[mgorman87]

Just did this on my car. Very easy.

The belt and pulleys appeared to be in decent shape, apart from being dirty.

Belt appeared newish. Not sure if previous owner already replaced it.


everything came out pretty easily. if you don't use a breaker bar to relieve the tension, you will struggle.

putting the pullies back on is straight forward as well.

the idler pully is 30ft lb. When I torqued it, it felt very not tight and i went a little more cause I thought, "this can't be right". but it probably was. Just dont over tighten it.


Putting tensioner pully is also easy. I put a mark on the bolt with a sharpie so i knew when i hit 90 degree. this bolt is 18ft lb for torque spec. using a regular ratchet to get that extra 90 degree turn is pretty tough. had to use a lot of strength to tighten it all the way


printed out picture of the belt path. had it sitting on hood

the belt should be put on tensioner pully last. i didn't at first and i wasn't able to get the belt over alternator.

pulled it off tensioner pully, got it on all the other wheels and then it just slid right on the tensioner pully after that.

once you make sure all belts are seated properly, release the tension on the pully and i used my finger to pull out the locking pin.

checked it over once more and started up the car and nothing blew up.


i could easily do this again in 20 minutes or less.

[bimmerzeit]

Just did this finally on my 2007 328i with 269,400 miles! I recorded a DIY in 4K to help those searching the topic in the future. Any questions just drop me a comment and I'll do my best to reply asap.

[subframe]

FCP Euro has a kit for under $90.36 (with free shipping) (SKU: KIT-11287628650KT). The kit includes the belt, tensioner, and idler pulley. FCP Euro states that the parts in this kit are all OE quality. The belt is made by Contitech, the tensioner and idler are made by INA. The same parts on getbmwparts.com total out to $235 including shipping. Does anyone have experience with the FCP Euro kit?

[simsima90]

Hey guys,

Quick question, one thing lead to another and I ended up reusing the aluminum bolt for the belt tensioner as I had some issues taking out the pin from the new tensioner while setting the tension on the belt. Now I am wondering if I should replace it again with a new bolt.

So is it possible to take out the existing bolt from the tensioner that is already installed and the pin removed then replace with new bolt? Or do I have to buy a new tensioner since the pin was removed?

Thanks great forum btw!

[Steadyhand]

I've put that pin back in place before. Of course, it was possible (even relatively easy) because the tensioner was mounted and I was able to put the 60 torx in using a long breaker bar - the pin slipped right in.

[andy_06xi]

Just did this job. A quick heads up -- I was not able to install the new belt with the pin still in place. The pin locks the tensioner to a particular state of unloading and it was not enough for me to install the new belt.

Unloading the tensioner enough to remove the pin and then further unloading allowed me to install the new belt.

Other than this hiccup, it was pretty straight forward (although I do have the old idler pulley dust cover now sitting somewhere on my engine pan).

[The Nightman]

Originally Posted by freedomfries

Thanks for the DIY. I just replaced the accessory belt, tensioner and idler pulley on my 2009 E90 328i with 70k miles. Turns out the previous owner had already replaced the belt and tensioner as the tensioner bolt was not blue and the tensioner and belt had 2015 dates. I went ahead anyway since the idler pulley was original. I bought the Contitech ADK0022P kit which included:

1. Contitech belt (made in Germany)
2. INA tensioner, bolt, cap (made in Germany)
3. INA idler pulley, bolt, dust cap (made in France)

These parts are the same as OE as far as I can tell. Shop around for the cheapest price; I ended up buying from Rock Auto.

Update: the bearing on the tensioner started crunching/rattling after 14k miles:

I was only able to diagnose the noise with a mechanic's stethoscope where I could hear the bearings crunching in sync with the rattling sound. Upon closer inspection, the INA tensioner I installed had no country of origin marks while my old INA tensioner said Germany on it. According to FCP, the new tensioner is made in Slovakia: https://www.fcpeuro.com/products/bmw...em-11287530314

It seems that INA moved production to Slovakia as the "BMW" tensioner is also made there: https://www.fcpeuro.com/products/bmw...ly-11288624196

I refitted the old German INA tensioner with a new aluminum bolt and the rattling disappeared. For whatever it's worth, the German tensioner was marked "04.02.15 J.5" while the Slovakian tensioner was marked "07.12.2016 K.5"

[mainbearing]

In the past week getting a chirping noise from the engine bay on cold starts. The noise would go away after a short while as the engine warmed up.

Good thing I took a quick look this weekend, thinking it might be the alternator because the INA belt tensioner was changed 5 years ago and I was not expecting the "new" assembly to fail like the factory one. Popped the engine hood, and the serpentine belt was hanging 1/3 out the pulley!

I took the belt off and noticed the entire tensioner assembly was rocking loose. Turned out to be a failing tensioner bolt. The bolt head almost sheared off. This engine was close to ingesting the serpentine belt through the front main oil seal.

Good thing I had an extra bolt because I did not know INA would include one with their tensioner. Used the new bolt to reinstall the old assembly, and the belt was back where it was, about 1 mm inside the edge and running quietly. The front edge of the belt was very slightly scraped up, but it will do.

This makes me wonder how much of the tensioner failure problem was solely the mounting bolt failing and not the tensioner assembly itself. Should have tried to reuse the original assembly. LOL

Looks like the grade AL9 aluminum bolt just was not strong enough.

Failing bolt on top, against a new bolt below:

[mainbearing]

Had a belt walked 1/3 off the pulley problem this weekend. Turned out to be a failing mounting bolt. The AL9 aluminum bolt was not strong enough. Makes me wonder how much of the problem was the bolt failing and not the assembly's fault.

My post here:
https://www.e90post.com/forums/showthread.php?t=1976331

And pics:

Failing bolt on top, against a new bolt below: