Intermittent Turbo (deep throaty) Sound??? [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: Intermittent Turbo (deep throaty) Sound???


Brancieri
01-29-2007, 01:39 AM
2006 LLY, truck is warm and I stop at the store or for gas or even stop at work for a little while, start the truck and take off and I hear a deep throaty sound from the turbo, which does not seem normal. When I restart the truck it continues for a few minutes and then goes away. My check engine light has come on and the dealer had to order a part, some kind of turbo actuator or something like that. But, this sound has happened even before the engine light came on. When I mentioned the noise to the service writer he insisted it was the cooling fan...It's not. I know what the fan sounds like and it's definitly NOT the fan. It doesn't happen very often. Recently I was towing my toy hauler, stopped for fuel (kept the truck running while fueling) when leaving the gas station it came on again. Only for about 3-5 minutes, but it doen't sound normal. Any suggestions?

Thanks

Senotext
01-29-2007, 02:43 AM
I think what you are hearing is just that vane position changing on the turbo, my truck does this all of the time, no worries man, its normal, it goes from sounding like a jet to sounding like a big block right?

Senotext
01-29-2007, 02:44 AM
BUT, mine only does it at idle or just off idle for a maybe a second or two.

MGlickLBZ
01-29-2007, 10:46 AM
Have they put the new part on yet?

Brancieri
01-29-2007, 10:46 AM
Yeah...it sounds like a jet turbine, lasting a minute or two, sometimes a few. I didn't think it was a big deal, but wanted to double check. Thanks.

Brancieri
01-29-2007, 10:47 AM
No new part yet. Waiting for it to come in.

saratoga
01-29-2007, 11:36 AM
It sounds like you're hearing the clutch fan (engine cooling fan). Normal for it to be engaged when cold, but mine has never engaged after a warm re-start.
The fan on these trucks is so big and moves so much air, it sounds like a 747 taking off. May not be normal if it's engaging when you re-start after it's warmed up.

Smokin06LLY
01-29-2007, 11:50 AM
It sounds like you're hearing the clutch fan (engine cooling fan). Normal for it to be engaged when cold, but mine has never engaged after a warm re-start.
The fan on these trucks is so big and moves so much air, it sounds like a 747 taking off. May not be normal if it's engaging when you re-start after it's warmed up.


I just got my new truck on Wednesday and my clutch fan seems to engage all the time - even after the engine is warmed up. It was around 40+ degrees when I test drove it (only heard the fan for the first few miles - what I would consider normal). Since I picked it up, it's been no higher than 35 degrees and a couple of days it was only in the teens.

MGlickLBZ
01-29-2007, 12:53 PM
No new part yet. Waiting for it to come in.


If it is the actuator, that might have something to do with it. Re-post when you get it fixed and let us know if it fixed it.:)

DSTEVENS
01-30-2007, 08:41 PM
I dont know about 06 model, but I have 07 and at idle, and some times under part throttle you can here a very noticable change in exhaust note, it only lasts a few seconds, but lots of people comment on it if we happen to be standing near the tail pipe, I have heard it is normal, go figure.
David

Brancieri
01-30-2007, 11:46 PM
The dealer replaced the part on the turbo this morning. It happened once for a moment, but as I said it is very intermittent. I can go a few days and not hear it. I'll keep everyone posted. Not exactly what they replaced on the turbo but it was directly connected to the side of the turbo itself. I'm not happy with my dealer at all. They didn't fully tell me what the part does. That's not why I'm not happy, but that doesn't help my opinion of them.

FASTOYS
01-31-2007, 07:27 AM
I believe the noise you are hearing is the variable vane turbo changing vane positions! It is normal.

Vege-Taco
01-31-2007, 08:48 AM
Mine seems to only do this within a few seconds of starting up the truck. After the truck has run for awhile I don't hear the exhaust note change while idling. It's most likely an EGR emissions related turbo vane thing.