New sounds in old cars are always the root of adventure - a couple of days ago I noticed a new sound coming from my HHR .... imagine the thrill.

Going up a hill at part throttle (stuck behind a dump truck) I get a "whirring" sound (engine, not road speed dependent) - IF (and only if) I get on the gas the noise goes away.

I was thinking a knackered cam chain tensioner but it's quiet at idle and quiet at full throttle - if experience has shown me anything it's that the cam chain makes a racket at idle and a bloody awful racket at full wellie!

The slush box works fine - nice crisp shifts (both up and down), the CV's and wheel bearings are fresh as of April 2013, the AC compressor sounds like death warmed over when it's on BUT on or off the "noise remains the same" ....

No vacuum leaks that can be detected with starter spray (so I presume there are none as the thing didn't catch fire) - I can try to catch the noise on my cell and post it but it's rather subtle (one of those sounds you hear because you're expecting to - not because it nails you in the side of the head).

Only CEL being thrown indicates I've got a bad O2 sensor - but that wouldn't make it wheeze like an old man during a stress test ....

Thoughts, suggestions (polite and otherwise) are invited -

Cheers

Steve

 

By golly, you might have found a new funky noise. which engine ? If it's the 2.0 it could be the turbo they make a few funky sounds at various rpms.

 

Really sorry to hear this. I can look into your concern for you and see what options you may have available. Just private message me your name, address, vehicle identification number, and current mileage.

Thank you,

Jessica L.
Chevrolet Customer Care

 

If you mention a cell code, please post the CEL code - it may well be related to a cracked flex pipe, rather than the O2 sensor. A cracked flex pipe can make some unusual noises at various times, and can affect the fuel mixture.

 

FLEX PIPE or some other hole around the cat, as I think I tried to tell you in the HO2 sensor thread.

 

It's not a turbo - it's a plain jane 2006 - I'll read the codes this weekend and post - and I'll try to record the sound and post it - only happens at part throttle, typically on an uphill - car runs fine - MPG is hovering around 28 (with a heavy right foot that ain't bad at all!) - the last code I pulled had to do with a light bulb being burned out - I replaced the bulb and re-set the code - we'll see what the code du jour is ....

Cheers

Steve

 

What's turbo got to do with the flex pipe? That is the accordion looking piece between the exhaust header and the cat. Incredibly well documented on this forum. Use the search tool "flex pipe".

I guess I just speak a different tongue, I'm out. again.

 

The sound can also be made when there's a bit of plastic bottle lodged in the alternator cooling fans - think playing card in the spokes of a bicycle wheel (see the movie "Dennis the Menace" for both visual and auditory reference) - removed errant bit of a green plastic bottle (mountain dew? 7 up? Ginger ale?) - the noise is now gone.

My Turbo comment was because someone else had suggested a turbo issue - I've had a number of turbo charged vehicles - this COULD have been the sound of a waste-gate actuator (vacuum based) with a leak in a diaphragm - but it wasn't.

Thanks for the flex pipe tip - should a similar noise come around again that'll be the second place I look (after checking for errant soda bottle jetsum partially ingested into the accessory drives!)

cheers

Steve

 

If its the flex-pipe you better drive with the windows down until you get it replaced as a lot of the exhaust will enter the cabin.