Today I noticed a very loud thumping noise from inside the truck while coming to a stop light.. In all honesty I thought I had dropped a valve it was knocking so hard. I pull over and look under the hood and noticed the noise seems to be coming from the turbo side. After a quick inspection the sound seemd to be coming from water pump area. I shut the truck off and checked for any loose pulleys and obvious visual problems and found nothing. I restarted the truck and of course the noise starts again. For some reason I decided to turn on the AC to see if its the compressor pulley and sure enough the noise goes away.. Any ideas?? Everything reads fine and AC works great.

 

It's the compressor clutch bearing. It only turns when the compressor is NOT engaged. If you get a belt for a NON AC diesel it will bypass the compressor until you can fix it.

 

Is this an easy fix???

 

Depends.... if caught in time before any damage is done to the coil or clutch pulley that's why I suggest replacing the belt with one from a non AC diesel and bypass the comp until fixed. The system does not need to be discharged all that needs to happen is the front clutch plate has to come off then the clutch pulley needs to be pulled and bearing replacement is easy just make sure the retainer is seated properly. Finding a puller may be the most difficult part if you don't have one.