I recently changed Belt, both the tension Pulleys (Tension an the 70mm), fan, Thermostat. Everything runs smooth. Except this annoying noise. The Noise comes (sometimes) when I am driving and at a stop. Seems like some pulley is about to come off - But when I put in Park the noise goes away. By the way I do have the drive shaft changed to have double U joints.

I checked all the Pulley's but did not see anything loose. When I look at parked the noise is not there.

Any help will be appreciated.

 

If it's the shaft, it won't do it while you are stopped unless you shift gears (i.e. shift in to P). You might hear a thunk when you switch gears.

The first thing I would do is take the tension off the belt but leave it in place. Then check the idlers to be sure the bolts haven't back out.

Then I'd put the belt back on and be sure it's squarely seated on every pulley. Then test drive.

If it's still doing it, have someone sit in the drivers seat while the truck is running and in D. Set the E Brake and make sure they keep their foot on the brake. Open the hood and see if you can tell where the noise is coming from. Because the noise is intermittent, you may need to load up a friend and have him drive you around til you hear the noise, then jump out and stick you head under the hood with a flashlight.

Just remember not to get any clothes or fingers stuck in the belt or fan.

 

Thanks. that was my next move. I will report back if I find anything. what puzzles me the noise is completely gone when I put the truck on Park. May be the change of idle.