View Full Version : 1999 A6 2.6 Coolant loss

09-07-2007, 02:43 PM

My A6 has has a very slow coolant loss problem since I bought it in 2004. It takes about 3 or 4 months for the coolant to drop from Max to Min. I know this is slow, but no other car I've had ever lost any coolant. I've had the car into my local garage 3 times in the last couple of years and they have pressurised the system and identified a leak each time - which they repaired (it has occured to me their pressure device may cause a leak).

However, the very slow leak remains. I'm reluctant to take in to another garage and pay 40 or 50 just to find the problem remains in a couple of months time.

Any suggestions?

Also, I had the water pump replaced recently, and they filled the car up with green coolant - not the pink stuff which it used to have in it. Is this a problem?



09-07-2007, 04:47 PM

You do not say if there is any external signs of a leak (eg from hoses or radiator) and also when the garage found a leak where it was and what they did to fix it.

If there is no external leak then it is either evaporation (unlikely) or an internal leak eg cylinder head gasket starting to go. The signs of a cylinder head gasket problem are quite easy to spot:
1. loss of coolant.
2. rough running on start up.
3. white "smoke" / steam from exhaust.
4. back pressure in the coolant reservoir (spurts out when you open the cap)

Do you have any of these or not? If not I would not worry too much but just keep an eye on things to make dure that they are not getting worse.


10-07-2007, 12:13 AM
Hi Peter,

The car runs great and cold starts always spot on. I do occasionally get low revs on a warm start for maybe a couple of seconds max, but not often. There's no sign of a leak, although sometimes I think I smell coolant but when I go sniffing can't seem to find anything. Sometimes I stall it when letting out the clutch with low revs - but have always assumed it's me trying to be too light on the gas. I'll check the white smoke in the morning, and also the back pressure.

I'll post the results tomorrow.

Does it matter that they put green additive in there?



10-07-2007, 10:00 AM
I don't think that the cvolour of the additive would make any difference. I presume it is a recommended barnd of coolant / antifreeze.

It does not sound like your head gasket (which is good) but I am not sure what it could be if you have no visible external leaks...



13-07-2007, 12:06 AM
I do lose some coolant by evaporation (I think ...it happens in the summer) but our temps are a bit higher in these parts. Top it of and keep an eye on the level and on the spots where you park.

15-07-2007, 10:20 AM
Thanks fellas. My mechanic pressurised the system to the maximum he dared and there was no leak whatsoever. He said he detected approx level 8 hydrocarbons in the coolant, but then it went back down again. He said it's possible to detect up to level 100 before a car is condemned. So I guess I may have early signs of head-gasket failure. I'll keep an eye on it.

I love Audis, but with 119000 miles this car is starting to need work. In the last 14 months it has needed:

new clutch and flywheel = 860
front road springs = 200
water pump (timing belt also due)=300

It also needs a new steering/susp fix this week as the front near-side is rattling and squeaking recently. Part is 17, labour approx 40.

Anyone know the labour time for replacing the head gaskets? Cost of parts?

At what point to you declare it's over and say goodbye? I could buy a new Renault Scenic and the fuel savings would virtually pay for it, and I'd have trouble free for 3 or 4 years - but then I wouldn't have an Audi anymore. Opinions anyone?