# TTRS Piston cracked



## ttrs stage3 (Apr 5, 2014)

Hi,
I had an intake manifold failure so air was going in in the engine after fixing the intake manifold the repairman tested the car ,while he was testing a piston cracked 

he told me there is only 1 piston cracked .
what do you guys recommend? 
1-change all the pistons and rods and install APR ?
2-chane only 1 piston with a new oem?
3-change all pistons with new oem?


i want to change all pistons and rods to apr since he is going to open the engine but i am not sure he will fix it 100% like APR standard so i am bit worried 
is there a book with APR to instruct the repair man how to fix the engine?
thanks


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## CarbonRS (Jul 15, 2013)

APR pistons require a larger bore, something you may not want them doing. Did the engine ingest something when they were fooling around with the intake manifold? You may need to re-bore the cylinders anyway if so. This doesn't really make any sense.


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## Marty (Jul 14, 2000)

I would reach out to APR on that one. Why is the piston cracked would be my first question.


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## ttrs stage3 (Apr 5, 2014)

Marty said:


> I would reach out to APR on that one. Why is the piston cracked would be my first question.


From the intake mainfold failure = Lean engine 
when i changed the intake mainfold it was too late


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## Marty (Jul 14, 2000)

ttrs stage3 said:


> From the intake mainfold failure = Lean engine
> when i changed the intake mainfold it was too late


What failed in the intake manifold exactly? I'm surprised the knock control didn't save it.


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## jaybyme (Aug 29, 2012)

I agree,seems very strange that no warning came up.
I would have the engine re-built


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## crew219 (Oct 18, 2000)

ttrs stage3 said:


> From the intake mainfold failure = Lean engine
> when i changed the intake mainfold it was too late


I wouldn't necessarily buy that explanation. 

Sure it wasn't the adjustable flaps that "failed"? Those fail in the open position anyways and wouldn't create a situation in which the piston cracks.


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## ttrs stage3 (Apr 5, 2014)

crew219 said:


> I wouldn't necessarily buy that explanation.
> 
> Sure it wasn't the adjustable flaps that "failed"? Those fail in the open position anyways and wouldn't create a situation in which the piston cracks.


i really dont know i sended my car to the mechanic to check some high rpm hestation and power cutoff 
later he called me and he said intake mainfold failure from the gasket and rubber and when he repaired it he drove the car to test it a piston cracked


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## carl44 (Nov 23, 2012)

Something doesn't add up get another opinion. Its highly unlikely that there isn't other collateral damage inside besides the piston. If it scored the cylinder wall the block maybe trash. sorry carl


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## crew219 (Oct 18, 2000)

ttrs stage3 said:


> i really dont know i sended my car to the mechanic to check some high rpm hestation and power cutoff
> later he called me and he said intake mainfold failure from the gasket and rubber and when he repaired it he drove the car to test it a piston cracked


Your mechanic's opinion doesn't make much sense. Perhaps the intake manifold was a misdiagnosis. If there was an air leak, besides idling like crap, the O2 sensor would be able to adjust fueling to ensure it doesn't run lean.


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## Fined (Sep 3, 2013)

maybe having an audi dealership look at the car would be a good option instead of guessing about it and potentially throwing more money at the wrong issue. having them diagnose the problem will be more costly than someone else, but you don't have to let them do the repair work. 

the whole thing doesn't sound very legit.


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## carl44 (Nov 23, 2012)

ttrs stage3 said:


> i really dont know i sended my car to the mechanic to check some high rpm hestation and power cutoff
> later he called me and he said intake mainfold failure from the gasket and rubber and when he repaired it he drove the car to test it a piston cracked


You really dont even need to drive a car to confirm a vacuum leak was fixed. Any scanner will read STFT's they should be around 0 . With a vacuum leak they go high because the ecu is adding fuel to compensate . carl


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## StefanP (Jun 8, 2011)

ttrs stage3 said:


> i really dont know i sended my car to the mechanic to check some high rpm hestation and power cutoff
> later he called me and he said intake mainfold failure from the gasket and rubber and when he repaired it he drove the car to test it a piston cracked


I had the same issue with hesitation under high load. Turned out to be a fuel pump issue, couldn't keep up with demand basically. New pump fixed it.


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## URHank (Mar 19, 2009)

Cracked piston? I highly doubt it. Yes, TTRS has a cast piston, but they are extremely tough units with an steel embedded top ring reinforcement. I have seen cracks, but those are only when rod bearings spin and put pistons into the head once the piston to head clearance of .035" has been eaten away by the bearing. 

Sounds extremely fishy to me. Where are you at and who is the shop?

Hank


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## JohnLZ7W (Nov 23, 2003)

I'm wondering how it was even diagnosed. They could do a compression/leakdown test to check for issues within a cylinder but they wouldn't know specifically that the piston had cracked until they tore the block down would they?


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## URHank (Mar 19, 2009)

I'd love to know more about this failed intake manifold too. 

Hank


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## MCPaudiTT (Nov 26, 2006)

JohnLZ7W said:


> I'm wondering how it was even diagnosed. They could do a compression/leakdown test to check for issues within a cylinder but they wouldn't know specifically that the piston had cracked until they tore the block down would they?


One could theoretically see it if they dropped a borescope in there... Who knows if that is the case, though...


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## Poverty (Feb 17, 2012)

It wouldnt be the intake manifold.

Either, fuel pump is faulty and not getting enough fuel which means it starts to run lean, or diverter valve was sticking and the engine started overboosting.


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## crew219 (Oct 18, 2000)

Poverty said:


> It wouldnt be the intake manifold.
> 
> Either, fuel pump is faulty and not getting enough fuel which means it starts to run lean, or diverter valve was sticking and the engine started overboosting.


If the DV was "sticking" it wouldn't matter since the ECU cuts N75 simultaneously.


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## Poverty (Feb 17, 2012)

crew219 said:


> If the DV was "sticking" it wouldn't matter since the ECU cuts N75 simultaneously.


True but this is stage 3, on a stock turbo car it would drop into soft limp, but im not sure if it does on stage 3


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## Not4show (Jun 11, 2004)

ttrs stage3 said:


> Hi,
> I had an intake manifold failure so air was going in in the engine after fixing the intake manifold the repairman tested the car ,while he was testing a piston cracked
> 
> he told me there is only 1 piston cracked .
> ...


TTRS---If I remember correctly you are in the middle east and have APR stage 3 on your car. You also had previous issues with the tune. I would get a hold of APR and find out who they want you to take the car to, to look at it. If your car is already at the tuner shop that did the install or that they recommend, I would take it to the Audi dealer to diagnose the issue.

I have not seen a car "crack" a piston from a lean condition, that was only test driven. I have seen blown headgaskets warped heads, bad rings and numerous things, but the piston is pretty stout and rarely is there an issue itself unless there is something ingested into the engine that physically damages the piston...........nuts, bolts, sockets, washers.........

But, the first thing I would do is verify that there is oil in the car and what the oil pressure it.


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## Dan.S (Jan 3, 2012)

Hows this for a piston..... My other car lol.


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## ttrs stage3 (Apr 5, 2014)




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## [email protected] (Dec 14, 2012)

Poverty said:


> True but this is stage 3, on a stock turbo car it would drop into soft limp, but im not sure if it does on stage 3


APR Stage 3 TT-RS has an overboost protection mode. A stuck DV would probably be able to activate it.


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## URHank (Mar 19, 2009)

Odd failure. I have seen this in FSI engines where high EGTs will expand the tops of the pistons to the point where you lose the ring gap in the OEM top ring and it rocks the piston enough to crush the lower skirt. 

Was this car stage 3 when the damage happened? What kind of boost pressures and what fuel?

Hank


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## nzt (May 24, 2012)

Kuwait?


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