hi guys, i have a potential problem (again). So today i started noticing this whistling sound coming from the engine bay. Its engine speed related, not load or vehicle speed. I haven't noticed it before, so i'm thinking it might be bad. Anybody got any suggestions of what i should check? I looked around the engine bay with the car idling, and i couldn't pinpoint an exact location for it. Thanks for the help.

 

is it like an air leak whistle? check the seal on the airbox really well. Or unlatch it when idleing (in park) and see if the noise changes.

if its more of a whine, it might be the alternator bearings. or any other pully for that matter. remove the belt with the engine cold, and let it run just a short while with it off. If the noise stops, then its most likely a pully.

Next, shut the car off and spin all the pully's by hand and see if you can replicate the noise. might also just need a new belt.

could also be the power steering, check the fluid and then see if the noise changes when you "saw" the wheel back and forth while stopped. (engine running, obviously).

auto or manual trans?

 

its a whine i guess. very close to what i hear prochargers sounding like (i checked, my engine didnt grow one )

ill do the belt thing tomorrow, that was my first thought. i didnt have any time to look into it today, because i noticed it right after draining my battery with the radio while taking the dealer decal off. had to bump start it, and then the noise bothered me while i drove it around to recharge the battery (yes, i could have let it idle, but wheres the fun in that?) its a manual trans, btw, and the noise is there even with the clutch in, so it cant be the transmission.

 

update: took off the front belt this morning, and the noise seemed to be gone. considering other engine noise, and the fact that i didnt want to rev it too much without a running water pump, i cant be sure that it was gone, but i think so. all the accessories turned fine by hand, but the tensioner pulley seemed a bit loose, and the other idler took a bit more force to turn than i expected. belt looks fine as far as i can tell, but there is black residue on all pulleys, i assume it indicates a worn belt, but it could be from an older one that was replaced years ago.

 

Sometimes charging a completely drained battery with a jump and driving the car is bad for them. They dont like to go "full-Field" for an extended period of time. Maybe it was just over working the Alternator. Dont do that too often tho, or it may kill it.

Or its the belt. if it comes back, replace it. and if it comes back again, drive it till its obvious which pully it is lol.

 

i dont plan to drain the battery. i dont think it would have happened at all if the dealer had actually put in a new one like he said. anyway, i already bought a new belt, which i will install tomorrow, and i want to replace the tensioner pulley asap. anybody know if i can take the pulley/bearing off myself? it would save me around $30

 

just an update, i swapped in a new belt this morning, and the noise is still there. i strongly suspect the tensioner pulley. I will be replacing that as soon as i manage to take the pulley off the tensioner part. Anybody have any advice?

 

from what you mention, the fact that one of idlers was perceptively harder to turn may be a clue that the bearing in it is going bad. a whine is typically friction related which would be definitely what a bad bearing will do before sounding more and more macabre :-)
i hope this helps

 

thats a great point. however, the loose bearing has quite a bit of play, and makes an almost rattling noise even when spun by hand. whether its the cause of the whine or not, it needs to be replaced. it looks a lot easier to replace than the other idler, so id prefer to get this one first, and if it turns out to be the problem, i save myself some work.

 

i have this same noise he is talking about and found it funny that you mentioned power steering fluid because i think one of the main things that triggered/triggers this noise to start is when i turn the wheel hard. from then on the noise is there almost sounding like a vacuum leak and gets louder as rpms get higher, even as im driving straight or sitting still...fluid level looks good, should i try changing the fluid?

 

i had a similar sound..except mine sounded more like a supercharger.. check the tensioner..when mine was making the sound the tensioner was bad and not holding the belt tight enough.

 

the tensioner is definitely tight. replaced the pulley on it. the noise is definitely less noticeable, and none of the pulleys made funny noises when spun by hand, so my bet is on the A/C tensioner or idler. gonna have to check that out some time. thanks for the suggestion tho