Wondering how long y'all are going before the idler pulley starts acting up and needs replacement. I'm going to have to replace my serpentine belt soon. Checked the idler pulley, spins smoothly and there's no sound from the bearings. I replaced it a little over 60,000 miles ago. There is a very tiny bit of play (almost imperceptible) back and forth but I think that's normal? Just wondering if I should replace it while I'm doing the belt since I'll have the wheel liner pulled back anyways.

 

Since you'll be in there anyway, I'd say that its cheap insurance. I've put 70k on Tigger and have replaced mine twice, each time I've replaced the belt (note that once I had dropped metal shavings onto a pulley and it got buried in the belt-so I changed it-My bad)
HTH,

 

Bought a new car (Porsche) in Jan 2002. Was aware of it having a convoluted accessory drive system with several idler rollers and a tensioner roller. I just felt these were not going to last. So I bought a set of factory idler rollers and a tensioner and put it in the front trunk. It still still there 16 years and 317K miles later.

In the meantime in June 2009 bought a used 2003 Porsche 996 Turbo with < 10K miles and in pristine condition. And with a 2 year 100K mile CPO warranty. At around 30K on a road trip heard a noise that proved to be a bad idler roller bearing. At the dealer the bad one was replaced under warranty but I paid to have the 2nd one replaced along with the tensioner. Skip some years. On cold start heard a chirp. Once again a bad idler roller bearing. And once again I had both idler rollers replaced along with the tensioner.

My point is you can't know when the idler or tensioner roller bearing or any accessory drive -- most often the water pump -- can go bad. You just have to be aware of any appearance of an odd sound and have it investigated. And with a water pump it may not make any noise. While one car's water pump did make noise at cold start at 170K miles with another car the only sign I got of what proved to be a bad water pump was on a hot day with my Turbo's engine idling I smelled anti-freeze. A sure sign of a leak. Sure enough at the dealer it was clear the water pump seals were leaking.

One sign of a possible accessory drive problem -- worn bearings -- is an edge of the serpentine belt will get sharp. With the engine with the noisy water pump the inner edge of the belt was sharp. The other edge was dull. I checked the old belt -- replaced as called for after 60K miles -- and both edges were dull. I checked accessory drive play and found the water pump had some. The bearing play causes the belt to not track true and the inner edge contacted the side of the water pump pulley and the sharp edge was the result.

It has been too long ago to trust my memory of whether new/good idler roller and tensioner bearings feel like.

If you have any doubts about the idler roller bearings and tensioner roller bearing my advice would be to replace them while you are there.

When you do so with new and old idler and tensioner rollers available you can check play and determine if the old idler and tensioner roller bearings have normal play or excessive play compared to the new ones. And if the new bearings have any play what is *normal*.

 

Alright, guess I will do it then. Looks like a new pulley on rockauto is about 20 bucks. Cheap enough.

 

I had taken mine off just to check it, had no issues while running, bearing seems perfect and all. But when I took it off, the little spacer behind the pulley was all chewed up for some reason. I replaced mine from ECS tuning just to play it safe. Engine is out anyway so Im replacing everything besides pistons/rings, car has perfect compression at 165k miles still, just leaked a ton of oil.

 

I bought mine from FCP Euro and they provide a lifetime no-hassle warranty. I have no affiliation with them, but I think it's cheap insurance to go with them if you plan on keeping the car for a long time. It was $26 there for OE brand (INA) for my R53. They also sell a kit that has the idler pulley, tensioner, belt, and hardware for $158.