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prynce_qt
10-14-2005, 12:01 PM
I'm having this high pitch sound coming out of my engine, the more I give it gas the more it sounds. It's not overly loud but its there in the background. I notice after my last oil change. What can it possible be? Is there something that needs to be replaced around 150,000km? Sounds to me like a bearing that needs to be oiled but I'm completely clueless. Can it be the oil? I got the car in Feb and always put synthetic oil in it, my dad did the last change for me and put conventional 10-30w. He thinks oil is oil but that's another story. Throw out some possible answers that can cause the noise. thanks.

Understated
10-14-2005, 12:09 PM
hm...are you sure some1 din install a supercharger in there without telling you :D

honestly that sounds really wierd...no clue what it might be.....have u tried popping hte hood and seein where exactly the whining is coming from as you press the gas :confused:

Cosmic 325i
10-14-2005, 12:13 PM
maybe its the power steering fluid thats low

prynce_qt
10-14-2005, 12:32 PM
I'll check the fluids later, but can low fluid actually cause a sound? I tried listening to the sound in the engine bay but its very hard to tell where its coming from.

Cosmic 325i
10-14-2005, 12:38 PM
yeah it can-when my fluid was low my power steering pump made a squealing noise-especially when turning the wheel. could also be a vacuum leak?

paul
10-14-2005, 03:03 PM
no it's water pump going mine did the samething change it now before u get suck

SebSter
10-14-2005, 03:26 PM
heres a longshot, do you have an aftermarket sound system? or even head unit installed?

a poor install with bad grounds can cause an 'alternator whine' which is a progressive high pitched whine that grows with the speed of the engine.

chromius
10-14-2005, 03:48 PM
it could be any pully driven accesories.

Alternator, Waterpump, Power steering, A/C. Timing belt.

When was the last time you changed your timing belt and tensioner? It could be the tensioner.

It could also be something as simple as a loose belt.

Does the sound change when you push your clutch pedal in? If it does it could be the input shaft bearings on the Transmission.

Those are just a few of the things to check.

I would start by pulling belts off non-essential components...ie, A/C, Power steering. Make notes of changes to the sound depending on condition, ie. operating temp, ambiant temp, engine speed, under load noises.

prynce_qt
10-14-2005, 05:12 PM
it could be any pully driven accesories.

Alternator, Waterpump, Power steering, A/C. Timing belt.

When was the last time you changed your timing belt and tensioner? It could be the tensioner.

It could also be something as simple as a loose belt.

Does the sound change when you push your clutch pedal in? If it does it could be the input shaft bearings on the Transmission.

Those are just a few of the things to check.

I would start by pulling belts off non-essential components...ie, A/C, Power steering. Make notes of changes to the sound depending on condition, ie. operating temp, ambiant temp, engine speed, under load noises.

off my 318 it looks like its coming off the engine itself or around there. i have no clue what is what inside an engine to even start pulling off belts. also i thought my car doesn't have a timing belt so it doesn't need to be changed.

BMW_7
10-14-2005, 05:19 PM
dude maybe you got DASC :p

chromius
10-14-2005, 09:49 PM
off my 318 it looks like its coming off the engine itself or around there. i have no clue what is what inside an engine to even start pulling off belts. also i thought my car doesn't have a timing belt so it doesn't need to be changed.

sorry, my bad...I forgot you guys had timing chains.

Well the other option, aside from pulling off belts, is to go and buy a mechanics stethescope, and start probing around to find the sound. Just be really carefull around the belts and pully's, you don't want to get caught up.

What it really comes down to, is you have to pinpoint where the sound is comming from, because there is no point in replacing some expensive parts that "might" be the problem. Otherwise you might end up spending a lot of money and still be stuck at square one.

If all else fails, take it to a mechanic, and he should be able to tell you what the sound is.

Manimillion
10-14-2005, 10:07 PM
You might have a bird stuck in your intake :P