1991 GMC Sierra knocking

1991 GMC SIERRA
163,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
KJEFF1990
  • MEMBER
  • 1 POST
my engine is making a knocking noise, which sounds like it is coming from underneath. it only happens when the engine is hot. it knocks while going or ideling. but knocks faster when i push the gas. is it the lifters or somthing else.
Oct 14, 2009 at 6:59 PM
Advertisement
Avatar
BIG_JAY
  • CERTIFIED EXPERT
  • 121 POSTS
Sounds like you have a rod knock. In neutral if u bring it up to about 2800-3000 rpm it will be real loud. The only problem with doing this is there is a chance you could blow your engine. If u need the truck to last put some 50 weight oil in it and take it very easy and you may get a few more miles out of it before it goes.
Oct 14, 2009 at 7:08 PM