1992 Chevy Caprice noise under valve cover when engine is c

CGLOVER67

MEMBER
1992 CHEVROLET CAPRICE
V8
2WD
AUTOMATIC
150,000 MILES

I have 92 chevy caprice with 150.000 miles. When I first start the car there are humming noises from the both valve covers. It stops after about 15 minutes after the car is warmed up. After it stops the engine sounds perfect. Some shops say it can be the oil pump. Others say it can be the lifters. I dontknow which is right or what it can be.

Thursday, January 22nd, 2009 AT 5:27 PM

1 Reply

PEAR69

MECHANIC
1,482 POSTS

It could be either of the two. A failing oil pump will be associated with low oil or high oil pressure, and a distinctive connecting rod knock as well as a lifter knock. Any mechanic will know this sound when he or she hears it. This knock usually does not go away.
A lifter knock usually goes away after the engine warms up, or shortly after a cold start. Except in the case of a bad lifter - of course.
I would say it is a lifter noise.

Was this

answer

helpful?

Yes

No

Thursday, January 22nd, 2009 AT 8:46 PM