Abnormal 'whining' noise from turbo under boost

[tunersteve]

For the past two weeks or so, I have noticed that when I start my car up, as the car is warming up, any time I go close to WOT and am under boost, the car makes a whining noise. The best way I can describe it is similar to a supercharger type whining. After the car warms up, the noise goes away.

I have had the MS CAI and Cobb TIP on for some time, and this has been only recently. I have checked all of my intake connections, as well as the inlet connection to the turbo, as well as look for any holes/wear signs on the silicone sections. Also, the car still sees normal boost pressures. I am able to hit and hole 18.5+ psi any time.

The turbo was replaced in April of 2009 with a newer revision model, and haven't had any issues to date.

I think my next step is going to be removing the whole intake system and inlet and checking the compressor wheel of the turbo itself, to make sure it isn't damaged at all.

Any thoughts as to what this could be? Any other potential areas to check?

 

[BoostedSpd6]

what about vaccum lines??.. thats the only thing i can think of besides checking the Wheel..

 

[tunersteve]

I'll look at that Tuesday when I tear the intake out. I checked the boost control solenoid lines back near the turbo and they were all intact. Besides, it only does it for a few minutes, then goes away, which makes it odd to me.

 

[BoostedSpd6]

I'll look at that Tuesday when I tear the intake out. I checked the boost control solenoid lines back near the turbo and they were all intact. Besides, it only does it for a few minutes, then goes away, which makes it odd to me.

that is odd..subbing for results on Tuesday.

 

[zinger002]

is it speed sensitive? like under a different pressure its quieter or does it only exist at almost wot?

 

[tunersteve]

is it speed sensitive? like under a different pressure its quieter or does it only exist at almost wot?

Only at near WOT/WOT when the car is first started. Usually 2-3 minutes and it goes away.

 

[Super Shredder]

driving belt.

 

[tunersteve]

driving belt.

I didn't realize our turbos are belt driven...

I just drove it again. It's pretty loud,and only under boost.

 

[BoostedSpd6]

I didn't realize our turbos are belt driven...

I just drove it again. It's pretty loud,and only under boost.

(lol)

 

[Blendercloud]

Sounds like a bearing issue. This is why:

Whining happens only when:

Car is cold.
- The bearing isn't able to be properly lubricated. Obviously the oil is thicker at this point and not able to penetrate every nook and cranny. Not to mention there are still numerous thermal expansions taking place.
Only happens under boost.
- The cold side of the turbo isn't under load otherwise.
Only happens at near-WOT or WOT when the engine is cold.
- I highly recommend you stay under 3,000 revs until the car is properly warmed. Cold high-revving can result in greatly-accelerated wear of the main bearings.


Since the sound goes away after it warms, it may just be a design issue of the turbo and/or the oiling system. It also may be an issue with the type of oil being run, the way the car has been driven, or possible oil contamination. I'm interested to see what comes of this. If you don't let your car idle for a couple of minutes when it's below 60F, I encourage you to start.

 

[all4bspinnin]

^this...

 

[zinger002]

^this...

informative post.

lol i was like driving belt? how about timing belt? oh wait lol. (ugh) (outie)

good luck on the repairs sir steve.

 

[all4bspinnin]

informative post.

lol i was like driving belt? how about timing belt? oh wait lol. (ugh) (outie)

good luck on the repairs sir steve.

Ya, i was showing that i agree'd with cloud...

Anyways, let me ask this... have you done any downpipe or exhaust manifold work recently?

 

[BoostedSpd6]

ill be putting both of those in this afternoon when ups shows up with them..what do u need to know specifically.. pm me ok.

Blendercloud i didnt even begin to think about the bearings.. slipped my mind, very informative post..

 

[tunersteve]

Sounds like a bearing issue. This is why:

Whining happens only when:

Car is cold.
- The bearing isn't able to be properly lubricated. Obviously the oil is thicker at this point and not able to penetrate every nook and cranny. Not to mention there are still numerous thermal expansions taking place.
Only happens under boost.
- The cold side of the turbo isn't under load otherwise.
Only happens at near-WOT or WOT when the engine is cold.
- I highly recommend you stay under 3,000 revs until the car is properly warmed. Cold high-revving can result in greatly-accelerated wear of the main bearings.


Since the sound goes away after it warms, it may just be a design issue of the turbo and/or the oiling system. It also may be an issue with the type of oil being run, the way the car has been driven, or possible oil contamination. I'm interested to see what comes of this. If you don't let your car idle for a couple of minutes when it's below 60F, I encourage you to start.

You've pretty much reaffrimed my first thought. My main concern is that there isn't bearing/shaft damage to the turbo. I usually go easy on the car until its warmed up, but I began noticing this when I tried to get into boost a little quickly. Since then, it's been a repeat issue on startups.

Ya, i was showing that i agree'd with cloud...

Anyways, let me ask this... have you done any downpipe or exhaust manifold work recently?

No exhaust work, just a test pipe.

 

[Blendercloud]

Further to my first post...

Steve, if you are putting your car back to stock to head to the dealer, I think you'll probably want to leave the car there overnight and let them start it the next morning (since it's cold; obviously). You may end up getting a third turbo for your car!

 

[tunersteve]

Further to my first post...

Steve, if you are putting your car back to stock to head to the dealer, I think you'll probably want to leave the car there overnight and let them start it the next morning (since it's cold; obviously). You may end up getting a third turbo for your car!

Definitely. I plan on taking someone from the dealer for a ride in it so that I can show them what I'm talking about and they can reproduce the problem. I hate to get another turbo, but if that's what it takes, so be it.

 

[all4bspinnin]

if i recall, i have heard of bad turbo's making a whurrrr noise... it was the compressor hitting the side of the housing.

 

[tunersteve]

Well everyone, took the intake and inlet out today.

First, I removed all of my intake piping all the way back to check for anything abnormal. Found nothing out of place. Checked the fins on the compressor side of the turbo, nothing worn or scored on the inlet of the turbo itself. Next, took the time to clean all of my intake piping, and check connections. I put everything back together. Made sure everything was lined up, then tightened everything back down. Made a few adjustments to the couplers, and realigned some of the clamps.

Took it for a spin and its all good. Also took the time to re-grease the Forge, and clean the TMIC up a little bit. So, in the midst of everything, it all worked out well.

I'll keep an eye on it through the week, but I'm pretty much calling this done.

 

[BoostedSpd6]

so it just needed a cleaning?? and a reinstall. well im glad its all working properly now..better then having to replace the whole turbo.