XSeries-forum

I just completed a 1500 mile drive from Florida to Massachusetts in my 2012 X5 3.5 that has 130,000 miles on the clock. I spread it out to three days and two overnights with legs of approximately 500 miles each. Towards the end of each leg the car developed a high pitch chirping sound that appeared to come from the front of the engine. The following observations were made:
1. The noise started towards the end of each leg and not at start up or after a cool down, an overnight or extended rest.
2. The chirping does not occur under a load (accelerating) or going up-hill. It would come on during descents, at rest idling or on the flats without the gas on.
3. It is difficult to determine where the sound is coming from but clearly from the front of the engine.
4. AC on/off makes no difference.
5. It was a very hot drive with the average temperature in the mid 90s F. There was one rain shower during which the chirping persisted.
6. I spoke with a tech from the local BMW dealership but he needed to hear the sound and unfortunately it is not available on demand.
7. The fan belt and pulley were replaced approximately one year or 6K miles ago.
8. Since my arrival I have been driving around locally without any noise. I assume I have not generated sufficient heat or tension yet to start it.

Those are the key points. Any ideas are appreciated. Thanks.

Belt would be the first thing i would change.
I recently fitted a new one on my 320d and that did this so changed it again and all ok now.
Both belts where good brands Dayco was the first and replaced with Gates.

Thank you!

Nice to see a "Thankyou" to a question.

Lez

Yeah, you can come again any time

A thanks is nice but reporting back with the fix is better i think.
Well it will help others.

I just had the belt, pulley and idler replaced for $460 here in MA. I will be driving to Cape Cod in a few days and will see if this corrects the issue. Either way I will report back.

Any update on this? nice to see someone from across the pond. Where diesel is not a very popular choice.