rpm. Totally reproducible with the rpm.
Other than a little tip-in stumble it runs good tho I haven't really floored it for any length of time yet. I still want to let it break-in a bit more before turning the boost up.
Any other ideas or diagnostic tips?
Thanks again all!!
 
You are OK at .035 preload. I have seen .060 preload wipe a loab on the cam. I use Comp cams and they will make a little more noise. The valve train noise is normally at idle and not a 2500 rpm.

How does your oil look? Not on the dip stick but after you drain it and it has sat in a clean bucket. Does it show signs of metal meterial?
 
still sounds like chain slap to me. i delt with it forever on my hotair motor with double roller so i went to stock replacement and much better.

like you said between 2-2500 rpm next to a curb was the loudest.
 
I'm going to have a few more people listen to it this weekend to see what they think. It's kind of hard to diagnose without hearing it in person. Too bad I can't post a tape of it somehow.
I'm also going to change the oil this weekend to see if all the break-in metal is gone. The last change at 500mi looked pretty clean. just a few specks in the filter.
Thanks all, any more suggestions?
 
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