'02 non s
My tensioner sounds like it has a bearing failing (makes a squeaking noise) and the crank pulley seems to be hopping/wobbling, with the belt squealing. Don't know if I should order just the pulley? Or if there is a problem with both. Any help would be appreciated so I can order the right parts and get the job done right.

 

The harmonic balancer is one of those items on the MINI that seem to be a "when it fails, not if it fails item." When the balancer fails, it separates into two pieces, causing all of the accessory items driven by the serpentine belt to stop spinning. We have a great DIY here with a step by step process to replace it as well as much more valuable information on it. We have a pulley and belts here for your R50 if needed. Over time, the serpentine belt can stretch. The tensioner setup is designed to allow a certain amount of flex to account for stretching as well as vibration. Over time, the tensioner can fail, possibly causing damage to the crankshaft pulley if the tensioner stop fails. We have a DIY here for this as well.

 

So is that the only way for it to fail? If it's not physically broken is it doing fine? If I replace the tensioner and belt is it something that I should replace with these parts, even if the money is a little tight? I have 85k miles on my car.

 

For the tensioner, I often use a can of WD-40 with the spray nozzle extender attached to try to isolate which pulley or piece of equipment is making the noise. With the engine running, I typically spray the bearing and listen carefully for changes in the squeaking noise. Often, the noise will go away when the lubricant finds its way to the bearing. Avoid getting this on any other component. Another way to check the pulleys is to remove the drive belt and actually turn them with your hand. Sometimes you can feel significant resistance or hear a grinding noise. Sometimes a squeaking noise may be caused by a belt that is deteriorating. As belts age they sometimes get worn out and smooth, and that may cause them to slip, which can result in a squeaking noise. The pulley hopping/wobbling is what concerns me and I would get it replaced. I'd stick to OEM supplier parts for this.

 

My instinct was right, the bearing on the tensioner was squeaking, changed it
Out and it's quiet, also fixed my power stutter with ac on problem.