# Bad turbo bearing?



## Blasirl (Mar 31, 2015)

machusenpai said:


> Alright guys, a couple of weeks ago a sound started getting worse at idle and when rev (did not matter if I was accelerating or not, maybe a tiny bit louder in gear?) and it sounded like a small police siren, now the sound had gotten way worse and people were staring at me and I got tired, I asked a mechanic and he said it was the turbo. I took the DPF out and tried to inspect the turbo. The sound with the exhaust on sounded like a police siren (not a turbo spooling, I know the differences) but now without the exhaust it sounds like a screeching and its even worse if the engine is cold. During a cold start there is a lot of blue smoke and the screeching is at it worst. Is this a bad turbo bearing? There isn't really a play but the turbo seem to be a bit "hard" to turn sometimes?
> 
> Here is the video but it doesn't seem to catch the screeching tbh in person the screeching is bad:


1st - Stop revving the engine and for that matter don't start it until you figure out what it is. at first it sounded like a knock sensor.
To be safe I would drop the exhaust and pull the turbo and look at it and spin it by hand.

FYI: Blue smoke is a strong indication that oil is burning


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## machusenpai (Jun 24, 2021)

Blasirl said:


> 1st - Stop revving the engine and for that matter don't start it until you figure out what it is. at first it sounded like a knock sensor.
> To be safe I would drop the exhaust and pull the turbo and look at it and spin it by hand.
> 
> FYI: Blue smoke is a strong indication that oil is burning


I haven't had time to work on it that much but what do you mean by knock sensor? Also, can a turbo be bad if there is no shaft play?


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## Blasirl (Mar 31, 2015)

machusenpai said:


> I haven't had time to work on it that much but what do you mean by knock sensor? Also, can a turbo be bad if there is no shaft play?


I am not sure the diesel has one, but the knock sensor picks up vibration and sound coming from the engine block, turns it into an electronic signal and sends that signal to the engine control unit (ECU). The car's computer then judges the information and determines whether or not ignition timing should be altered.

@Snipesy


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## Snipesy (Dec 7, 2015)

It’s possible. Shaft play tends to mean complete failure of the bearing… But if the bearing fails more gradually there may be no play.

There is also the VGT actuator, the ‘device’ those hoses hook to, which can make noise when it starts to fail, but not quite like that.
More about that here https://static.nhtsa.gov/odi/tsbs/2014/SB-10072144-0335.pdf


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## machusenpai (Jun 24, 2021)

Snipesy said:


> It’s possible. Shaft play tends to mean complete failure of the bearing… But if the bearing fails more gradually there may be no play.
> 
> There is also the VGT actuator, the ‘device’ those hoses hook to, which can make noise when it starts to fail, but not quite like that.
> More about that here https://static.nhtsa.gov/odi/tsbs/2014/SB-10072144-0335.pdf


Well, this is literally straight pipe in the video, with the dpf on it is more like a siren.


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## TheRealHip (Sep 1, 2014)

Could a plugged dpf do that?


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## machusenpai (Jun 24, 2021)

TheRealHip said:


> Could a plugged dpf do that?


The dpf was removed in the video.


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## TheRealHip (Sep 1, 2014)

The noise was when the dpf was in it not after it was out........


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## Snipesy (Dec 7, 2015)

TheRealHip said:


> Could a plugged dpf do that?


Plugged dpf just makes the engine stumble at low speed or not start at all. Not too dissimilar to plugged EGR. At higher speeds a plugged dpf rarely makes a difference… Akthough obviously you would have REP.


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## machusenpai (Jun 24, 2021)

Snipesy said:


> Plugged dpf just makes the engine stumble at low speed or not start at all. Not too dissimilar to plugged EGR. At higher speeds a plugged dpf rarely makes a difference… Akthough obviously you would have REP.


My EGR is definitely clogged. If I open my egr at 50% the car wants to die.


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## machusenpai (Jun 24, 2021)

Snipesy said:


> Plugged dpf just makes the engine stumble at low speed or not start at all. Not too dissimilar to plugged EGR. At higher speeds a plugged dpf rarely makes a difference… Akthough obviously you would have REP.


Snipesy! You're a real pro when it comes to the Cruze Diesel and I was wondering, can I just change the CHRA cartridge in my turbo? If yes, do you have any links or part number?


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## Snipesy (Dec 7, 2015)

machusenpai said:


> Snipesy! You're a real pro when it comes to the Cruze Diesel and I was wondering, can I just change the CHRA cartridge in my turbo? If yes, do you have any links or part number?


You won’t get it from GM… I’ve never torn apart a turbo annnd most likely never will.



https://m.aliexpress.com/item/1005002566516833.html?trace=wwwdetail2mobilesitedetail



I don’t even know if that’s the right one.


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## DmaxMaverick (Jun 29, 2014)

Diesels burn oil. Diesels knock (no knock sensor). That's what they do. Oil is fuel, to a Diesel engine. If you're getting blue smoke and the engine is holding idle and not complaining (SES lamp), the oil is entering the exhaust, and not going through the engine. Turbo oil drain blockage can cause an oil leak and smoke (it's a zero pressure drain to the sump), but will be silent, in itself. Noise + exhaust oil leak = kaput turbo. It doesn't take much turbine radial play to cause the spindle bearing to chatter, which could be part of the noise you're hearing. End play is different, with an acceptable amount. Nearly any side (radial) play is not acceptable. DO NOT run the engine until this is corrected. If the compressor wheel is contacting the housing, at all (another possibility for the noise), it will send metal into the engine. You cannot (successfully) replace just the spindle shaft bearing. The spindle will likely need to be replaced, and any turbine or compressor wheel contact will require their replacement. It's best to just replace the turbo with a good reman.


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## machusenpai (Jun 24, 2021)

DmaxMaverick said:


> Diesels burn oil. Diesels knock (no knock sensor). That's what they do. Oil is fuel, to a Diesel engine. If you're getting blue smoke and the engine is holding idle and not complaining (SES lamp), the oil is entering the exhaust, and not going through the engine. Turbo oil drain blockage can cause an oil leak and smoke (it's a zero pressure drain to the sump), but will be silent, in itself. Noise + exhaust oil leak = kaput turbo. It doesn't take much turbine radial play to cause the spindle bearing to chatter, which could be part of the noise you're hearing. End play is different, with an acceptable amount. Nearly any side (radial) play is not acceptable. DO NOT run the engine until this is corrected. If the compressor wheel is contacting the housing, at all (another possibility for the noise), it will send metal into the engine. You cannot (successfully) replace just the spindle shaft bearing. The spindle will likely need to be replaced, and any turbine or compressor wheel contact will require their replacement. It's best to just replace the turbo with a good reman.


There is literally no shaft play, however the compressor wheel look like it ate some chunk of dust or tiny rock (the turbo is not from this engine, it was on another totalled vehicle and the dealer swapped it) but it didn't turn really good from what I looked. 2-3 seconds after the engine shutoff the turbine stop spinning really fast. I will be rebuilding it, not taking a chance. I removed the turbo and plugged the oil feed line and there is no blue smoke on start, which indicate that the turbo seals is kaput.


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