A5 3.0 TDI Quattro S-line - Coolant leak Porous heads (engine)

[leo1976]

Hi All

Advice or help needed, just signed up to this forum hoping someone may have heard or sadly experienced this before.  I have a A5 3.0 TDI Quattro s-line 242 bhp.  Recently just spent £2863 on having my gearbox fixed (sensor issue so took the gearbox out and fixed, replaced every nut and blot and put back together) by Audi in Newbury (last week) to only be told that upon inspection that the engine has porous heads in the engine due a coolant leak and Audi now claim that to rebuild it and fix will cost an extra £5250.  I actually want to die.  How can this be correct.  3.0 TDI engine V6 blah blah blah has only done 89K miles.  Has anyone heard of this before?  No idea what to do.  My wife laughing her head of at me saying you should not have bought the car earlier this year.  Christmas around the corner etc etc.  Any ideas welcome.  Thanks 

[Trevor]

Hi Leo....welcome to the Forum

I would take the car to a reputable garage who can carry out good old fashioned diagnosis on the engine/cooling system.

One test I would definitely get carried out is a block test (a test with a clear tube partially filled with liquid which then changes colour if there is combustion gas present) as this will confirm whether coolant is entering the combustion chambers but not necessarily exactly from where it is coming through. The test would take around 3 minutes and cost about £10.

If the test does not show combustion gas present then there is no problem there and coolant is leaking externally from the engine (and hoses) or transmission fluid cooler (automatic only) or even the heater matrix. Another option for loss of coolant is defective pressure cap on the expansion tank...cheap to replace.

Another option to slow down leaks through porous heads is to put some coolant 'stop leak' (the liquid version) into the coolant and this blocks minute holes. This option can sometimes last the life of the engine.

Let us know how you get on with it all.

Cheers  Trevor

[leo1976]

Thank you Trevor.  Appreciate the welcome and response.  Still find it hard to believe after six months of owning the car this has happened.  Feel like I should not have sold my BMW E46 convertible.  132K miles on the clock and no issues.  Thought by buying a 3.0 litre engine it would last ten years!  

Do you know if Audi UK would do anything about this?  Is it worth calling them and asking the question.  Any view points on that.

Many thanks in advance.

Leo

[Trevor]

It's certainly worth asking the question I suppose...see where it gets you

[leo1976]

Hi Trevor

Appreciate the reply.  The £5250 I mentioned now appears just to be the labour.  Audi want £7803 including VAT.  However as a gesture of good will they will fix for £4694.77.  The saga continues....... 

[Trevor]

oh my goodness...that's still a huge amount of money.

I would certainly contemplate putting some coolant stop leak in the system first to see if that cures it because porous castings are only where there was an air pocket when casting the component and a simple stopleak solution 'cures' the minute hole and may last the life of the engine.