eebasist wrote: Mind if I ask how much you shelled out for the Z3? I'm looking at post facelift (2000+) Z3s right now.
Maybe your question should be "Since this one is annoying you so much, I am sure you wouldn't mind if I gave you $xx to take it off your hands"
You mentioned that when you had it on the lift you ran it through 1st and 2nd, and were unable to reproduce the noise. I wonder if applying the brake and throttle at the same time would load the bearing enough to make the noise while on the lift.
Speaking of "make the noise", I gotta check and see if there's a new project Binky episode coming out soon.
Perhaps a set of Chassis Ears would help? Instead of replacing pricey parts.
Chassis ears on Amazon
They are fairly fragile as the reviews state, but they can really help pinpoint impossible noises. A bit of a pain to set up and route the wires away from moving parts before driving, but if you're stuck they're a big help.
tuna55 wrote:eebasist wrote: Mind if I ask how much you shelled out for the Z3? I'm looking at post facelift (2000+) Z3s right now.Maybe your question should be "Since this one is annoying you so much, I am sure you wouldn't mind if I gave you $xx to take it off your hands"
I have to sell my 2001 MR2 Spyder 1st...I spent the last few months dropping a new motor in it
Woody -- If an E36 drive shaft (1994 325is) will fit your Z3, and you're in the DistMarVa area, I have a good used one sitting in my garage that you can have, complete with the center bearing and joints. I don't have any use for it now, since I'm running a one-piece Ford driveshaft in that car.
Smoking gun! As an aside, I find that many of the fasteners on BMWs are much looser torque specs than the Japanese stuff I used to work on.
At least the whole car will be new by the time you're finished. 
How many miles have you put on this thing? Maybe you just need to take it out and flog it mercilessly?
Woody wrote: Rats! Still making the noise... Next suspect is a bad DISA valve (intake manifold actuator). Maybe I can have a new one in my hands by Tuesday. At least it looks easy to change. https://www.youtube.com/watch?v=_Ri68uuK4R0
DISA valve usaully makes a rattling noise when failing. If the seal is bad it might make a whistling noise, but that can be diagnosed with a spray of carb cleaner around the seal with the engine running.
The DISA valves aren't cheap either. I strongly recommend removing the existing one for inspection before buying a replacement. The broken shaft will be obvious once you have it in your hands. There are also aftermarket repair kits for the M54 DISA valves that are not only cheaper than replacement, they are stronger than a new plastic one.
always a good feeling to track down an issue and deal with it. Not to mention catching up on the deferred stuff.
You cant do this to us!!!!
What was it??????
Was it the hose?
Nice work Woody! I know that was a good feeling when the noise was finally gone.
Nice. Glad it wasn't actually the diff.
Congrats!
I'd been aggravated with noise on my Z4 for more than a year that I thought was just a bad tire-- definitely speed related. As it got worse, becoming more noticeably changing weight transfer with throttle/brake and going away if the car was loaded up for a right turn, found out it was both passenger side wheel bearings, though the rear wasn't really noticeable until the front was replaced. I would have expected the driver's sides as most road courses I've been to have more right turns than left, and that's the side I've worn out ball joints and strut bearings in the past.
Now that it's fixed, it's like a new car again, even just having turned over 98K miles!
Enjoy!
Congrats man! Better to have this adventure when the car is still "new" to you. Annoying stuff like this is a lot less charming later on. Well done!
Woody,
I have a 1994 325is that has a loopy idle, will not pass smog here in California, I wish you were available to work this one out. Congratulations on the "fix".
David
Glad you finally found it Woody. I'd post that thing on my wall to remind me just how much I like working on my BMW.
https://grassrootsmotorsports.com/forum/grm/bmw-mystery-noise/107019/page3/
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