o6 gmc canyon engine knocking

echoman · Jan 22, 2012

My wifes canyon with a inline 5cyl engine with 116000 miles ,has a knocking sound at the front of the moter.Its only at idle as soon as you start to rev it up it goes away.If it was a v8 I would say its a timing chain,but Iam no sure if it has timing chain or a belt.Any suggestions would be helpful thanks

Diamondpilot · Jan 23, 2012

Not sure but my mechanic has replaced two of these motors in the last 4 month. One on the truck and one on a SUV. Weird setup with the front drive shaft going through the oil pan.

Chris

Soundguy · Jan 23, 2012

any difference with different fuel grades?

soundguy

echoman · Jan 23, 2012

Soundguy,not a fuel pinging noise. thanks

deerefan · Jan 23, 2012

Soundguy said:
any difference with different fuel grades?

soundguy

I am thinking along the lines of detonation or valve train noise. A rod knock would continue thru the rpm band. The lifter in this motor, I am assuming, are hydraulic, maybe one is not "primed" enough at idle but pick ups lube as acceleration is applied.

s219 · Jan 23, 2012

Does this have a timing belt inside a cover? When slack, those have the exact symptoms you describe. So the problem could either be the belt or the tensioner (assuming the vehicle has a timing belt, that is).

deerefan · Jan 23, 2012

s219 said:
Does this have a timing belt inside a cover? When slack, those have the exact symptoms you describe. So the problem could either be the belt or the tensioner (assuming the vehicle has a timing belt, that is).

It is a chain, not a belt.

Stimw · Jan 23, 2012

Check idler pulley on serpentine belt.
I bought a Chevy Van CHEAP that sounded like a rod knock and I found the pulley bad.

timswi · Jan 23, 2012

Stimw said:
Check idler pulley on serpentine belt.
I bought a Chevy Van CHEAP that sounded like a rod knock and I found the pulley bad.

That'd be my first check too..They tend to quiet down when the RPM's come up.

Easy, cheap fix.

echoman · Jan 25, 2012

Thanks for all of the repliys I would have bet a $100 that it was a timing chain,but I would have lost.water pump ,fan clutch,and while it was in the shop,new idler pulleyand belt.$600and change.