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Discussion Starter · #1 ·
89 TTA. 42k, Very minor non-stock parts, K&N, hotwired FP, Thrasher 93 MAF Translator, LT1 MAF, THDP.

Cold startups produce blue exhaust smoke for a couple miniutes. Does not appear to smoke on hot restarts. Does not smoke under boost.

PVC is clean and new, no oil in hose.
Valve cover breather hose at turbo inlet is dry (I think this is TTA only).

1. Oil found here:
1.1. Front face of throttle body plate.
1.2. Compressor side of Turbo inlet bell.
1.3. Heavy at top of intercooler to inlet pipe hose.

2. Other inspections completed:
2.1. Dial indicator on end of turbo compressor shaft = .024" up/down.
2.2. Side to side end play = .002".
2.3 Compressor vanes not touching housing, but mighty close.

3. Inspections I intended to do, until I detected the above .024":
3.1. Compressor check
3.2 Turbo drain tube for obstructions

I'm thinking a center section rebuild is in order for the turbo.
Your experienced feedback is appreciated.
 

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THE MILF MAGNET
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I have the same problem. Lets see what the gurus say. Come on guys, my neighbors are dying from smoke inhalation lol.
 

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How much in and out play on the shaft?...it should be almost imperceptible.

Sounds like it well could be the turbo to me...the other common cause are the valve guide seals.
 

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Discussion Starter · #5 ·
Steve Wood said:
How much in and out play on the shaft?...it should be almost imperceptible.

Sounds like it well could be the turbo to me...the other common cause are the valve guide seals.
Steve,

Side to Side end play is .002"

I intended to look at valve seals also, but stopped when I found the compressor side of the shaft had .024" movement up and down.
 

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Discussion Starter · #6 ·
earlbrown said:
Does the inside of the downpipe have oil in it?
Earl,

I have not removed the turbo yet. I suspect the center section should be rebuilt and I will remove the turbo this weekend. I'll find out then if there is oil in the downpipe.
 

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look at all hoses when mine leaked it had what i believe they call is coaking, its a dried brownish mess which is almost hard bout all that will take it off is gas the reason i state this is cause it doesn't feel like oil but it is, if you have this oil is coming out from somewhere (turbo, line from valve cover to inlet bell) can you get a flashlight and look at the bottom of the intercooler and see any liquid?
 

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Imiss#3 said:
Steve,

Side to Side end play is .002"

I intended to look at valve seals also, but stopped when I found the compressor side of the shaft had .024" movement up and down.
I asked about in and out play :) That is the critical dimension.
 

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Quick question

do you have a chrome filter on the passenger side valve cover?
if not get one, you are sucking crank gases and oil into your turbo inlet

also check your PCV valve

:6:
 

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Discussion Starter · #11 ·
Steve Wood said:
I asked about in and out play :) That is the critical dimension.
Steve,

Thanks for your help.

I thought I was was on the (2) dimensinal clearances that exist.
(1) Sided to side end play (along the axis of the centerline of the shaft) is .002". With a Dial Indicator on the end of the compressor nut, I pushed on the compressor wheel and then the turbine wheel. It moved .002".

(2) Radial clearance (up/down, fore/aft) is .024". I put the Dial Indicator on the top of the compressor wheel nut and pressed up and down on the compressor wheel. It moved .024". I put the Dial Indicator on the front of the compressor wheel nut (towards front of car) and pressed fore and aft. It moved .024".
 

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Discussion Starter · #12 ·
More_Boost!! said:
Quick question

do you have a chrome filter on the passenger side valve cover?
if not get one, you are sucking crank gases and oil into your turbo inlet

also check your PCV valve

:6:
Thanks for your input.

Turbo Trans Ams do not have a breather on the passsenger side. They suck from the driver's side valve cover. It's all clean and dry.
PVC and hose are clean and dry.
 

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Discussion Starter · #13 ·
onefastcar said:
look at all hoses when mine leaked it had what i believe they call is coaking, its a dried brownish mess which is almost hard bout all that will take it off is gas the reason i state this is cause it doesn't feel like oil but it is, if you have this oil is coming out from somewhere (turbo, line from valve cover to inlet bell) can you get a flashlight and look at the bottom of the intercooler and see any liquid?
Thanks for your help.

All hoses that have oil in them are on the intake from the turbo inlet bell all the way to the throttle body.

The coking you refer to is actually an issue that can cause your car to smoke. What happens is this; the oil (usually non-synthetic) sits inside the turbo when you shut the car off. If you just beat the tar out of it on a hot day, the turbo is hotter than hell. The oil sits in the turbo and basically bakes. Do this enough times and it can eventually create a blockage in the oil drain out of the turbo. If the oil has a hard time draining it build pressure and the oil is forced past the seals. You now have a smoker.

My drain and turbo are very clean. It apears to be prematurely worn bearings.
 

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Discussion Starter · #14 ·
Smoke at startup gone.

Update.

I rebuilt the center section. The bearings (aluminum) had minor wear. Smoke is gone.
 
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