Chirping/ grinding sound from valve cover

**dethinboots** · 09-06-2016, 12:40 PM

Through the process of elimination I have determined that the sound isn't coming from an exhaust leak or a squeaky belt. From what I've read, I think the sound is coming from a lifted scraping the cam. The sound begins from a cold start and eventually disappears. How detrimental is this to the engine? Should I stop driving until I fix the problem? (New cam and heads waiting to be installed). I haven't noticed any difference in performance, I just don't want to break anything.

***SMWS6TA*** · 09-06-2016, 01:45 PM

STOP!!!!!!!!!

If you wipe a lifter or cam you'll be doing a hell of a lot more than a C'H swap.

**dethinboots** · 09-06-2016, 03:15 PM

will the swap fix this issue? any way I can be sure of the culprit?

**dethinboots** · 09-06-2016, 04:05 PM

The sound is only present from cold start and is gone by the time I reach operating temp. If this helps any...

**Naaman** · 09-06-2016, 05:11 PM

Is it possible this is piston slap? You have an LS2, so I'm not sure if this issue carried over, but, some LS1s are known to have piston slap during initial start up, and the noise goes away after op temp is reached.

**dethinboots** · 09-06-2016, 07:03 PM

I think Ive found the problem, and its an exhaust leak. The header bolt farthest forward on the passenger side broke off (during install I guess?) and the gases are escaping past the gasket. I figured this out by letting the car run until the chirping stopped, and sprayed the suspected area with water. The water cooled the gasket enough for it to contract and the chirping began again. I hope I don't sound too stupid, but this solves 2 questions at once. 1. what the hell that noise was 2. why the cabin smells like exhaust when I accelerate. I feel much better to know that nothing is being ground down inside the engine.

**Naaman** · 09-06-2016, 11:26 PM

Glad you solved it. So just get some new hardware? Or will you need a new gasket, too?

***SMWS6TA*** · 09-07-2016, 04:25 AM

no kidding. Sometimes it's nice to have an easy win.

**dethinboots** · 09-07-2016, 06:51 PM

New heads go on in a little while. I don't really feel up to the task of extracting the broken bolt in my head if I don't have to. New gaskets and bolts when the trickflows go on. And yes, sometimes simplicity is one of life rare gifts.

***SMWS6TA*** · 09-08-2016, 07:36 AM

Wouldn't either if I had new heads. Glad it was something easy.

MAKE SURE YOU CHECK EVERY HOLE FOR LIQUID. They need to be 100% dry or you'll crack your block.

You may be able to sale your old heads..

**dethinboots** · 09-09-2016, 05:54 PM

please elaborate on your warning. I don't want a cracked block, but I don't know what your referring to.

***SMWS6TA*** · 09-09-2016, 09:45 PM

Once you pull the heads there is always some coolant that gets into the lower head bolt holes. You will need to dry them by any means.

I hit it with a blast from an air hose, then I cut a bunch of paper towel squares and using one of those pick up tools that grab stuff I put a square on the end and insert in the holes, keep doing it till they are dry. Long q tips help too. I made mine on using those long wooden sticks for cooking kabobs taping q tips to them. I used a ton.

It will take you longer to make sure the holes are clean then it does to do the swap of heads.

Check every head bolt hole. Always!! Don't forget to swap over your coolant temp sensor and plugs onto the new heads.