[2004 Infiniti G35] Changed belts, now they squeak

I had the belts changed on my 2004 Infiniti G35 6-Speed Sedan according to the mechanics advice (they were cracked quite a bit). Now that they’re changed they make an annoying squeaking noise which is particularly awful when idling with my windows open. When I took it back, he said the pulleys need to be replaced and they are already at maximum tension. They did not squeak before the replacement. Is he right? Or did he just put in a belt that’s longer than it should be?

Usually a belt that is longer would cause much more serious issues, like the Power steering or the AC not working or the car over heating, all depending on what is driven by the belt. You probably have a weak tensioner, it was kind of fine with the older/weaker belt, but the new belt has changed things and the tensioner is acting up. I tend to agree with your mechanic. You can always get a 2nd opinion though before you put more money into it.

I’ve had this happen after I’ve replaced belts.

What happens is, when old the belt is removed from the tensioner/pulleys after so many years, the bearings in the tensioner/pulleys wear a certain way. Then when the new belt is installed and the tensioner/pulleys are rotated while installing the belt, it rotates them to a different position. Then when the tension is reapplied to the belt the bearings can start to squeak.

I call this, “The bearings are no longer in their happy place”.


I agree with the experts above, the mechanic has probably made the right call.

Doesnt that vehicle have ONE belt? If so…it better be the right size. Also…open the hood and have a looksie while its running…see what you see belt wise. There are TWO different noises this procedure can cause…one is BELT NOISE…the other is BEARING Squeak… Ive been doing this a LONG time…and trust me you can tell. But I can understand that this can be a bit of a hair puller.

Its either the belt or one of the pulley bearings… not much help huh?