Grinding Noise About 15-20 seconds after cold start

Grinding Noise About 15-20 seconds after cold start - Video

I get a grinding noise from my engine approximately 15-20 seconds after start up. Almost like you're holding the key in the ignition to turn the car on too long (I'm not). When I turn the car on, there's a sort of whirring/humming noise (that I don't notice as abnormal other than it disappears after the grind). then that split second grind noise, then the car sounds fine.

It appears to only do it on a cold start (after it's been sitting a few hours at least).

Ideas? Or is this normal? (I know nothing about cars).

'08 Cobalt, btw.

Now with video goodness

DSCN3522 - YouTube It starts right around 23 seconds...it's a little hard to hear, but, it's definitely there...

What engine? 2.0 2.2 or 2.4

2.2, I believe. Video uploaded in first post.

Where does the noise come from? If it sounds like its around your starter, it could be a bad selenoid not contracting after the engine starts. If on the top, have you pulled your valve cover to see if there's anything there? No metal shavings in oil are there?

The noise appears to be coming from the passenger side, near/under/around where the air filter is located (I am really bad at locating noise sources).

As far as shavings in the oil, the oil was changed about 600 miles ago, and looks fine.

how many miles are on it? have you replaced your belt recently at all? did you see if there's any where on that or any pulleys?

53,000 miles. I haven't replaced any belts since I bought the car (I bought the car when it had just under 47K, in Jan 2011). I will try later today to try to see what I can on the belts/pulleys (I don't know anything about cars. I can change my air filter, and that's about it...I do, however, like to have an idea of what's going on when I go to the dealership).

Thanks for your help so far!

Is it still under warranty? I'd bring it to them if it is. It's really hard diagnosing things when you're not actually there... Does it happen when your ac is on? If so, could be a bad ac clutch. Do you throw any codes?

katheek77 said:

I get a grinding noise from my engine approximately 15-20 seconds after start up. Almost like you're holding the key in the ignition to turn the car on too long (I'm not). When I turn the car on, there's a sort of whirring/humming noise (that I don't notice as abnormal other than it disappears after the grind). then that split second grind noise, then the car sounds fine.

It appears to only do it on a cold start (after it's been sitting a few hours at least).

Ideas? Or is this normal? (I know nothing about cars).

'08 Cobalt, btw.

Now with video goodness

DSCN3522 - YouTube It starts right around 23 seconds...it's a little hard to hear, but, it's definitely there...

Click to expand...

Hi Katheek77,

Because I am not a Certified Mechanic I unable to diagnose the problem you are experiencing. If you like, I could schedule a service appointment with your dealership. If so, please private message me your vehicle's VIN#, your address, phone and the dealership you wish to have your vehicle serviced at.

Vanessa,
Chevrolet Customer Service

BankDude said:

Is it still under warranty? I'd bring it to them if it is. It's really hard diagnosing things when you're not actually there... Does it happen when your ac is on? If so, could be a bad ac clutch. Do you throw any codes?

Click to expand...

I thought of the AC, but, have had it off for the past few times that it's been turned on.

It is still under warranty; I made an appointment this morning for next Tuesday.

When I got home from work (I walk, so, car hadn't been turned on), I checked what I could see of the belt and alla that, but didn't notice anything. I very gently pushed/pulled on it to see if there was any slack, but there really wasn't any. I turned the car on for just a few seconds, just to get the belt moving around to a different position. Saw nothing. Turned the car on and watched the belt to see if I noticed anything when it made the noise.

The sucker never made the noise.

So, later tonight, I will turn it on and see if it makes the noise if I don't turn it on for those few seconds.

Is it at all possible that something was even slightly out of kilter and pushing/pulling on the belt got it back inline?