Loud Squealing Noise

My car has less than 6k mi on it and I have noticed on several occasions that when I cold start my car, I hear a loud squealing/screeching noise that sounds a lot like a fan belt slipping. I first heard the noise while creeping along in slow moving traffic, but I was in denial at that point that the hideous noise I was hearing was actually coming from my car. Now after hearing it several times at start up to include this past Sunday, I can say with confidence this despicable noise is in fact emanating from my car.

I plan to take it in to the dealer, but I was curious if any of my fellow "d" owners has encountered a similar issue.

Originally Posted by cssnms

My car has less than 6k mi on it and I have noticed on several occasions that when I cold start my car, I hear a loud squealing/screeching noise that sounds a lot like a fan belt slipping. I first heard the noise while creeping along in slow moving traffic, but I was in denial at that point that the hideous noise I was hearing was actually coming from my car. Now after hearing it several times at start up to include this past Sunday, I can say with confidence this despicable noise is in fact emanating from my car.

I plan to take it in to the dealer, but I was curious if any of my fellow "d" owners has encountered a similar issue.

That's a timely question for me, as just yesterday I was backing out of my garage and heard the distinct screech of, I'm assuming, a slipping belt. It only lasted for a second. I had not driven the car for about a week (just had knee/ACL surgery ) so I rationalized it must have been an isolated issue. I've had the car for 1 yr + 2 days (13k miles) and that was the first squeal I've heard that wasn't from the tires...

If you take it in, let me know if they find anything unusual.

-Graham

Had the same issue on my 2011 335d. Mine occurred if the car sat out in the sun for a period of time and squealed when the A/C kicked in after start-up.
Took it to the dealer and they cleaned "contamination" (oil, grease, dirt) from the belt and re-adjusted the tension. Fixed the problem right away. NO CHARGE!!

15k plus miles on my 2011 D with no squeals other than from tires

Definitely a squeeling fan belt, unless you have a pig farm near you?

Very annoying and usually resolved by a simple tightening of a loose belt.

However, it could also potentially indicate a binding bearing on an idler pulley or A/C compressor wheel.

Sometimes it can occur when the belt is wet or there is high humidity.

Very easy to fix if it is just a loose belt however.

I have noticed that my A/C compressor makes a bit of noise at idle when I first start up with the A/C on. It is good practice to turn your A/C off when you shutdown and then turn it back on after you start of your engine each time to avoid that additional load on the starting motor.

By the way, I have noticed with my new Garmin ECOroute HD device my engine load changes quite a bit when at idle in nuetral vs when in drive, and now with the A/C compressor running it increases even more. It is definitely measurable and noticeable, which means you could impact your fuel economy by changing up a few driving habits.

Originally Posted by Flyingman

By the way, I have noticed with my new Garmin ECOroute HD device my engine load changes quite a bit when at idle in nuetral vs when in drive, and now with the A/C compressor running it increases even more. It is definitely measurable and noticeable, which means you could impact your fuel economy by changing up a few driving habits.

Since the time you mentioned I am making it habit to shift to neutral if I feel stop is >10 secs. In few days I will know how much mileage difference I will see. From my engineering education I feel there is no harm in shifting to neutral so if it helps even a bit I dont mind doing it.

bimmerdiesel,

The lights here in South Florida are timed rather long, so if you catch a red you could be there for a good 2-3 minutes waiting to get your green again.

I'll time a few, and shoot some of the load and air flow data in Nuetral vs idle in drive, plus with and w/o A/C.

I'm sure this is one of the reasons that manual trannys always show lower mpg than automatics, usually by at least one mpg less.

Just remember you have to have foot on the brake to switch back into drive, which has caught me off gaurd a few times.

Also have the intermittent 1-2 sec belt squeal on start up - car is at the dealer today for 13K service, will hopefully be resolved.

Originally Posted by Legal Alien

Also have the intermittent 1-2 sec belt squeal on start up - car is at the dealer today for 13K service, will hopefully be resolved.

Let me know what they say about the squeal. Thanks

My d has been quiet so far, but I was having annoying belt squeal on my M Roadster. Ordered the parts, and this past weekend decided to install new belts and idler pulleys. Problem cured - the engine is purring now! Even though the tensioners keep the belts tight, when they wear, the rubber seems to get polished (possibly by contamination?) and become noisy. BTW all the bearings in the idlers were somewhat loose and noisy too. The car has 44k miles and after changing everything it felt like it had a new engine!

Only happened once with me, backing out of driveway. 9k miles.

I heard the same noise in similar situations(backing up after cold start). It happened 3-4 times in 9K miles. I had it checked last month during 1st oil change and dealer said everything looks good. I could live with it for few times a year but I do agree that it is an embarrassing noise coming from a 50K car.

I've had the belt squeal occur a few times over the last several months, but just within the last two or three weeks, it occurs several times per week. I need to take the car to the dealer and have it looked at.

I have had the car for over a year and have 21K miles on it.

Originally Posted by cssnms

My car has less than 6k mi on it and I have noticed on several occasions that when I cold start my car, I hear a loud squealing/screeching noise that sounds a lot like a fan belt slipping. I first heard the noise while creeping along in slow moving traffic, but I was in denial at that point that the hideous noise I was hearing was actually coming from my car. Now after hearing it several times at start up to include this past Sunday, I can say with confidence this despicable noise is in fact emanating from my car.

I plan to take it in to the dealer, but I was curious if any of my fellow "d" owners has encountered a similar issue.

Is that screeching noise from your tires or any other part of the vehicle? If its fan belt issue, then certainly it must be loosening of the belt or due to dirt or less grease. I don't think so it will cost much if its taken to a dealer.

Originally Posted by klee

Is that screeching noise from your tires or any other part of the vehicle? If its fan belt issue, then certainly it must be loosening of the belt or due to dirt or less grease. I don't think so it will cost much if its taken to a dealer.

If loosening then why would it cost anything? I'd thought premature loosening of things would be covered by the warranty.

Originally Posted by Flyingman

Very annoying and usually resolved by a simple tightening of a loose belt.

Does BMW still use adjustable V belts? I thought almost every manufacturer had switched to serpentine belts with non-adjustable belt tensioners, e.g., no such thing any more as "tightening a loose belt."

Dealer could not reproduce, of course!;-) Recommended overnight stay to try replicate, but it happens very intermittently that I dont think it will be worth it. More of an embarrassment really on a ~$50K newish vehicle. Will see if it gets any worse over time.

Originally Posted by Penguin

Does BMW still use adjustable V belts? I thought almost every manufacturer had switched to serpentine belts with non-adjustable belt tensioners, e.g., no such thing any more as "tightening a loose belt."

Hmmm, don't know for sure, but it would seem logical that you can still loosen or tighten the serpintine belt to put it on and off and adjust tension. The idler usually is spring loaded to adjust itself to a point, but if making noise it is either loose of you have some other mechanical problem like a bad a/c compressor or bearing on a pump, etc...

You could also stop at any auto shop and buy a can of fan belt dresser spray. Just spray it on while running and it will eliminate some of the slipperyness.

I'd expect the dealer mechanic would have a specific procedure and specifications for tightness to verify as well.

I never have looked at the belt on this car. But just figured it is like most fords I have dealt with. On those you have one belt and an auto adjuster that has a pulley for lack of a better description. I actually never have had one of those go bad. Just every 100-150k miles I have to replace the belt. My mid 90s galant uses v belts and my old 2000 accord did as well, I was surprised to see that.

This has happened to me twice over the past few weeks. It is the first time I accelerate above 5-10 mph when the car has not been running and the a/c is on. I'm doing an oil change this weekend (third time @19,500 miles, doing every other myself during the 'free' period) and will take a good look. If it happns more frequently I will take it in.

My 2011 with 5500 miles has made the noise 5 or 6 times in the last 6-8 weeks. I've been able to narrow it down to only happening when it's at least 83 degrees (ambient air temp) and the car has been driven somewhere / sit for at least 30 mins before re-starting. I'll probably wait until it's consistently warm outside before taking it to the dealer.

there are squeals, then there are screeches. Squeals can be loose belts. Screaches presage failing pulleys. Failing pulleys are the bane of engines with serpentine belts, and quite the profit generator for the shops! If there is no automatic tensioner, then it is quite important to know the proper tension, and to have a gauge to then properly set the tension, otherwise the bearings fail prematurely.

Squeal still going STRONG. I have linked it to my AC. As soon as I shut the AC off it stops. It typically only happens at start-up, but there were those few times much to my chagrin while I was sitting in traffic and it started.

Yes, my service advisor said he had heard several complaints about this from customers. I am due for my one year service in July and he advised waiting until then.

Originally Posted by cssnms

Squeal still going STRONG. I have linked it to my AC. As soon as I shut the AC off it stops. It typically only happens at start-up, but there were those few times much to my chagrin while I was sitting in traffic and it started.

That makes sense. The serpentine belt has an automatic tensioner but it doesn't drive the A/C compressor. The A/C has its own belt and as far as I can tell has to be manually tensioned.