Noise from turbo ???

[Terry King]

Hi
I have a problem with a 2001 2500HD Duramax/allison crew cab.
I have a very occasional harsh engine noise early mornings when going to work that I have not bothered to look into until now.
This has gone on for 18 months & only happens once or twice a month.
After leaving our driveway it normaly ends & drives normaly after the first intersection a mile down the road.
During this time it is down on power & emits a harsh sound which I belive is a turbo or wastegate malfunction.
last week it lasted longer & I really noticed it when passing a car (no power) a bit scarry.
Later that week we towed a race trailer on a very hot day on a 3 hour trip where we noticed the harsh sound & power loss on a couple of occasions going through towns.
At the end of the trip we climbed a series of hills & the engine sounded to rev with a lack of power while in low gears as though the turbo was not working.
On the jouney home it was cooler & no sign of any problem.
My question is: has anyone had or know of this problem with a Duramax.??
Is it Turbo, wastegate, computer control, or something else. ??
Hoping someone can shed some light on this problem.
regards Terry.

[Claven]

It almost sounds like it could be your engine fan, it can stay locked up in the mornings and it does rob some power aswell as making the engine sound like it's reving higher, it will lock up when its hot out,have you had the truck since new and is this noise new to you? Other than that maybe check your clamps on the intercooler lines, mine were leaking with a loud whistle even though they felt tight they were'nt. Any way to monitor your boost pressure? see if it makes the noise at a certian pressure?.........I just read your post a little closer and I would have to say its just your cooling fan coming on, they make a loud high wind type noise, kinda hard to describe other than a shrouded fan haulin ass. and they lock up when engine is cold I think to put a load on the engine to assist in warmup.

[ 02-16-2006, 09:17 PM: Message edited by: Claven ]