Hello,
I have a 2008 Cobalt LT, 212k miles, 2.2Ecotec. Hoping someone can help me out with this noise that started a couple weeks ago. Gets louder as revs increase, so far my mechanic has first replaced the belt & automatic tensioner pulley, noise quieted down for 2 days then came back just as loud. Now the harmonic balancer has also been replaced (was wobbling.) and still the same noise! Except it quieted down a little bit, again. I've put a couple thousand miles on this car since the noise started and it hasn't gotten much worse, gives me no issues driving it & idles/starts perfectly fine. No check engine light, scanned it and no codes. Could it be the alternator starting to go? One thing to note, my A/C stopped working about a week before this noise came. No idea if that has anything to do with it, but figured I should mention it.
Link to video, sorry it's pretty quiet. Crappy phone recording. https://youtu.be/UZCE_VfHHKs
it could very well be the ac compressor
I guess I'll take it out in the morning and remove the A/C fuse and see what happens. If not, gonna go buy a stethoscope and see exactly where it's coming from because it's driving me crazy!
fuse may not help if the mechanical clutch is malfunctioning
Ah, I see. Is there anyway to check that then without having to remove/replace it? Thanks for your help!
Will take a look at the video here in a couple minutes, I'm hoping that maybe I can just disconnect power or something, I'll worry about replacing it here in summer just need a quick fix to stop the noise. Will report back in the morning!
The video is for a worn pully which you asked for. in that case, disconnecting power may not help because it's always spinning.
Thanks for the reply, just went and listened with a stethoscope and confirmed it is indeed the A/C compressor. I actually already have the shorter belt that was bought by mistake when I went to replace the tensioner & harmonic balancer. Guess I don't need to return it now, gonna get it on tomorrow
Checking if it's something on the fan belt circuit is easy enough. Take the belt off and run the engine for a couple seconds. If the noise goes away, it's something on the belt circuit. Pull on the pullies and spin them, feeling for looseness, binding or grinding. Replace whatever feels worn. If it's the A/C compressor, you can buy a shorter belt that deletes the compressor from the circuit until you decide if you want to fix it.
Thanks for the reply, just went and listened with a stethoscope and confirmed it is indeed the A/C compressor. I actually already have the shorter belt that was bought by mistake when I went to replace the tensioner & harmonic balancer. Guess I don't need to return it now, gonna get it on tomorrow
Didn’t your mechanic know about the malfunctioning AC?
Honestly, no. It went out a week or so before but there was no noise all that time, and I guess it just slipped my mind to mention it. I don't mind that we did the new pulleys and belt though cause they both would of needed it soon anyways. (were wobbling, starting to go bad.)
Fair enough then.
Just a quick update, got the new belt on today bypassing the AC/pulley and quiet as can be now!