I was under the hood the other day and I noticed that when the motor is idling, the pulley on the tensioner bounces around on the belt a little. As soon as I get the motor reved up a little bit over ideal, it goes away.

Is that normal for the pulley to bounce around on the belt like that when the motor is idling? It's say it's bouncing up and down around 1/8" total. Does that mean that the tensioner damper is worn out and needs replaced?

 

Sounds like it is worn....like the gas strut on it is weak/dead....and just the spring is holding it on...i surmise the strut is to help reduce the bounce of the spring. I know my local mini guy reccomends replacing the tensioner every few years to avoid this, and the possible tow/dammage if the belt jumps...about $130-150 to ensure relilibility....
Also look at the crank pully...make sure it is not wobbling...they fail, and you might be seing the tensior trying to do its job....

 

^ +1

 

Would a tensioner going bad cause any sort of sound, like a squeaking belt? Sometimes I worry about mine, although I really only hear the squeak when I start the car up for a few minutes until it gets warm. Not the crazy-loud, "something is definitely wrong" squeak, just a subtle sound coming from around the tensioner.

 

How hard is it to get in and change the tensioner dampener?

 

The only time I've messed with it was when installing the pulley, which necessitates lifting the engine up a couple inches out of the engine bay. That takes a bit of work, but not too much. Me and a few friends managed the whole job in about two hours. So I would imagine, at worst, changing the tensioner parts would be the same.

Oh, and if you're going in there, deffo pop in a smaller S/C pulley. It'll add about $150 to the total expense and make a world of difference.

Edit: Unless the JCW edition already has one? I dunno...

 

I replaced my tensioner a year ago and the strut is already bad. Is there any solution other than buying the whole tensioner assembly every year!?

 

You can also do it from the wheel liner, but you might need to jack up/support the engine to get comfortable access to the top half and the hole to compress the spring...

 

I thought I started a thread on this but I can't find it anywhere.
Here's a video I took of my tensioner bouncing. It goes CRAZY when the AC is on at idle.

http://www.youtube.com/watch?v=O4lAA...eature=mh_lolz

I actually wasn't sure what the noise was at first and when I took this video I discovered what seems to be causing the problem.

 

Do share - was it too long a belt? A seizing alernator/compressor?

 

The belt I have ended up being very close to too short. I had the tensioner compressed to the max and had to struggle to get the belt around the idler pulley. The sound from mine wasn't too bad after that but quickly got worse. I'm guessing the belt has stretched enough for the tensioner to start bouncing again.
I don't think the alternator or AC is seizing or else I would be seeing other issues. I do have a 2% crank pulley and 16% reduction pulley. Now I just have to decide the proper tensioner to buy.

 

Noticed torn bushing on my belt tensioner damper/strut. Car otherwise drives fine. Bought the new Alta adjustable tensioner to replace damper/strut with, but removed as I could not get the correct adjustment to stop belt squeal noticed with brisk throttle in neutral. Squeal was not present prior to trying the adjustable tensioner. I re-installed my old tensioner damper.

I see that the tensioner arm (metal plate with holes) within the spring of -my belt tensioner seems to be vibrating/moving up and down like a pogo stick at idle. The damper/strut on the belt tensioner also seems to telescoping in and out a lot at idle.

When revved in neutral, the tensioner arm slides down the center of the spring and no holes are visible for an instant and then returns to one hole showing, although moving like a pogo stick still.

With the Alta adjustable tensioner installed, there was essentially no pogo motion of the tensioner arm during idle or brisk throttle in neutral.

What is the normal motion, if any, at the belt tensioner arm at idle? with revving in neutral?

Anyone know how much resistance to close/extend the tensioner damper is supposed to have? It seemed pretty light to manually move it after I had it out.

I'm debating whether to get Powerflex damper bushings or just replace the entire belt tensioner.

Thanks!


05 MCSc 87K miles, 15% pulley, new-ish NAPA 60535 belt, ATI Damper/harmonic balancer...

Update: MINI mechanic had a look and says my tensioner is moving normally. I guess I'll just monitor the small crack in one of the tensioner damper bushings for now. Car drives fine...

 

tensioner arm should not move much at all. The strut wears out very quickly and then you get movement and belt slip.

I just installed one of the Alta fixed tensioners today for a friend/customer.
It only requires a little tension. When you put the car together, the spring will provide essentially all of the tension needed by the belt. Adjust the Alta tensioner to give an extra 1-2mm, just to prevent the belt from going slack.

The spring is motionless after installing the Alta tensioner. With the stock strut, the spring will bounce around quite a bit.

I had installed the powerflex bushings on my car because the stock bushings had worn out. It made no difference to the belt slip and spring bounce. I like the Alta tensioner design so much, I ordered one for my car.

 

So if your car is destroying the dampers quickly would that not make you think you could have other problems?
And when you took the belt off to replace the tensioner, did you check to see all the pulleys spun freely?
I would go ahead and do that before i went and put the alta part on my car.
usually its a sign of dying parts if its taking out the tensioner...
Kurt, you have customers now?
I missed you at mini thunder this year, total bummer.

 

Hey there.

Yes, I have 'customers' once in a while - just helping out the local MINI club members with repairs and mods. Not sure if 'customer' is the right word....

All the pulleys on my car and on the 'customer's' car are spinning freely.
His car had 90,000 miles on the original dampener, so was due for a change.

My car has seen a lot of track time in the past year and I drive it pretty hard on the street as well - not a lot of highway miles, so it sees a lot of varying RPMs every day.
I think that's what did it in. That and the 244HP.

Hoping to make MINI Thunder 2013...!

 

I changed mine, its been fine ever since. its been about a year.
I did see you got a head, now you just need a bigger header.
should be set.

 

I have a Milltek header. Not big enough? :-)

 

I am resurrecting this thread to ask if the folks around here would recommend swapping out the stock tensioner with the fixed one from ALTA as a way to stop my belt from squeaking when cold and (especially) wet.

I don't want to spend the money and do the work for nothing, though. Is it worth it? Will it solve the problem?

Also, how worried should I really be about a belt that squeaks when it's wet? Is it just something Minis do?

Thanks.