Anyone have any idea what this transmission whine is?

[tcfila]

Try it with the a/c blower off. I had one that everytime I accelerated it made the blower motor whine. This happened shortly after I got mine. That was roughly 85k miles ago. Its starting to do it again...

[bmrboi2]

I have a similar whine with the AC on when accelerating. Just popped up this summer. I rolled my eyes when I made the direct connection to having the AC on. Im thinking its the AC Compressor.

[redwoods22]

I'm thinking its the alternator. Have any decent mechanic listen to the engine. On the plus side your issue is consistent and easily reproducible. If it were me I'd walk into the dealer I bought the thing at and tell them to send a master tech out to the parking lot and take 3 seconds to listen to the engine and no I'm not paying a $160 diagnostic fee. You should also get the details on the recall work done on the pulley -- the dealer that did the work will have it. I'd be suspicious that they screwed something up during the recall work.. good luck

[WWONG]

Originally Posted by redwoods22

I'm thinking its the alternator. Have any decent mechanic listen to the engine. On the plus side your issue is consistent and easily reproducible. If it were me I'd walk into the dealer I bought the thing at and tell them to send a master tech out to the parking lot and take 3 seconds to listen to the engine and no I'm not paying a $160 diagnostic fee. You should also get the details on the recall work done on the pulley -- the dealer that did the work will have it. I'd be suspicious that they screwed something up during the recall work.. good luck

I think you're right. So I tried listening with the hood open to see if it's one of the pulleys and the sound seems to be coming from the driver side (where the alternator is). I drove the car today and hear sometimes a faint noise as if plastic is slapping something repeatedly (but it's not) so I'm leaning very heavily towards the alternator. I'll see if BMW will cover this under goodwill warranty in two weeks

[WWONG]

UPDATE: I went to the dealership to get it diagnosed for $160. They gave me a loaner for a week so I will count it as a rental cost

The result was a failing idler pulley. They wanted $1,000. I said no... I'd rather use the money on some new tires and a vacation. I bought a new pulley from their parts dept. for $55 and installed it myself. Took me 6 hours because this was my first time working on this car so I wanted to be careful, there was a lack of DIY on the Internet (not many people have the diesel apparently), and I am an idiot in general. Thank goodness the fan in front is electric and is technically only held on by two tabs (as opposed to my father's old E39 which is connected to the engine).

Now the whine's gone! Wheeee!

[ryan5034]

Curious WWONG did the noise change with AC on / off. I have a similar noise that changes in volume with AC off but don't entirely go away. Wondering if it might be the same.

[WWONG]

Originally Posted by ryan5034

Curious WWONG did the noise change with AC on / off. I have a similar noise that changes in volume with AC off but don't entirely go away. Wondering if it might be the same.

No it did not. The idler pulley has nothing to do with the AC. Its function is... well, just spinning around with the belt. Sounds like you might have a problem with your AC fan.

[ryan5034]

Thanks for the response. After reading some more of the previous posts I think I'll wait another month and just cut the AC belt to see what happens.

[Pooslet]

Hi WWONG, I am about to undertake the same repair on my 2011 35d for the same whine, plus my X5 has 81,000 miles on the original belts & idler pulleys and is time for some preventative maintenance. Did you approach your pulley swap from the bottom or did you manage to reach it from the top? Doesn't seem to be much room up top and would like to know if it's possible from below. I've worked on cars for years now, including 6 different BMWs but don't want to get started only to find out I can't reach everything. Thanks in advance.