a weird sewing machine sound from motor. I was surprised to find out the IC pump was covered under warranty. Anyways, the main reason I took it it was the sound my engine makes sometimes. I heard it a few months back, I was parking my car and it sounded like someone dumped quarters into the engine, very loud. I assumed coupler so I replaced that. Then a few weeks later it does it again. Noticed it was only at idle, and after the car gets hot, sits for 20-30 mins, then I take off again. Well I assuimed it was the timing chain tensioner, and since I only had a month of powertrain warranty left, I better get it in.

Dealer couldn't duplicate the noise, and they said GM wouldnt let them just replace parts like that. The IC pump was covered on the power train warranty though. GM price on the pump was $404.

So I got a new pump, still not sure what made that noise, and the dealer didn't have a problem working on my State 3 Cobalt.

 

its the timing chain for sure.. heard its a easy fix and they have a how to on here somewhere

 

Cam chain tensioner needs replacing would be my guess.

 

Very easy with the new design ones, turn off car, unbolt tensioner, throw it out, bolt the new one in, turn car on, go

 

Careful, a few weeks ago I read a post about a guy who did that
and "throw it out" his toming chain jumped a tooth, and he bent
every intake valve

 

Wasn't the new design one then

Those instructions came straight from John powell

New ones are run on oil pressure, no springs to set

 

Are there any other instructions? I don't really want to screw something up because I plan on selling my car in a month or so.