Turbo

[Tuzlo]

What are the symptoms of a turbo failing?

For a while now I have been hearing squealing comin from the engine compt, but its never persistent. Couldn't even get it to make a peep when me and Fyrman took it for a spin one day. It does seem that there is a lack of power, but like the noise is not constant. What could cause this other than the Turbo?



Forgot to mention, NO codes thrown.

 

[Bmarc]

Belts? They like to squeal randomly.

 

[kburrell]

Didn't you have a turbo replaced a short time ago?

True turbo failure is really not that common. The dealerships quite often replace the turbo at the first sign of power loss rather than look for the true cause of the problem, ie. MAF, N75, vacuum leaks,etc. Turbo failure generally is preceded by significant lack of power (limp mode) and normally accompanied by loud sounds as turbo self destructs.

What you are describing sounds like a belt or bearing, Check the alternator pulley, A/C clutch, and serpentine belt. Spray the belt with belt dressing and see if that makes it go away. If so this is only a temporary fix, then replace the belt.

 

[-=PYRO=-]

You said it seems like there's a lack of power...are you certain? That problem thats not always there is always a bugger. Obviously its a moving part, so I'd say its a bearing in one of the pulleys starting to wear. I guess just wait until it does it again and try to locate the coulprit. I wouldn't think its the turbo though because I think it would be more consistant and noticeable.

 

[skenny]

I'm here to back up that when the turbo starts to go, there's typically boost problems like strange fluctuations or sustained boost, and the computer is usually smart enough to turn it off (limp mode).

 

[Slave2school]

Hmm my turbo made a long and slow death that started making it sound like a metallic ambulance siren at low rpm. When I knew it was really gone I was using 1L/100km of oil...

Clean the usual suspects to see if it is making the turbo behave badly (n75, check hoses for cracks or frays, check vacuum canister for leaks, check for free movement of the vnt actuator). You can even take off the turbo inlet pipe and give the turbo a wiggle. If it moves by any amount that you can feel more than say .5mm-1mm, then start saving pennies up.


You also have that fancy kp39...never played with an actuator on them (with the LVDT? looking device).

 

[gforce1108]

My 04 started making a very high pitch squeal yesterday. First I thought it was the radio since it would only make the noise for a split second. After it made the noise a couple more times I pulled over to give things a quick check. Nothing obvious and the oil level is right where I filled it to 2k ago with Elf 505.01.
I can now repeatably make the noise at low RPMs, with a very light throttle. Any more or less and it goes away.
No drivability issues. Sounds metalic, not RPM dependant exactly - more throttle position or maybe boost dependant. Also sounds much higher pitched than any bearing I've ever heard, but I won't rule anything out yet.
Got to get it in the garage to check turbo play and everything else mentioned above.
It'll probably be this weekend that I can inspect (hopefully it lasts that long!) and I'll post and update

 

[gforce1108]

I just searched through a ton of old posts and found a couple with similar squeals. One was a cracked EGR line and others were boost leaks.

 

[Tuzlo]

Kburrell

Yes Hillcrest replaced my turbo, and I think they messed up when they did cause I had it back in the same day in lmip mode and they replaced a vaccum line.

I seriously need someone to show me how these engines work, I have no idea where N75, MAF or any other of the pieces are or how to check them. I thought it was a belt pulley, but like I mentioned it has a lack of power, but I can overcome that by gettin the revs up higher.....


Totally Confused.

 

[gforce1108]

If you follow the vacuum line from the turbo actuator back, it will run to the N75 valve. It's on the firewall near the middle of the car.
The MAF is the part connected to the air filter housing. There is one electrical connector on it. It will throw a code if you disconnect it, but will help diagnose a bad MAF.

 

[gforce1108]

I found the source of my high pitched squeal over the weekend. The oring on the intercooler tube where it attaches to the throttle housing had pushed out and broken. The boost was leaking out of the little slit that the retaining clip sits in. I picked up a NAPA oring part number 1108 and squeezed it in there.
I did find out why it pushed out too. I drilled and tapped holes and use set screws to keep the intercooler tube from constantly popping out of the housing, but I only put two about 120 degrees apart on the top. This pushed the tube down and let the oring slip out. I pulled the housing and added another set screw to the bottom to keep it centered. Plus, this new oring is quite a bit thicker.