A4 3.0 Petrol - head gasket? Hydrocarbons found in water tank... :-(

[arvydasxx]

You just scared me as well, because I have same car as you have and it uses a bit of coolant and it steams a lot through exhaust, I have to put about 0,3 l of coolant for every 1000 miles, it also has quite a lot of pressure at expansion tank.

[mikeybutch]

Hope this doesn't discourage but I have no technical training being an ex banker and lawyer of sorts but I have been DIY motoring for a long time albeit slowly now.I have defo heard of oil contamination from other sources and would seek advice also get an allround check for coolant leak.Having looked at a few headgaskets( in my early days) I think the comp test will tell you if there is a leak assuming the piston rings are in good nick.If you are worried about coolant being burned off that might not be the same as a blow between the oil and coolant systems either in the h/gasket or somewhere else.Cant see why the work you had done would be relevant unless some oil got dropped in the coolant!!Perhaps this new comment might indicate that these symptoms are characteristic of some or at least not uncommon?After all a blown headgasket usually means poor performance and early demise if not sorted.Another crude test is to disconnect each cylinder in turn and see if any one makes a bigger difference than the others , arvydasxx don't think you should worry if the coolant loss is steady and doesn't worsen.Again you may have a small leak and the system is highly pressurised and no way should you remove the cap when hot.There is a lot of vapour on cold days before the engine is up to temp ;if it persists then I would be concerned

[arvydasxx]

Other than coolant loss and a bit of steam car runs nice and smooth, I have had a slight misfire on cylinder 5 for a week or two on high rpm but it disappeared and never been back..

[jullio]

Mayo now on the oil cap, oil sensor allert so things look to be going south.,.,. will see what the comp test brings....

[mikeybutch]

Sorry to hear what seems like unwelcome news but it could still be another source

[mikeybutch]

Regret that I cant find anyone to agree that its other than a gasket.I may have been thinking of a diesel.Its probably only one but that doesn't help much

[jullio]

Regret to agree.,.,. to quote my mechanic: Cannot be the water pump during the cambelt change , if you having hyrdocarbons in the water it has to be a head gasket for them to get into the water system, plus if the leak was external you would see it on the ground, and not form the exhaust...

[mikeybutch]

Not looking good.Thanks for sharing but I am beginning to wonder if its worth hanging on to mine and I keep bumping into someone with a 1.9tdi still going strong