Nissan Repair: Noise coming from 2002 nissan xterra, nissan xterra, wd40

Question
I have a 2002 Nissan Xterra that has a squeaking noise coming from under the hood. It does not make the noise until the car warms up. At first it was only making the noise when the car was in gear. Now it is making the noise all of the time (except when you first start it). My husband thinks it is coming from underneath the vehicle near the transmission. I just got the transmission fluid flushed and it still makes the noise. Any ideas?

Answer
Hi Carleen -

First of all, check the belts. Does it make noise when the A/C is turned on? Fast way to check is spray some WD40 on each belt one by one while the engine is running (do not overspray). If the sound goes away, then replace the belts.

Could be also the exhaust rubbing against something, or mounts.

Please do the belt check and get back to me -

Thanks
aloha
calvin