A7 BiTDI Turbo failure

Eric_BiTDI

A7 S Line BiTDI
Hi guys, recently purchased a '12 plate A7 BiTDI due to needing a big comfy auto but with a bit of power and I have always liked the look of the A7 so jumped in. I did have a friend who I have known for over a decade, and had trusted him with his previous work, put a generic flash map on it soon after I purchased it. This was the only power/engine modification that I had done.

Fast forward five months and I hear a loud whine under acceleration (not the wife) and low ish power.. still drives okay with zero smoke or lights on the dash or DTCs stored.
I like to tinker with cars and have about average knowledge so thought I would take a brief look for any obvious issues with the intake / turbo side of things.

The airbox and intake pipe looked fine and no holes or damage, so I look into the turbo and see this...

Turbo fail.jpg



As you can imagine my heart sank.

So.. I have had that map taken off, had two people out to check it.. both say different things. Personally I feel it has over-boosted and possibly fouled the inside of the housing, there is a bit of play in the shaft.

I have explored a few options, Audi would like £4,850 JUST for the turbos. That is a no go.

Company I got the A7 from say use the Warranty, but I've looked into it and long story short - useless.

The only option for me is to pay myself. I have purchased a very low mileage second hand BiTDI turbo setup, all other gaskets I'd need from Audi too.

I'll get this fitted by a professional, all checked over and also having a Wagner intercooler fitted too. Once this is sorted I'll be heading down to the Legendary BSR for a few power additions.

I am not looking for diagnosis or being told off for generic maps, just sharing my experience so far!
 

rjwojcik

Registered User
Bad luck bud.

Do you think the map caused this? Could have been down to old age? How many miles and was it serviced well?
 

Eric_BiTDI

A7 S Line BiTDI
Personally I think yes the map but as always, can never prove anything really. I don’t think it’s down to old age mate no, serviced well even transmission serviced too, 90k miles it’s done.
 

RAF_S7

Well-Known Member
Gold Supporter
For that much damage I’d say oil starvation or a failure upstream in the air intake side.

I’d personally be very surprised if the map caused this, too much physical damage on the impeller tips.

With that much metal missing from the impeller, you need to be careful that nothing has been ingested into the engine and caused/could cause further internal damage :concern:
 

Eric_BiTDI

A7 S Line BiTDI
I agree with you @RAF_S7 about possible failure diagnosis. There’s just no evidence of anything hitting it ... but it looks like it has?! just very hard to pin point the issue. It could be a variety of things.

It’s all going to be stripped and checked for debris properly - hoping the intercooler has caught most of it.

Good excuse for a Wagner and further tuning:whistle2:
 

Eric_BiTDI

A7 S Line BiTDI
Looks like debris in the induction did that .

What air filter are you running ?

agreed mate it does look like it - but the intake and airbox and air filter all checked and nothing is missing or broken off.
Fully standard that side of things mate.
 

Eric_BiTDI

A7 S Line BiTDI
Cool , aftermarket don't filter well at all and will result with your type of compressor wheel damage.

Ah okay, I didn't know that. Yeah I looked at it and compared it to standard when I got the aftermarket filter out, it seemed a poor fit so chucked it back in the box.
 

Eric_BiTDI

A7 S Line BiTDI
I mean performance aftermarket filter K&N etc filter very badly for no or very little gain .
Yeah I know a lot of people fit them for sound purposes only, but as i have the active exhaust that is enough for me (plus I have the Kufatec sound booster coming)
 

bobby singh

BSR
VCDS Map User
Gold Supporter
Something has been sucked
I've got a CDUC in at the moment for some hybrid work with full Audi history and the Audi box has a missing O ring.With only 60k on the clock the turbo is ruined.
Im putting on a VZK hybrid so doesn't matter too much but goes to show all seals and O rings are there for a reason.

Just check your turbo in take pipe for holes - plus clean out all the charge pipes and wash out the intercooler. You may find whatever got sucked in and caused all this damage.
 

Eric_BiTDI

A7 S Line BiTDI
Hi @bobby singh, I'll re check the airbox / air filter again and see if i can find anything.

All intake pipes will be checked and flushed out and just ordered the Wagner with you to replace the standard intercooler.
 

Eric_BiTDI

A7 S Line BiTDI
Just a closure on this thread...

Turbos were replaced, intercooler replaced and all hoses and pipe work checked and cleaned out. Engine oil flushes etc etc. All running fine and now with the added touch of a BSR remap and transmission update.

Running sweet and plenty of boost now.
 

rjwojcik

Registered User
Just a closure on this thread...

Turbos were replaced, intercooler replaced and all hoses and pipe work checked and cleaned out. Engine oil flushes etc etc. All running fine and now with the added touch of a BSR remap and transmission update.

Running sweet and plenty of boost now.

Good news... Same turbos?
 

RAF_S7

Well-Known Member
Gold Supporter
Glad you got everything sorted in the end.

Did you ever get a root cause identified, or was it put down to a bearing failure?

John:racer:
 

Eric_BiTDI

A7 S Line BiTDI
Glad you got everything sorted in the end.

Did you ever get a root cause identified, or was it put down to a bearing failure?

John:racer:


Never did get a definitive answer - I've just put it behind me and forgot about it. I sold the turbo to someone for tuning R&D.
 

desertstorm

Moderator
Staff member
Moderator
VCDS Map User
Looks like overspeeding on the turbocharger probably due to ambitious boost requests. The compressor wheel is designed to operate within a certain RPM range. Outside of that forces acting on the wheel can literally tear it apart, when it's rotating at 180K RPM plus the forces exerted on the thin aluminium are very high. Thanks for posting and more so for finding the best solution to remapping. Somebody who knows a lot about the engine and knows what they are doing. Cheap remaps may look good but the cost of failure certainly outweighs the cost saving.
You could have had the original rebuilt with some hybrid wheels and then gotten Bobby to map it :).
https://www.melett.com/technical/why-turbos-fail/overspeeding/
 
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