Problems with A3 losing coolant

[Tina89]

Hi all, just wondering if anybody could help, or shed some light on my situation. I have an A3, 2.0 diesel, 2010, had it nearly 3 years and it’s just hit 70k miles. Since end of last yearish, I noticed that it was losing coolant. Had many different friends who are good with cars and mechanics look it. No signs of head gasket gone at all, other than the losing coolant. Engine has never over heated, temp is always fine. A mechanic diagnosed a possible leak from the EGR cooler, and it went in to Audi about 4/5 weeks ago, and was found to have a leaking EGR secondary to the recent emissions upgrade and was repaired for free. However, I drove to Suffolk from Stoke-on-Trent at the weekend and the coolant is again empty! When I pulled up at services i felt as though I could smell the coolant, like from the warm engine if that makes sense. I’m really at a loss as to what the problem is and what to do! I don’t know a lot about cars, and don’t want a mechanic ripping me off saying it’s this and that. I just feel like no one knows what the problem is. Any help or advice greatly appreciated thank you!

[DuraAce]

Find some better mechanics to look at it?!

If you are losing coolant then it must be leaking either externally (radiator, pipework, water pump, heater matrix etc) or internally (into the engine cylinders)

Cooling system pressure test and cylinder leak down test would point you in the right direction if you can't visually find the leak.

[Tina89]

That’s fine saying find a better mechanic, im a young female, and I have been ripped off before when I had a Leon, so don’t want the same again. I will ask around for reliable mechanics. I had checked the coolant and replaced the lid myself so know it was correctly fitted. I’m happy to pay what it takes, but I don’t want to be replacing things like the water pump etc to find out that isn’t the problem. Hence I nearly paid a mechanic to do the EGR, and that hasn’t solved it. Thankfully Audi repaired that for free so haven’t lost out. Sadly my dad and brothers aren’t into cars

[Belle427]

Water pump leaks are very common but hard to spot as it’s not that visible in the engine bay.
It’s one of the first things I’d check.

[catso]

My old A3 had a slow coolant leak for some time, it wasn't easy to see where from but it was minimal so I put up with it for a while.

Then (unrelated) the fan controller failed, leaving the cooling fan permanently on to flatten the battery and so the fans needed to be replaced. Once stripped down it was discovered that there was a small leak on the radiator that was all but impossible to see without stripping down to that stage.

Don't know if it's a common fault?

[gizlaroc]

I would have someone check the water pump, they do fail and leak.

I would fill it up and bleed it properly and then listen to the engine it should sound 'right'.
Then after a drive, the next morning lift the bonnet and start the engine, does it sound really rough?

Water pumps that are leaking can sound like your engine has gone, the blades sinning round are quite when in water, any air in there and it sounds really bad.

[Anthony147]

I had a similar issue, brought my A3 in August, about a month of trouble free driving and suddenly coolant light came on. Topped up my coolant, 4 days later light on again and empty reservoir (not just below the line but empty) this repeated every 4 days. Took to garage who ran a pressure test, checked what they called “usual places”, nothing. Took to another garage and again nothing. After that in a separate issue my coil warning light came on, so took to Audi. Did the fixed price servicing £60 for diagnostics (turned out was £60 for 1 hour diagnostics, after a lot of arguing and showing the website that it at no point stated 1hour they agreed to do a full diagnostic)
They came back that I had a coolant leak from the EGR coolant reservoir that had knackered my EGR valve (apologies I have very little experience with cars so terms may be wrong)and that was what was causing the coil light, anyway got that sorted and no more warning light, and a bonus coolant still hanging around 2 months later.

[Tanker123]

Nice to here about happy endings with water leaks on A3 Audi, I have a problem with my Audi A3 63 reg with only 58k on the clock ive had it 4 years, and its been a great car, but over the last 4 weeks have noticed a shortage of water in the reservoir, and haven't got a clue where its going, just before i went to Ireland in sept, to be on the safe side i had the cambelt replaced and water pump as millage on car was around 56k, all work was done by Audi specialist, after i came back i put the car in for a full service Audi specialist again, at the same time i asked them to look at my heater as it was blowing cold air, they serviced the car , and then told me that the top up bowl reservoir, has an ine'r liner and over a period of time the inner liner disintegrates and flows into the heater system known as the matrix thus blocking it, and if i wanted a quote it would be 1,0062 pounds, i then contacted a fitter i know and he done a matrix flush for 120 pounds , plus i bought a new reservoir altogether 148 pounds, still hasn't solved the problem of the water leak but heater is better but would say about 70 percent as it should be, car is booked in next week to find where the water is going and another matrix flush i just hope it isn't anything more serious, any thoughts would greatly be appreciated. Ray

[Bhatts999]

Hi,
Just wondering did you find the solution, as I am having the exact same problem?

Thanks,Ali

[EX21]

Totally fed up with trying to find where my leaky coolant is going, the fan, reservoir and EGR have all been ruled out by my mechanic. A3 Sportback 2014. It actually coincided with Audi fiddling with the air conditioning they said had a leak but that might have been coincidence. Head Gaskett is next in the list but mechanic is unsure whether this is the culprit…answers on a postcard. This has turned into a complete mystery.