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Discussion Starter · #1 ·
I have an 02' 745i. About a year and a half ago it started making squeaking noises which were in accordance with the RPM's. When I started the car it would squeak sometimes for a couple seconds and sometimes for a minute or two. When the squeaking became more frequent I took it to my BMW tech who works out of his house (also is employed at the local dealership). He could not find an obvious problem with it but replaced the drive belt and the tensioner and the sound went away for about 3 or so months. The sound then slowly started to come back but was infrequent and only lasted a short amount of time. This past week after it had been sitting for about 2 weeks it started to do it again and this time its much more violent and doesn't go away. WHen I start the car it sounds like a constant screach for about 2 minutes and then wavers to an eventual stop and goes away but only when it's at idle (500 RPM). When I press the gas pedal it comes back (throughout 700-2700 RPM) and goes according to the RPM's(the higher the RPM the faster it chirps).
When I have it in gear and am driving it makes the loud constant screech when I'm turning the wheel and gets progressively louder the farther I turn it. It does not matter if I'm in drive or reverse the noise occurs in both. When I'm driving straight however, the sound seems to fade and sometimes go away. It also acts up with the change in temperature and weather as far as being louder and more constant. When It's wet out it seems a little more constant. It can be roaring loud as anything and then I spray a little WD-40 on the belt and the noise instantly goes away. But is back in a minute. I have checked all the pulleys and they spin with correct resistance without wobble and the belt is properly aligned with all the pulleys. They power steering pulley spins with more resistance than the others and when I spin it it doesn't stay smooth like the alternator does. When I'm spinning it i can feel spots of higher resistance Is this normal? I also swapped out the PS fluid and it's full to just under MAX. What could the noise be?
 

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I'd have the whole power steering system checked out. What happened to a friend of mine was he had the same issue and the tech's found that the pump was fine, but the rack and pinion had an issue. Warranty replaced the whole rack and pinion and the problem was solved!
 

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Discussion Starter · #4 ·
could it be the rack and pinion when the noise is coming from the belt and pulleys? Like I said when i spray the slightest amount of WD-40 on the belt the noise instantly and temporarily goes away.
 

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I had exact same problem. Your pulleys are glazed so the belt is slipping. Pull your belt off and spray brake cleaner on just the pulleys. Not the back of them, bit just the pulleys and scrub them with a brillo pad or wire brush. And wipe them down with a towel when down and then put belt back on. Problem should be fixed.
 

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Power steering pulley is at the bottom so its easier for contaminants to get on it. The extra load from the pump when you turn would cause a slip if oil or coolant or anything else got on that pulley and was never removed.
And stop spraying wd40 on it, you are only making it worse lol.
 

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Discussion Starter · #7 · (Edited)
I recently took the belt off and did exactly that except without the brake cleaner. I took the PS pulley off and scrubbed it down and did the best I could for the rest of them. I might need a new belt though cause it was slipping for a while and might have ruined it. I havn't put any WD-40 or anything else on it since
 

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Get a new belt. Make sure its conti 6pk1555 and nothing else. Clean the pulleys again when u get ready to put on new belt. They should look clean between the grooves when you are done. Good luck. Make sure you get the brake cleaner also.
 

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All three pulleys should spin with a fair amount of resistance.

They should not spin more than about 1 full revolution by hand or they are shot.
I had exactly the same issue and 2 out of 3 of my pulleys were bad, i changed all three and noise has never come back.
Cheap fix as well..:thumbup:
 
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