Motomaniac77

I pulled into the park with my kids, the car sat for about 15 minutes, then I hearrd a bubbling noise and noticed coolant coming out from under my car. It wasnt a flood, but a concerning amount none the less. I had just looked at the guage a few minutes before stopping and it was dead center as usual between cold and hot. Engine temp was spot on as well. Without other option and no where near an auto zone or store like it I topped it off with some water and headed home, at frist stopping every mile or so, popping the hood and looking. I saw no change and the temp guage still never moved so I went ahead and got it home. All readings are ok, and I drove 20 miles and there is no leak...there is just as much water/coolant mix in there as when I left. I just started researching so bear with me but is there some coolant overflow valve or something such as that which would give me that kind of occurance? When I was looking under the hood I did see what appeared to be some light fluid bubbling just below a connector in a fitting behind the head. (coolant temp sensor? I dont know where it is on this car, I havent had it long) Anyway...any ideas or theories I can try wold be greatly appreciated. I will continue to research through the evening. Thanks

turbo510

If the gauge shows normal but the coolant overflowed, maybe the cap is defective. These can be bought for less than $5 (autohausas.com for instance). You may also have a bad coolant hose, which will leak after you stop and the pressure builds. Try to diagnose because you don't want a hose to let go while you are on the road. I had a heater hose go out on my 2.8, first indication was steam from under the hood after stopping for gas.

computrtutr

The 'fitting' behind the head you describe sounds like the coolant flange. It's not easy but your best bet might be to get a mirror and flashlight and inspect it- that is a very common point of failure in these cars. Not hard to replace if it is the problem, just a real pain reaching bolts due to the space available.

Motomaniac77

after further investigation I do believe it is that flange...but I have anopther issue now too that I havent diagnosed yet. on my way home just a few minutes ago it started running reeeally rough. this time when I got home half the coolant in the reserve tank was gone, and my oil is low. I do have a small drip from behind the head...but this is all wthin 30 miles....starting to wonder if this purchase was a mistake already :/ I know these things are a bit more maintenance than others but geez I was hopeing it would hold together a little better in the short amount of time I have had it.

Motomaniac77

I should add I checked the oil and coolant right before I left and both were right within the marks they needed to be...

computrtutr

I had my doubts when I got my first 5000S too... but once you work through the initial couple of issues, you'll know what noises to look for and what is just the sign of an aging car. It's really rewarding once you get used to the idiosyncrasies of the car- Trust me, I drive a 2000. I guess the first place to start is the basic and obvious: Have you made any changes or mods to the car since you got it? Any repairs? if so I'd start by looking around areas that have been touched recently. Any codes? Is there any coolant on your dipstick? Of course, there is no substitute for jacking it up and poking around with a flashlight. You might want to check the timing belt path and make sure that and your water pump are good (It is a bit of a job, but if you just remove the front apron it's all right in front of you). Let us know what you find. Good luck!

turbo510

The low coolant might be the leak, but the bigger worry is the oil; You actually lost a bunch in 30 miles? That would have to leave a trail of drips or smoke. I hope that you get it all sorted out, because these A4s are actually pretty reliable and somewhat simple, especially compared to the 5000 series that computrtutr mentioned (I've had three of those things). My A4 has well over 200k, common on this forum. My last 5000, a CSTurbo, was a basket case at this mileage. The A4 seems like it's just broken-in.

mtroxel

...or a lot of oil in the coolant. I know that motor doesn't have a history of head gasket problems, but oil and coolant disappearing can be a symptom of a head gasket, or cracked head.

You need to confirm you're using that much coolant, and particularly that much oil, in a 30 mile trip. If you are, and don't know where it's going, you need to think about some serious issues with that motor.

Motomaniac77

I am about to head to the garage to do some serious investigation. The reason I bought this car is it was a one owner car, (I purchased it only 3 months ago with 149k miles and it simply purred like a kitten) it had ALL dealer and audi certified shop work done to it. These people literally did nothing on the car themselves I think. I have a fat stack of recods with the car from 3 different shops including the dealer to prove it. I have NOT ran this car hard. I have only had 2 instances of what I would call brisk acceleration since I have owned it just to get a feel for the car. Constantly checking oil and coolant levels to keep up with whats going on with it, i Love this thing. Considering the way its acting now i'm just a bit frustrated, I cant really afford a major repair right now. There is a small oil leak at the seam of the valve cover on the back of the head which causes a slow drip...thats the only indicator of the oil leak, and the flange discussed earlier the only coolant loss, that i have found yet. I will jump on later tonight and let you guys know of any other findings. I was up all night working so I'm just getting started. Oh the car is completely stock as well. no mods whatsoever

Motomaniac77

The oil level is ok. Its right in the middle of the mark where it whould be. I probably just hurried to check it after I got home due to the motor issue and the oil hadnt fully stlled yet. The oil is not creamy or runny. However the coolant I wnet from the nearly full mark when I left, ot nearly the -min- mark when I got home. The car seems to idle normally, but as you begin to put rpms into it it feels like a hard miss or something. I'm going to pull the plugs next.