Morning all, whilst on holiday 300 miles from home and everything I own, I've had a lovely steam filled 2 mile journey back to our temp accommodation. Due to travel home on Saturday morning and no garages around can fit the car in. I suspect the EGR cooler is damaged internally. Symptoms being severe coolant loss (full exp tank disappeared in a literal few miles), lots of steam and water from exhaust when engine is warm, no residue in oil and no oil in coolant. No sniff test done or possible. The car has had a small coolant leak for a while which was suspected to be related to a blocked heater matrix but it seems it's now had enough, I had noticed a bit of steam previously but mornings had been colder and thought nothing of it. If I was at home I'd start taking it apart, but being miles from home, space and tools I can't do that here. Once it's home it can be repaired but I could do with a solution to get her back...and I'd rather not start taking bits off and realise it's not possible...

 

The car is a 2014 2.0 TDi CKFC, completely standard.

It goes without saying....don't drive the car with no coolant!

 

If the steam is coming into the cabin, then the breach will probably be the heat exchanger in the cabin.  Check the silica bag of doom has been removed (in the header tank), but it could well be the system has either over pressured or you do indeed have a failed heat exchange.  First things first - put water into the system (i.e. top it up) and then pressurise the system (using a pressure test kit) and start checking where the leaks are.  Also check the carpets...if they are wet, then its definitely a heat-exchanger issue.

 

You will need to flush out the system post repair and then refill with G12evo.

Pressure test had been done with no sign of a leak. The matrix is blocked, has been for a while, but not due to the silica bag. This is fully intact in both the original expansion tank and the replacement I put on. The residual casting sand and rust is the culprit for that! 

 

Strangely though I filled it up, took a load of water with us and it drove the 300miles home fine...no steam , also checked it a few times on the way back and levels hardly dropped at all. Took it out this morning and still no real loss...bit baffled by it really!

 

The leak for this post definitely wouldn't have been the matrix, that would have been very noticeable in the cabin with the amount of coolant lost, but there's no wet carpet or anything and never has been.