I have a 94 z28 with 160,000 miles on it. Runs good but a new noise has come up in the valve train. It is not there when the engine is cold, then gets louder as the engine hits operating temp and is very noticable and loud. It is more squeal than ticking or tapping but it definitly is realted to rpm, and sounds like a lack of lubrication somewhere. Recent oil change did not change anything. No leaks of anykind and good oil pressure according to gage One suggestion is timing chain is it is loose enough would it make noise or rub on the housing. Any thoughts would be appreciated.

 

Under the valve covers??? In front of the engine??? Right/left side??? A squeal is usually associated with the belt, tensioner, or a pulley bearing...

 

Thanks n2ceptor. Hard to tell if front or back or left or right, some people say front some say back ones that have heard it. Not the belt itself and consistant with a bearing sound but maybe. How can i check and see if it is a bad bearing?

 

+++100 on the belt

 

Ok it is %100 not the belt. I have had a couple other mechanics listen they say rocker or lifter i am going to pull the covers and check the rockers first. My next question is can the lifters be replaced with only pulling the intake or do the heads have to be removed?