Loud Screeching in 1st and 2nd

[LB2475]

Hello All,

I purchased a 1987 325es a couple of days ago and I'm working my way through the engine. At idle it has a very quiet version of what I described but then in 1st and 2nd gear there is a horrible high pitched screeching coming from the engine bay that goes away at higher rpm's and by 3rd gear it is completely gone. Anyone have any idea what it could be? I was told it could be the alternator belt by one person.

The previous owner tells me he had the transmission checked out and was told it was nothing in there.

Any ideas?

Thanks,
Logan

[dnguyen1963]

Check your belts. Some or all of them are loose.

[LB2475]

Check your belts. Some or all of them are loose.

Thank you much! I'll do it. Would this also make the idle seem a little rough and screechy?

[jlevie]

Screechy yes, rough no.

[LB2475]

Screechy yes, rough no.

It's not rough so much as squeaky. It really does just sound like a belt issue. I'll replace all three this weekend. Any good guides out there for the procedure?

[coldweatherblue]

first, are your a/c and power steering working? If a/c isn't working you can run without a belt until you get it fixed.

notice the mounting points for the alternator, PS pump, and A/C compressor. You will need to loosen the bolts that hold the unit to the engine assembly. typically it's one bolt on the rear bracket and one bolt on the front bracket which is connected to a toothed piece of metal. loosen both bolts.

The assembly should now move side to side. If it doesn't there's another bolt somewhere holding it back. Once you loosen the mounting bolts, use the front bolt on the toothed piece to relax the drive belt. You turn the bolt and it relaxes or tightens the belt. when you have the belt fully relaxed, carefully remove it off the pulley.

Pay attention to the order in which you remove the belts. When you install new belts put the alternator on first, etc.. so the order doesn't get screwed up. Do not force the belt over the pulley. If it will not go on, try loosening the bolts a little more and moving the assembly closer to the engine, push really hard to get it close to the engine then slide the belt on.

May want to look up exact specs for how much play should be in the belts, i'm sure it's around here somewhere. You measure the amount of play in the center of the belt and tighten it to specification.

probably want to pick up one of these if you are new to e30s:

http://www.amazon.com/BMW-E30-Servic.../dp/0837616476

[LB2475]

Wow! Thank you SO much for the in depth reply. I really appreciate it. I do not have an A/C belt on the car at the moment but I just ordered a full belt kit for the car so I'll go ahead and put it on. I read somewhere else that there should be about 1/4-1/2" of play in the belts. I'll do some more searching with a definite number.

Thanks again guys!

[dnguyen1963]

Since you are new to E30, I highly suggest that you have a shop perform a smoke test on the engine. Fix any vacuum leaks that you might find. This will save you a lot of headache down the road.

[LB2475]

How much does that generally cost?

[jlevie]

There are two fasteners that must be loosened to change each belt. The obvious one is where the toothed adjuster is. The less obvious one is the pivot bolt. If you don't loosen the pivot bolt you can tear the teeth off the adjuster.

[dnguyen1963]

$80 - $100 depending on where you live. You can also make one yourself for cheap. There are plenty of DIY out there. You need to plug the intake and exhaust to find small leaks.