hi, i really hope i can get some help here, ive got a 96 A4 2.8, i love my car!
when i stand and idle for a bit she gets hot and boils some water out, this only happens when im not moving, i can drive her at any speed and she is fine. could this be a water pump issue?
also i got leak on the drivers side of the car that causes a flood , but i cant seem to find it, any ideas.

 

You've got a leak that causes a flood? Your cooling system is a pressurized system with a substantial leak there is virtually no pressure in your system meaning coolant is not flowing over the hot parts of the engine it is supposed to be soaking heat from. This is a problem. The reason its boiling over is I suspect a bad water pump. Could be a stuck thermostat but my money is on water pump, with no coolant circulating because the pump isn't working. The coolant that sits there and boils like water on a stove is the stuff that is touching the really hot parts of your engine which unfortunately is not flowing through your radiator to be cooled by air flowing over it from driving or cooling fans. Once again to the flood of water you referred to; does it **** all over the ground or do you just find yourself filling it alot? You say its fine at any speed don't kid yourself anymore man. You have a critical failure of your cooling system. You may not notice it at speed because you dump all your coolant on the ground through your leak. You could have a stuck thermostat with a bad water pump which doesn't allow your coolant temp sensor to measure the actual temp of the block not the temp sensor in your resevoir which probably has very little going into it while driving being its draining on the pavement as you go.

 

Hey krystallblue, thank for the info, i will have the water pump and thermostat checked out.The water does boil out the filler cap of the radiator bottlei think as i know there is a presure relaes at the bottem of the bottle as well,
But i only have to fill with water when she over heats, other wise the water stays at a constant level.Do u think thers a chance of a blown head gasket?
She only gets hot when im stuck in traffic

The leak that causes a flood in my car is a leak from the outside into my car when it rains and that causes a flood on the right hand side if the car

 

Have you checked the resevoir cap? If you are not truly overheating, according to the temp guage and your general opinion on how the car seems to be performing. It is possible that a resevoir cap itself fails, as a consequence what would not ordinarily boil out of the system does because of the lack of ability to maintain pressure thus escaping through the resevoir cap. A buddies car (03 b6) also had similar condition to what you are describing it was the seal that the cap made with the bottle. It looked as though someone had at one point driven it so hot that it did boil over and the coolant was hot enough to warp the plastic ( I have never heard of coolant being hot enough to do that though, wonder how hard you have to be beating the **** out of it to do that?) of the resevoir that seals around the cap. Replaced resevoir and cap and it was fine after that. Just a thought.

 

In your post you say "But i only have to fill with water when she over heats, other wise the water stays at a constant level." You are not refilling your car with just water?! I hope you meant to say the proper coolant. Long list of reasons why water is not an acceptable replacement for the coolant you have lost top 2 that come to my mind:
1) Coolant acts as a lubricant for your water pump. Water has nowhere near the lubrication properties required to protect your water pump from failing. (if youv'e been filling with water for awhile and now your problems seem to be worse its a safe bet that both your waterpump and T-Stat are ****.)
2) Water has nowhere near the boiling point of coolant. Water gets to boiling temperature long before the proper coolant does. So if your really really lucky the only problem you may have is that you are boiling water, the cooling system is doing what it should and releasing the pressure.
So if your using water replace it with the proper coolant and see if that doesn't solve your problems.

 

I did notice that there is a a rubber seal missing in the filler cap, but didnt think that could be a problem, will look into that.

I do use water coolent to top up the liquids that run out, i know how inportant this is to keeping the car cool.

Found another user on the site with similar problems and his was the water pump and the thermostat.