A few days ago at start up, a loud clacking noise began from the driver side valve cover area. It is louder than the sometimes heard ticking at start up. The noise goes away slowly until about 3-4 minutes have passed and the engine is warm. Bad lifter? Bad oil Pump? Ideas?

Gordo

 

If it goes away after 3-4 minutes it sounds like a lifter to me.

 

Another forum I checked said maybe the oil pump is bad. What do you think about that?

 

Most likely a lifter. If the exhaust manifold is cracked or had a bad gasket it could be described as a ticking noise and would go away as it heated up. Look to see if any bolts are loose or broken off. If it is a lifter tap find a shop that has the newest BG oil flush (109), I have seen it fix more than 90% of lifter taps.

 

I agree with the "lifter" theory. GM engines have been known to do that from time to time - and the noise always seems to go away when the vehicle warms up after a few miles.

BG is pretty good stuff; at least from what I hear. My 2004 Silverado has had the "BG" service done about 10,000 miles ago and she's still going strong with 84,000+ miles on the clock. I got her used, but plan on keeping this vehicle a long, long time!


P.S. From what I hear, the 5.3L is a darn good engine!