high pitched noise (like mosqito sound) from engine

rgunho

I have a Nissan X-terra that has a 3.5 litre engine. I believe it's the same engine they put in the 350Z. At about 20k miles it started to whine as the engine RPM increased. You could actually hear it go up and down with the RPMs. One of my friends said it sounded like it was coming from the front of the engine. Turns out the timing chain guides were defective and had to be replaced. There was a TSB put out by NIssan, but car owners weren't informed. I was told it didn't affect enough owners. They reapired it under warranty.