o6 gmc canyon engine knocking

[echoman]

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]

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]

any difference with different fuel grades?

soundguy

 

[echoman]

Soundguy,not a fuel pinging noise. thanks

 

[deerefan]

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]

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]

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]

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]

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]

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.