My 07 diesel sometimes sounds like a school bus. You know the extra high pitch whining sound. It sounds like a school bus. This only happens when it is a vary hot day and the truck has warmed up and hand had a good run. I also experiance a bit turbo lag, about 4-6 seconds. If I turn off the truck for about 5-15 minutes the symtoms go away and then sometimes will come back vary soon or not at all. I spoke to the dealer about this and had the truck with me at the time of this problem. He did not have a diesel mech. available at the time to test drive my truck. He did mention that it sounds like an EGR valve sticking. He booked me in on Thursday and kept my ride till Friday afternoon. Nothing. The mech. found nothing, he test drove the truck for about 20 minutes and could not duplicate the same. No error codes showed up either. Here it's Sunday and it happened again. The dealer told me that if they can't find the problem they can't fix it. Any idea's to what is causing this.

Headviking

 

when do you hear the noise? on acceleration? decel? idle?

 

Headviking,

Sounds like the "Visconic" PCM controlled fan engaging to cool the radiator. The PCM controls the amount of lock up of the fan based on ambient temp, engine coolant & oil temp, engine load etc.

 

All diesel engines make that sound when the fan kicks in to cool the radiator. If you haven't owned or driven a diesel before, you might think your truck is going to fall apart but it won't. That is just what happens when your truck gets hot! It will be okay.

 

it sounds like a school bus because it is the same engine. the VT 365 is in almost all the new international school buses. there is a grade school down the street from me so i get to hear them alot.

 

I dropped in at my local dealer today while I was experiancing the turbo lag and the loud whining sound. The mechanic test drove my truck and said that my turbo was not kicking in as fast as it should. He is going to remove the turbo to take a look at the fins to make sure thay are not sticking in the open or closed possision. He will also take out the and checking the EGR valve to see if it is not coated with carbon. He did make mention of the load rad fan and will be checking into that as well. I will be dropping my ride in on Thursday morning for the day and maybe two. Will keep you posted on the results.

 

Well I picked up my ride on Friday. The dealer replaced my EGR valve (turbo lag) and my cooling fan clutch assembly (Whining sound). It drives like the day I picked it up new.
Headviking