2002 A4 1.8T Coolant Level Low

Hello everyone. It's me again, with yet another problem with my least favorite car of all time!
My coolant level light went on the dash this morning. I had driven
the engine hot, so I brought it home and checked the level. When hot, the level was two or three inches below the "min" line.
So I got out some engine coolant (the red stuff) mixed it 1:1 with water, and added it in. However, when I opened up the engine coolant compartment, the liquid must have still been pretty warm, so it kind of boiled and bubbled a bit. As the air seeped in and the screw top came off, the level rose back up to the exact right level.
Not sure what to do at this point, so I waited for the car to cool completely. Once I did, the level dropped back down again, but not all the way to where it was when I first checked it. Maybe just an inch or two below the "min" line.
At this point, I added in my coolant mix up to the proper fill line and re-capped the tank. I haven't driven it since.
There are no leaks coming through to the ground, although it does seem like there is a bit of liquid collecting underneath the passenger side of the radiator compartment -- not in front of the radiator, but on the engine side of the radiator.
So what's the prognosis? I know I should take it in, but I have to get to the airport tomorrow morning. I'm hoping the top off holds for a bit and will be fine in long-term parking for 6 days.
By the way, this is a 2002 A4 1.8T with about 44,000 miles on it. It has been in the shop (in just the last six months) for the following:
New thermostat, two vacuum hoses, air-conditioner that wouldn't blow cold air, and all the regular maintenance. And, of course, the car has also developed the clunking noise under the driver side wheel that I am talking about in another thread. This should not be happening to a car that is under 50,000 miles.
Anyone in the market for a used car?
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If there's a slow leak, it will be less pronounced when the car is not running. Just check when you return to make sure there's not a large pink puddle under your car. There are severalpossibilities for the source: cracked coolant recovery tank ( the thing you opened up to add coolant), leaking radiator (I had to replace mine at 65K miles for about $700), leaking hose, leaking heater core (but then you'd likely smell coolant in the passenger cabin), leaking temperature sender, cracked engine block (but then you'd be seeing some whitish smoke out the tailpipe.)

one who agrees with you on the reliability of that vintage of A4 (I have a 98.) Somone earlier lauded the sophisticated Audi engineering but as an engineer myself who has worked in the automotive industry, I can assure you that "sophisticated engineering" requires attention to longevity of components and the overall system and that's something that VW/Audi has taken a long time to learn if it yet has. Hyundais OTOH were pretty crappy when they first arrived on our shores but the improvement in those cars has been nothing short of amazing.
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iws knastet inn: :

With good [high] pressure in the coolant system, it's not too much to worry about. You got it with the new thermostat ... higher temp, higher pressure.
Sounds more like a small leak around the water pump axle, may happen when it's time to change the pump. I drove mine for several months since it started leaking... Until it was time to change timing belt, then - I replaced both timing belt and water pump.
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Could it be that coolant pipe on the rear of the cylinder head? Look at the oil cooler sometimes those hoses leak. That is IF you have a leak. Usually you will see some red cruddy looking coolant residue at the leak.
Maybe the thermostat has the leak. Why was that changed?
--
later,
dave
(One out of many daves)
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the thermostat was changed out because of a faulty switch, or some sort of electrical part. i don't think it was related to the plumbing of that part.
so who wants to put odds on what will go wrong next on my audi of doom? my money is on the control arms! i'll take bets at 50-1 that the cd player starts shooting discs at me when i put the car in reverse.
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i appreciate your thoughts. i'm just embarrassed more than anything for owning this car. i'd trade it in today, but it has dropped in resale so quickly that i'd lose about $5,000. but $5,000 is about what my repair bill has been over the last year of ownership, and who knows if it will be $5,000 again for the next year, or maybe more...
my mechanics know me by name. that shouldn't happen on a car with 44k on it. ti know they're laughing behind my back every time i bring the car in. 'what a dupe. who buys a clunker like this...'
anyway, thanks for the moral support. i know the car has gotten under my skin, so i vent here. and maybe i fixate too much, but the other night i did have a nightmare in which my dashboard lit up like a christmas tree with dozens of bleeps, dings, lights, and flashing warnings. you know your car is screwed up when you wake up in a cold sweat worried about your "check engine light".
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I had the same experience as you and Frank.
I have a 2002 1.8 A4 with about 95K and noticed a coolant leak problem a few months ago. As it turns out, the leak was just a gasket but after a little research I found out that it's a good idea to have the timing belt and water pump replaced around 90K so ended up paying around $1200 to get everything fixed.
If you think your mechanic is laughing behind your back, you might need a new mechanic!
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Paul Johnson knastet inn: :

Audi & BMW mechanics are often seen laughing, all day long ;-)
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