[badbread]

FWIW I made a DIY here on changing it out.

After I installed the new tensioner in my car, the jiggle was gone.

See here for the DIY and the video of before and after: http://*************/tensionerdiy/

[rcsup1]

Your dampener has a slight wobble which will get worst. This is probably what cause your tensioner to go bad in the first place. Mine is much worse, I plan to replace it soon to avoid another tensioner failure.

[Busa1]

I was looking at engine the other day and noticed the belt tensioner shaking a little and thought that wasn't normal. Then by chance I stumbled upon this thread. I'm going to order a belt tensioner, belt and a new set of plugs. On the people who replaced the tensioner and belt, how many miles were on your car? I'm just under 30K.

[Orion4]

Changed my Belt, Idler Belt Pulley and Belt Tensioner around 100k. Easy, straight forward 30-45 min DIY

[Eschmacher]

Glad I found this thread, made me check my tensioner, was also wiggling. Grabbed a new one and a new idler and belt for shits and giggles. I just hit 50k.

[Pray for Mojo]

Originally Posted by badbread

FWIW I made a DIY here on changing it out.

After I installed the new tensioner in my car, the jiggle was gone.

See here for the DIY and the video of before and after: http://*************/tensionerdiy/

Thanks for this, your write ups are the best. Did you change the idler pulley as well? It sounds like it should be changed at the same time as the belt.

My lost to belly pan item count is up to 5.

[Pray for Mojo]

Did mine tonight, oddly enough my 235i tensioner needed a T55 and E14 vs the T50 and E10/12 the F30 folks required. This was probably the easiest thing I've replaced on any BMW. Took 25 mins total and it's dead steady now. A 5/32" R lock pin for a trailer hitch worked perfectly to hold the tension during belt removal. I ordered a new idler pulley but mine seemed fine on inspection. I'll probably replace it next time I do anything else on the car.

[Insane435]

Originally Posted by Pray for Mojo

Did mine tonight, oddly enough my 235i tensioner needed a T55 and E14 vs the T50 and E10/12 the F30 folks required. This was probably the easiest thing I've replaced on any BMW. Took 25 mins total and it's dead steady now. A 5/32" R lock pin for a trailer hitch worked perfectly to hold the tension during belt removal. I ordered a new idler pulley but mine seemed fine on inspection. I'll probably replace it next time I do anything else on the car.

Good info on lock pin. Going to need that when i decide to do my idler soon.

[lens]

Just an update.

I had my car eat through 3 belts and 2 tensioners before we found the actual problem.


Front crank seal.

If the front of your block has excess oil, or oil on the inside of the belt, runs lean, or the tensioner continues to jiggle even after replacement, I would highly suggest you check your front crank seal. Mine was worn to the point where it would create a vaccum leak causing my car to run lean as shit and stall. It would also spit oil everywhere which caused the belt is slip.

After replacing my crank seal, the tensioner is rock solid, and the car runs great now. I am still going to check it now and then to make sure, but I'm pretty sure that was what caused the problem.

[upsidedownfunnel]

I've seen a few nearly new N55 motors and they all do this jiggle. I don't think it's a sign of impending failure and I think anyone that fixes it is just going to see it happen again after a year or so.

[lens]

Originally Posted by upsidedownfunnel

I've seen a few nearly new N55 motors and they all do this jiggle. I don't think it's a sign of impending failure and I think anyone that fixes it is just going to see it happen again after a year or so.

There's a certain amount, very minimal, but when it starts moving, you'll notice it's not normal at all, and that's when you should be worried.

[Tommy335]

Definitely change it! I just got two recalls done at bmw and one being the OFHG and on my way back home just as I was pulling in to my driveway the battery charging light came on and there was a pool of oil on the floor not sure what happened but I'll be contacting them tomorrow.

[nyc_dude]

Definitely change the Idler Pulley too, since the bearings inside wear and fail.

Need special sockets/tools for this quick job...T55/T60, E12/14, etc. Plus a drill bit or thin philips screwdriver to uses as a pin for the old belt tensioner.

Keep the old parts.

Cheers

[thejeremyman9]

Bumping a little bit of an older thread here hoping to get input -

TLDR - is the amount of wobble in the video below normal?

I was inspecting the engine bay with the car running after installing my MST inlet yesterday and noticed a little bit of wobble on the belt tensioner. If you look closely, the crank pulley also seems to have a slight wobble in it... Not a crazy amount on the crank pulley, and kindof hard to see in the video, but its definitely not rotating perfetly with no side to side or front to back movement.

After watching the Kies video, it looks like at a minimum the tensioner might be moving too much. What do you guys think?

[Tpriest7893]

Originally Posted by thejeremyman9

Bumping a little bit of an older thread here hoping to get input -

TLDR - is the amount of wobble in the video below normal?

I was inspecting the engine bay with the car running after installing my MST inlet yesterday and noticed a little bit of wobble on the belt tensioner. If you look closely, the crank pulley also seems to have a slight wobble in it... Not a crazy amount on the crank pulley, and kindof hard to see in the video, but its definitely not rotating perfetly with no side to side or front to back movement.

After watching the Kies video, it looks like at a minimum the tensioner might be moving too much. What do you guys think?

Is this going to be our next DIY lol?? I need to check mine out

[thejeremyman9]

Originally Posted by Tpriest7893

Is this going to be our next DIY lol?? I need to check mine out

I hope not lol... I know the tensioner is a easy DIY but i am worried about the crank pulley itself.

I am mostly wondering if other people can go out and look at their car at idle and see how the wobble of the crank pulley (and tensioner) looks compared to my video. ozymandias435 said his looked just like my video, but looking for a greater sample size lol.

[Korvo]

Originally Posted by thejeremyman9

I hope not lol... I know the tensioner is a easy DIY but i am worried about the crank pulley itself.

I am mostly wondering if other people can go out and look at their car at idle and see how the wobble of the crank pulley (and tensioner) looks compared to my video. ozymandias435 said his looked just like my video, but looking for a greater sample size lol.

My tensioner looks the same, if not a little worse. The shop foreman at my local dealership told me it was normal.

The DIY looks easy, so I just bought the parts. Something to do!

[obeeone]

Originally Posted by thejeremyman9

I hope not lol... I know the tensioner is a easy DIY but i am worried about the crank pulley itself.

I am mostly wondering if other people can go out and look at their car at idle and see how the wobble of the crank pulley (and tensioner) looks compared to my video. ozymandias435 said his looked just like my video, but looking for a greater sample size lol.

Just shot a video of mine, it's kind of dark so hopefully it'll work. Also just hit 40k miles today.

[thejeremyman9]

Originally Posted by pdegene

My tensioner looks the same, if not a little worse. The shop foreman at my local dealership told me it was normal.

The DIY looks easy, so I just bought the parts. Something to do!

Thanks for checking.

Originally Posted by obeeone

Just shot a video of mine, it's kind of dark so hopefully it'll work. Also just hit 40k miles today.

Yours looks rock solid... both the crank pulley and the tensioner. I am at 46k miles which makes me think mine might be at least starting to have an issue.

[aps]

Originally Posted by thejeremyman9

Bumping a little bit of an older thread here hoping to get input -

TLDR - is the amount of wobble in the video below normal?

I don't have a recent video, but I did look at mine the other day and it looks like similar to yours - maybe a little less play in mine. I'm at 77k. I don't believe it's normal because when I changed my tensioner and belt out at ~64k, the crank pulley didn't seem to have any play at all and looked more like the video from obeeone.

Not sure if this is normal wear and tear over time or if this needs to be resolved asap, but it is in the back of my mind now.

[Eschmacher]

Mine isn't as apparent as your video, but I've been suspecting my crank pulley is wobbling as well. My tensioner has been replaced multiple times and it always jiggles.

I mostly suspect the crank hub because I have a small amount of oil appearing around it. Not sure if it's coming from the crank seal or a plug that's right next to it. i was planning on removing the hub and cleaning the area under it as well as inspecting the crank seal. Something tells me this is just paranoia though.

[F32Fleet]

Originally Posted by thejeremyman9

Bumping a little bit of an older thread here hoping to get input -

TLDR - is the amount of wobble in the video below normal?

I was inspecting the engine bay with the car running after installing my MST inlet yesterday and noticed a little bit of wobble on the belt tensioner. If you look closely, the crank pulley also seems to have a slight wobble in it... Not a crazy amount on the crank pulley, and kindof hard to see in the video, but its definitely not rotating perfetly with no side to side or front to back movement.

After watching the Kies video, it looks like at a minimum the tensioner might be moving too much. What do you guys think?

That's normal. They all have a slight wobble.

IIRC the belt starts to squeak when the tensioner needs replacement, or the belt doesn't track straight, or you hear the bearings making noise.