High pitch squeal, not brakes, Why?

[ssiic175]

Just had service at Gafney and about 400 miles later picked up a squeal. Sounded like a power steering or belt squeal. After paying close attention it was not happening when I made a turn. Only time I hear it is when the boost is rising, like starting out, accelerating etc. Any ideas as to what it is? Is this a Freightliner question or a Cummins question.

We have 72000 miles on a 2006 ISL 400 hp, Winnebago Vectra

[doc]

turbo spooling up?

[bigskymt]

Sure sounds like Turbo from your description, a Cummins issue.

[Elkhartjim]

I too left Gaffney last week where I had service and also attended Camp Freightliner. It was pounded in us to call 1 800 FTL-HELP with the last six digits of your vin at the sign of any problem. You might give it a try.

[Cat]

Turbo boost leak. Bad hose on aftercooler or loose aftercooler hose clamp. Thats my guess.

[WGOJERRY]

I had an intermittant squeal on my 2000 wgo cat. It went on for about 10 thousand miles, it would never happen when I brought the RV in to Freightliner. Well it turned out that the squeal was the idler pully on the waterpump belt. On the Cat., the waterpump is operated by a seperate "V" belt with an idler pully which serves as the belt tightner. It was an $80 part and took about 20 min to replace. The pully has a double bearing and when looking at it from the front of the engine, the outer bearing was visably shot. Luckily it was noticed while sitting in my yard and not along side the Interstate out in the middle of nowhere.
Good luck wgojerry

[Gary RVRoamer]

a/c compressor drive belt?

[RBK394]

Had a squeal on my ISL 400 in 07 Winnie Vectra. As you described, it squealed on acceleration. Thought for sure it had to be turbo. While on the road, and after paying a never used before freightliner dealer over $200 to tell me it was the alternator, I asked them if they pulled the belt to see. The answer was no. Tried to get my $200 back and essentially told to hit the road. Limped home and took to trusted freightliner dealer (Cruzans Freightliner in Bridgeton, NJ). Immediately, I was told that it was an exhaust manifold gasket leak. Replaced (under Cummin's warranty) and problem solved. Good luck.

By the way, tried to no avail to get freightliner to make the errant dealer account for my $200. I will forever be more inquisitive about a dealer's diagnostic approach.