Hi guys, I'm new here. I have a 2007 HHR with a 2.2 engine manual transmission 170k miles. I have a moderate knocking noise starting at around 2000 RPM. In my experience, early stage rod knocks are more audible when the excellerator is released abruptly. Any ideas?

 

Welcome to the site, it could be a couple of thinks the upper engine mount can be worn out.
Loose timing chain or tensioner

 

Piston wrist pins do that.
A bearing knock is when you accelerate.
Hope that helps.
I wish these cars had an oil pressure gauge from the factory.

 

Amen, and a volt meter!

 

Welcome & I agree w/Cat Man, rod knock is most audible when accelerating like under load.

Agree on oil & volt gauges would have been nice factory equipment.

 

Well dang, I sure hope it's not a rod knock. Is that common on the 2.2 engine?

 

No,

and I see no reason for either gauge.

I have driven cars with no oil but normal oil pressure, and what does oil pressure have to do with rod knock?. I've never seen a voltmeter factory installed, ammeters are useless with alternators.

As bad as a code readout on the dash; too much information is bad.

 

Sorry Don your not a mechanic. Don't take offence to my statement.
"what does oil pressure have to do with rod knock?"
Let's see, no pressure bearing go dry, knock.

 

They knock because they wore out, maybe because there was no oil; not because there was no pressure. The oil disappeared a week before, and as stated I have driven cars that showed normal pressure with nothing in the pan.

Oil pressure in modern cars doesn't tell you anything except that the pump is still functioning.

I would rather have an oil level gauge.

 

If there is no oil pressure, the oil does not get pumped thru the crank to feed the rods & mains, plus the top end.