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S4, turbo failure

Posted: Tue Jun 02, 2009 7:53 pm
by MarkHanman
Recently bought a S4, Sreg. Still awaiting v5.
It's in Audi for some remedial work now on the turbo's, while I'm away.
Is there anything else that I should get done while it's apart?
Heatshields may be being attended to, as at least one of these has a rattle.

On the test drive, power was good. Car generally very tight for 95k miles. Only the heatshield rattle in evidence.
The turbos were replaced in Mid2008 (independent garage, using Audi TPS facility). On the history, the right hand turbo developed a fault soon after, and was replaced by Audi under warranty.
Now the left is making some horrible whines when boost is up. Back to audi for warranty replacement.

Is there some history with the 03 turbos, and short life expectancy?

Re: S4, turbo failure

Posted: Tue Jun 02, 2009 8:14 pm
by Blue_Thunder
MarkHanman wrote:Is there some history with the 03 turbos, and short life expectancy?
More than you can shake a stick at.

Multiple failures probably point to another fault on your car, eg: Boost leaks, fauly MAF causing lean running and high EGT's, overboosting, blocked oil feeds, etc.

It's one of the many reasons most people in a similar situation upgrade to the larger K04 turbos (standard fit on the RS4).

RE: Re: S4, turbo failure

Posted: Tue Jun 02, 2009 8:23 pm
by MarkHanman
I've been thinking about the K04. These 03s are new, and I just need the car for banging up and down the motorway. Once the turbo's been replaced, I'll get it back in to the other place for a service and check over. The car won't be used a huge amount. 1 month out of 3 max.
I'm battling with mobile broadband, so pages are slow to load sometimes. makes searching awkward.
Cheers.

Posted: Wed Jun 03, 2009 7:28 pm
by MarkHanman
What are the primary causes of K03 failures, other than external factors? What is the inherent weakness?

nb.
MAF is listed as replaced.
Oil feed lines replaced.
Top end rebuild done.
All by a respected tuner/specialist

Posted: Wed Jun 03, 2009 8:22 pm
by Blue_Thunder
Clicking on 'Search' and putting in K03 Failure brought back shed loads of pages.

This was the 2nd or 3rd one down (titled "What caused your K03's to fail?") - http://www.rs246.com/index.php?name=PNp ... 03+failure

Posted: Thu Jun 04, 2009 8:36 am
by Blue_Thunder
Have you been letting the oil temperature rise before driving the car hard and have you also been allowing it enough time to cool down before turning the engine off?

If you don't do the former, you can damage the bearings in the turbo as they spin at well over 100,000rpms, so plenty of lubrication is needed!
If you don't do the latter, oil can 'cook' inside a glowing hot turbo when you turn the engine off and cause blockages leading to oil starvation.