Nissan Repair: Strange noise??, expert diagnosis, noise engine

Question
Hello Calvin,
I drive a Nissan Sani v6 3.0Lit. '98 model. I tow a caravan often and hear a strange "tttrrrrrrrrr" noise under the dash down at the foot pedals area or in that vicinity when the vehicle is under load especially at plus/minus 3000rpm in 3rd gear. It almost sounds like a relay or something?? If i lift my foot off the accellerator or change to another gear the noise goes away. It is not a 'pinging' noise....engine recently tuned and "chipped" so furthermore no problems...pulls well. What i would like to know is what electronic component in abovementioned area could cause this noise and could this cause further serious trouble? Does not do this all the time...an intermittent problem.

I thank you very much, and await your expert diagnosis.

Darryl  

Answer
Hi Darryl -

Try checking the transmission motor mounts. When they get worn, it is a metal to car frame contact and you hear (and feel) everything in the trans.

It is difficult to diagnose something one cannot see or hear, so I apologize for that. I am not sure what kind of noise it is, but I think it is transmission related.

Hope this helps -
aloha
calvin