salimshah

idler is ( 2 => are) the free roller on the belt used to change belt direction. This roller does not drive anything. Since it does not drive anything, it also does not get lubricated. Over time, the roller dries up and it starts overheating as the belt still spins it. One can spot the heated idler as it turns blue. Even if it has not changed its color, people pre-emptively change it, thinking that 180k will be too much to expect.

Salim

e-man

Each one costs around $70, so for $140, I take it you would say to change them both at 90k?

salimshah

It is a tough call.

If you see discoloration then it is a must replace. If not it is in the same class as water-pump.

I have not seen any published numbers on life of water-pump and the idlers. There is no specified reccomended milage for replacement of these items. People just replace them pre-emptively. The thought is, every thing is opened up and few more dollars can potentially save a lot more.

Sorry for being vague, but that is the truth.

Salim

e-man

That makes sense. The thing with the water pump, though, is that you can't tell just by looking at it if it's about to give out. I guess I'll just buy the idler sub assemblies and let my mechanic make the call once he gets in there. If the original ones look fine, I'll tell him not to bother replacing them. Then again, for $140, why not just replace them? I guess you could say that for a lot of parts, though. It seems to me that the life of the rollers would depend on whether the car has been driven hard for most of it's life, and I know my car has not been.