loose belt tensioner noise?

[DV-F15]

Hi guys,

Recently I've been having some extra noise (kind of like a squeal and whir) in cabin and while I was under the impression it may have been something due to the weather, I happened to take a look under the hood anyways. I managed to find the belt tensioner looks a little loose at idle, and given the noise gets louder as rpm's increase I'm inclined to think that it may be the culprit.

Can anyone confirm the tensioner needs replacement, is it urgent or can I wait a week or two to go to a mechanic? If I have the tools I'd do the job myself.

View post on imgur.com

[XxBBVTMxX]

Originally Posted by DV-F15

Hi guys,

Recently I've been having some extra noise (kind of like a squeal and whir) in cabin and while I was under the impression it may have been something due to the weather, I happened to take a look under the hood anyways. I managed to find the belt tensioner looks a little loose at idle, and given the noise gets louder as rpm's increase I'm inclined to think that it may be the culprit.

Can anyone confirm the tensioner needs replacement, is it urgent or can I wait a week or two to go to a mechanic? If I have the tools I'd do the job myself.

View post on imgur.com

Definitely something is not right.

If I were you I'd check two things first..

1) make sure the asa bolt (07129906293) that holds it in place is torqued properly.

2) see if you can move it yourself (arm has play). If so, then yeah you need a new tensioner.

The job is pretty easy to do. You should look up YT videos on how to DIY. I'm sure there's gotta be one out there. Also, not sure what year your F15 is but as of 2015 it looks like there's a new mechanical tensioner that superseded 2014 and below (11288604266).

I'm just going off your video. I have a 35d, different type of tensioner on mine.

[bmwx5_50i]

Something else to check, does the noise go away when you turn off the ventilation? The blower motor has a tendency to "whine" in sync with RPMs. Nothing you can do about that unfortunately I think. I had mine replaced and the noise persisted.

[DV-F15]

Originally Posted by bmwx5_50i

Something else to check, does the noise go away when you turn off the ventilation? The blower motor has a tendency to "whine" in sync with RPMs. Nothing you can do about that unfortunately I think. I had mine replaced and the noise persisted.

nope! first thing I had thought, but it's definitely from the engine bay. motor is high mileage so it definitely makes sense. gonna go to the mechanic tomorrow.

[phipark]

Quite possible you need to replace the tensioner after 100k. You'll want to get that done asap because of the belt falls off, you'll be in much bigger trouble.

[Freude_am_fahren]

There can be other causes for this, but the easiest approach is to replace the tensioner and belt and then see if the issue is still there or not and go from there. It is advisable to change tensioner and belt together.

[tlow98]

I replaced the belt and the tensioner at the same time. There was noticeable wear on the tensioner bearing. This was around 85k miles.

[DV-F15]

Originally Posted by phipark

Quite possible you need to replace the tensioner after 100k. You'll want to get that done asap because of the belt falls off, you'll be in much bigger trouble.

Wish I hopped on this a bit more urgently! While driving a short distance today I drove over some debris and shortly after my 'battery is not charging' warning came on. Sure enough, my tensioner is way out of alignment and my pulley snapped right off.
Quickly drove the car home and she's sitting now. Replacement ordered as well.

My issue, however, is whether or not I’m able to drive the car 20 minutes to my mechanic (I don’t have time to fix the car this week and I need it on a short time frame). Probably going to tow the car, but do you have any idea if the water pump runs off the belt as well?

[tlow98]

You could prolly make it in the daytime if you have every thing turned off. Have a battery charger?

[DV-F15]

that I don’t, car will be sitting for two-ish days I'd hope it starts up fine. Tow might be more convenient though thinking about it...

[Freude_am_fahren]

In my opinion 20 minutes is not going to work or the risk is in my opinion quite high that the battery won't make it. The battery is already weakend a bit from your drive today.
About the water pump, I don't know which X5 you have exactly.

which pulley snapped off? that of the tensioner?

[DV-F15]

no the other pulley in the assembly. 35i, i know the diesel engine runs the water pump as well.

[Freude_am_fahren]

To my knowledge the N55 engine has an electric water pump and the belt runs over tensioner, alternator, idle pulley, ac compressor, crank.
I hope the belt didn't damage more in your car and the ac compressor and the hoses around the belt are still intact.

[DV-F15]

Originally Posted by Freude_am_fahren

To my knowledge the N55 engine has an electric water pump and the belt runs over tensioner, alternator, idle pulley, ac compressor, crank.
I hope the belt didn't damage more in your car and the ac compressor and the hoses around the belt are still intact.

Thanks friend. Everything still looked fine at a quick glance. No liquids from hoses and ax compressor looked good. Minor setback but I'd rather failure close to home than on the road.

[1004ron]

The failure mode that leads to the tensioner oscillation is a worn or contaminated (oil) friction damper - not a worn spring as many suggest.

A previous vehicle of mine used a flat friction disc whereas these have a friction drum.

My old X5 tensioner was dry but worn out.