Earlier this year I had a catastrophic EGR valve failure, resulting in a new cylinder head gasket, closely followed by an oil cooler failure.
Since then, I've been monitoring coolant levels and have been alarmed recently at the rate of loss.
So, I had the system pressure tested at the local VAG garage and (thankfully) they've ruled out the gearbox oil cooler, but they are suggesting that the EGR cooler may be faulty.
They've also checked the heater matrix and found no leaks there.
So, they're quoting me 2 hours labour (£196 inc VAT) just to diagnose the fault, which (if necessary) will be followed up by either a replacement EGR cooler (at £300 inc VAT for the part alone) or back at square one, but £196 lighter in the wallet.
Can anyone here suggest any other reason why the coolant is leaking if:
a) The pressure test yielded no external leaks
b) A glycol test in the gearbox has found no coolant in the gearbox
c) The oil cooler, cylinder head gasket (bolts, etc) and EGR valve were all replaced in June (and therefore warrantied)
d) No coolant leaking behind the dash/ into the footwell from the heater matrix.
Is there anywhere else the coolant could be going?
Please help as I need to work out how much this might cost to fix, and whether or not there is some other cause that hasn't been considered yet (that might be cheaper)...
Also, if the EGR cooler is leaking, would that bring water into the engine oil, or would I simply see more oil coming through into the coolant tank?
Thanks in advance!!!