Yesterday when I started my car after work I heard an unusual ticking at idle, the belt tensioner hydraulic cylinder must be bad because the spring and idler pully are bouncing and causing the noise. I searched the forum and looked in my Bentley manual for directions on how to replace the tensioner but could not find guidance in either place. Does the engine have to be raised or lowered to do this job or can you do it entirely through the wheel well? I'm also curious about where to find torque values for the mounting bolts. If you know of a DIY anywhere I would appreciate knowing where to find one.

Thanks,

 

I did it without lifting the motor. I removed the wheel well liner, although the actual removal/re-installation was down and out, not off to the side. A bit like a chinese puzzle, but it can be done. I'm sure its easy for those who do it regularly, but for a first-timer it took some time.

 

Thanks JAB, it seems as though I will be attempting a Chinese puzzle on Saturday. I am encouraged to know that it can be done without messing with the motor mounts. Any other inputs from others who have done this job would be greatly appreciated.

 

I've done it a few times recently myself. I jacked the passenger side up and supported with a jack stand. Then the wheel liner came out. I found that laying on my back gave me the best view of the bolts. Make sure you release the tension from your belt and stick a small Allen wrench in the second hole of the tensioner strip. Once you have the bolts removed you will figure out how to bring it down and out. A Chinese puzzle is a great description but it's really not that difficult.

You're probably going to need to replace your tensioner damper bushings. Check those first. FYI rockauto.com has the whole assembly for about $90.00. They are about $180 from the dealer.

Good luck,

Chad

 

It can be removed by going through the wheel well. But it is easier to remove it by jacking up that side of the engine.

ratchet wrenches help too.

 

Thanks everyone... Does anyone have any torque specs? My new tensioner is on the way.

 

Thanks everyone... Does anyone have any torque specs? My new tensioner is on the way.

 

Just tight is good enough.

 

33 ft-lbs is the proper torque for the tensioner to the crankcase. I doubt you'll be able to get a torque wrench in there though. I did them like Way said, just tight enough with an open end wrench.

 

I learned a valueable lesson about my MINI. I hope that by relating my experience with my belt tensioner that others won't have to learn the hard way.

My belt started vibrating up and down and going tap..tap..tap at idle, additionally the tensioner pully was jumping up and down at the same frequency as the tap. I read a few threads here and came to the conclusion that my tensioner or hydraulic dampener must be the problem. I ordered a tensioner and began planning how to replace it.

To make a long story short, neither the tensioner nor the dampener were the problem. My belt was the problem There was one place on my belt where the ribbing had begun to separate. It was almost impossible to see with the belt on the car. Because I had replaced the belt only about 10000 miles ago I never considered the possibility that it was bad. The moral to this story is, a bad belt can cause the same symtoms as a bad tensioner, always try the belt first! My bad.

 

I have a high pitched whine coming from the belt tensioner general vicinity of my '03 MCS that sounds like a jet engine. The pitch increases with RPMs. I've heard a similar sound on an American V8 when the alternator bearings went. After listening to it with an engine stethoscope (rubber hose,) it didn't seem to be the alternator or supercharger. I thought maybe the timing chain so I took it to the dealer for a diagnostic figuring if anyone ever heard this before they would know instantly what it was. It's kind of like the whir you hear in the Mad Max movies when he engages the blower, so it does sound cool, but hey - that's only a movie.

The dealer told me it was the hydraulic belt tensioner and complained that I had an aftermarket belt on there (has been for 6 months) and said it might get better after replacing that, and if not then the tensioner itself. They quoted me $181 for the tensioner, $59 for the belt, and $450 labor. I said "no thank you."

So I found the cheaper tensioner from Rockauto (they're awesome!) Now I'm looking around to see how hard it is to take off and I appreciate your advice about tackling the chinese puzzle. You're right that the Bentley book is no help in that regard. My question should be an easy one to answer. It's regarding "releasing" the tension on the belt. I don't have the special BMW tool to release it and can't even find a way to compress the tensioner even a little. When I replaced the belt 6 months ago before, I had the same problem, but the old belt had broken completely so all I had to do was work the new belt around the damper while I turned the crankshaft with a wrench to get it on.

Thanks!