Here's a tough one for our 1998 M3 I have a medium pitch squeal to rattle noise coming from the right front of the engine compartment at idle. Thought it was belts ( Thanks to all for the help on the tensioner ) and changed them. Next I went for the alternator but it spins free with no noise. Next found the ideler pully rattled so I changed that. Last thing in that area is the power steering pump and the noise seems to come from that lower area. Anybody had a pump going bad and rattling??? Thanks Bud
There is a idler pulley and a (stationary) deflector pulley on that belt. Did you replace both? Have you tried running the engine with the belt removed to verify the problem?
Jeron I did change out the stationary idler pully as it was making some noise. The tensioner pully was fine. I'll pull the belt today and try it. Thanks Bud
Have you tried listening to things with an automotive stethescope? They are cheap at the auto parts store. Do this at your own peril, though, because if you slip with the probe, it hits the belt, but it is the fastest way to tell what is making the noise. If you have to check a bearing, put it against the closest stationary part that is bolted solidly to the bearing, like the center bolt or the bracket that holds it.
Thanks Guys I found the noise last night. It did turn out to be the tensioner pulley. New ones on the way Bud
I have the same issue on my wifes M3 its driving me crazy I' have to let it be ill after the holidays though. hope it wont hurt nothing letting it be. I seems to go away once we have drove the car for about 20min but on fisrt start it squeals like a son of a bee...
Don't let it go too long without knowing the problem, those things throw tensioner pulleys! Even happened to my little sister's car and I think it took out the fan.
DIY tip on this. I am not sure if the M3 engine is different with the idler pulley and tensioner, but on my M44 engine in my 1997 318ti I ended up replacing the idler pulley / tensioner assembly from the bottom. Once I got the tension off the old belt and removed it I noticed that the power steering pump pulley is blocking the bottom tensioner mounting bolt. After some wrestling from the top of the engine bay it occurred to me that there was more room to get at these parts from under the car. I used a long flat head screw driver to wedge 2 of the 4 bolts on the power steering pulley so I could loosen the other bolts (keeping it from turning). Don't back them all the way out so you can repeat this process until all 4 are loose. Then I had to slightly heat the aluminum pulley with a small propane torch (used for soldering pipes). Once heated, it popped off with one strike of a rubber mallet. Then the 2 allen cap screws holding the tensioner were easy to get at. Another tip, the replacement tensioner will have a "L" shaped pin holding the unit back in the un-tensioned position. Leave the pin in until you get everything bolted back together and your belt is routed. Then take some channel locks and pull the pin out. It will snap and release the spring pressure. Took me about 1hr & 30min to complete. Some of that time was due to a beer break. ~Mike R~
Good tips, but it is completely different on the M3. One would hope that Devilsown took a look at the car by now, since it was making noise 9 months ago.
