Audi A3 Coolant Loss

[redsweep]

I Have an A3 1.9 TDI, 2001 with 82,000 miles. I had a bit of an unfortunate run in with a sheep last July which resulted in a new radiator. Everything was fine for a few months then i started to lose coolant. I top it up and it's OK for a couple of weeks then the warning light comes back on. The past couple of days (while it's been hot) i've topped it up three times. Audi have had a look and can't find anything wrong (no fault codes and they also ran it for most of the day). All the hoses have been checked and still nothing. It happens from cold, i start the engine and after a minute the warning light comes on. I've taken to carrying water and coolant everywhere with me. Apart from the last couple of days (where it's happened more frequently) it's happened regardless of weather conditions, but not while driving. I've had another mechanic look at it but he can't find anything either. It's driving me mad, anyone else had a similar problem?

[Sam]

I presume you're using VAG spec pink coolant and can find no trace of crusty coolant deposits anywhere?

Common leaks are, back of the engine near the firewall and the oil cooler.

If you're mechanically minded, you could replace all the hoses to/from the oil cooler, I note you say they've been checked but it wouldn't hurt and has resolved many leaks in the past

[redsweep]

Took it to someone and they suggested the head gasket although I'm a bit sceptical as there are no other symptoms to suggest this. Tried to trace the hoses myself and got a sneaky feeling it's actually the coolant reservouir that's developed a leak somewhere, but going to get it pressure tested again just on the safe side

[redsweep]

Well it did turn out to be the coolant reservoir. It's been replaced and tested again and all is good.

[justinwood]

Hi there i have a 94 Audi Coupe and have just started experiencing coolant problems. For example I would top the coolant up in the morning, take the car for a run, and a majority of the coolant is then lost. However if I top up the coolant and leave the car standing over night the coolant level remains the same. I have checked for leaks and have found none, did this problem sound similar to yours when you first started experincing them?

Cheers for any help out there!

[redsweep]

Does sound quite similar. It actually turned out to be the head gasket, got to the point where it would just constantly lose coolant, but like yours only when being driven. In the end i found a very understanding mechanic who took the engine apart to try and find the fault, had the water pump replaced and thermostat and it seems that the age of the thermostat meant that it was disguising the problem. It did cost a bit but it is now in full working order. What was so annoying about this problem was that Audi would pressure test is and nothing would show up. Looking back one indicator to this problem was the amount of pressure that built up in the expansion tank. As I'd simply got used to it I didn't think there was anything wrong, but now there is very little pressure when you take the cap off. It cost about £800 to fix but that included new cam belt, water pump, thermostat, re-grouding and three glow plugs. I lost count of the times where people would tell me that head gaskets don't go in Audis, although it does seem to stem back to hitting the sheep!

[justinwood]

I to thought that the coolant tank was meant to have pressure behind it, which isn't the case, I'd just replaced the cap to the tank thinking the previous one had a leak however I am now of the belief that it is the head gasket :( . Not greatly impressed, especially when Audi gave me the estimated price with recommended replacable items including water pump and timing belt etc. It is going into the garage next week however to have the once over for £50, why am I of the belief that they won't find anything?