What did my turbo crack?

[goodbuzzman1]

So as you may or may not know, I sent my turbo off to be reconditioned only to be told the housing was cracked. So I have sourced a new turbo and will be fitting it soon however,

the guy who was talking to me about the turbo said that it cracked possibly because of something to do with the cat? Something about not enough flow causing the turbo to heat up and crack? Is this a possible cause? I just want to make sure before I take the cat out as all the downpipe to cat bolts are non existent due to rust and will have to be cut off


im also replacing the egt sensor as this kept throwing up faults codes. Could this contribute?

 

[<tuffty/>]

They all crack... you need to be more specific...

What model/year would help as it could be one of at least four variants of turbo... the conditions vary but all K03/K04 turbos on these engines will end up with cracked hotsides... the amount of cracking depends on certain conditions.. and the model/year of car can contribute too as some are more susceptible than others

The guy you were talking too is kinda talking nonsense for the most part... these cars are designed to run CATs... VAG spent a ton of cash developing them... thats not to say it can't contribute under certian conditions but without knowing the spec and condition of the rest of your setup he is clutching at straws..

On S3's for example downpipes are more restrictive than CATs... on AMK/BAM engine codes VAG run these at lambda 1 too so they run hot as standard... poor mapping can increase heat and promote cracking... too many variables to single out a component...

<tuffty/>

 

[goodbuzzman1]

Thanks for the reply. It's a big standard bam s3 with a k04-023. He said the turbine housing was cracked.

 

[<tuffty/>]

They do... without pics I couldn't tell you if its unservicable or not but they all crack... worst ones crack by the turbine and where the wastegate penny seals

Again... not enough info tbh... mods, mapping etc... as I said, difficult to point the finger without further info but AMK/BAM run lean as std... bad maps add boost but no fuel and this makes then run hotter and will crack more readily...

<tuffty/>

 

[goodbuzzman1]

My s3 is pretty much standard in terms of hardware and the guy I bought it off didn't say it was mapped or anything.

 

[<tuffty/>]

Doesn't mean a lot mate... had one guy on a dyno day say the same and turns out not only was it mapped (badly) but hit over 25psi on a standard engine!!...

That will ****** a turbo (and rods) fairly quickly

<tuffty/>

 

[goodbuzzman1]

Is there any way it can find out if my car is mapped?

 

[<tuffty/>]

Log it in VCDS to see what the boost/airflow is doing, fit a boost gauge (can be temporary) or if you have an Android phone, use the Torque app to see what airflow/boost is... std S3 runs to around 0.8bar or 12 ish PSI

<tuffty/>

 

[Clart]

Doesn't mean a lot mate... had one guy on a dyno day say the same and turns out not only was it mapped (badly) but hit over 25psi on a standard engine!!...

That will ****** a turbo (and rods) fairly quickly

<tuffty/>

I think that was me... I'm booked in this month at Badger5 to get it correctly mapped...