I have a 1998 A4 2.8, I was driving and all of a sudden my engine starts to over heat. it looks like there's no aparent reason, I checked and it's not low on oil or coolant, there's no leak either. I can't check for trouble codes right now 'cause I'm typing this from my car on the side of the road waiting for it to cool down then I'm heading to the nearest gas station. What could be the problem? And how could I fix and prevent this from happening again?

 

It could be your thermostat is stuck closed or a sensor... If it's the thermostat you might as well do a timing belt and waterpump while your at it

 

idk if it would be the thermostat, assuming its similar to the 1.8 design, its a fail safe design, meant to stick open when it "breaks down" as opposed to sticking shut.

though doesn't mean a"design" wont fail.

in my 1.8 my thermostat was broken when i bought it at 92k and changed at 100k, it warmed up(took a while) the gauge never went higher then 1/8 but my gas mileage suffered. though never overheated.(did the opposite actually)

 

thanks for your help guys, i hope you're still subscribed to the thread, i have done as you recommended and a little more, i've changed the thermostat, water pump, timing belt, drive belt, fan clutch and coolant, and i've flushed the system, but it's still over heating. what else could it be?

 

stick a mercury thermometer in the coolant and see if its actually overheating. Might be a temp sensor.

 

ok this is where the temp is now, as i've said before, we've changed thermostat, waterpump, we flushed the radiator and flushed the heater core. it's not overheating anymore but that's where the temp gauge is staying at right now. anything else i can do for it to go down more?

 

It should be at 12 o clock.

Did you replace the coolant temp sensor?

 

Does turning the heat on full blast help pull the temp down?

 

no i did not. i think i know the answer but i'll ask anyways, does it get damaged when the car overheats?

 

no, if i turn the heater on it'll lower it just barely noticably below the line it's above.