Hi guys! So I have a 2004 A4 1.8t fwd auto and had about 95,000 miles! Recently the temp gauge was overheating but no leaks!! So I replace the raditor and timing belt and new water pump!, so after all of that now the temp gauge goes down to cold and stays there then bounces up to mid point the. Back to cold!! So what else cab be the problem that is causing this? Mech said thermostat but I don't think it's that bc it would be overheating! I'm I correct? Please let me know thank you

 

The car still has full power n fans and everything works fine! I didn't check sensors and I did order a new coolant temp sensor! Now can I still drive the car or should I wait til I fix the sensor? I don't want to ruin my engine!,thank you for the reply

 

Coolant temp sensor should fix it - it's a common failure.

 

on my 2000 tt it would run cold all the time..even after driving for an hr..i might go from the coldest notch up a mark or 2... but would never go half way...that was all stock.
on my 2001 tt the temp gauge runs a little itty bit past 1/2 way..goes from a cold start to 1/2 within 5 mins of driving. the engine stays hot for hours after driving..even if it is for only 10 mins. i replaced thermostat, gasket for thermostat, ECT sensor, coolant flange, water pump. i think my old thermostat was stuck causing it to have coolant run through freely constantly without having any pressure applied to open the thermostat. i must say that i liked having the colder engine bc performance always seemed better and stronger. if you figure anything out..let me know

 

ive replaced the ECT before. different color. went from stock green to blue

 

Shouldn't have done that. The green one is appropriate for your car. Blue is older and meant for earlier cars.

 

all right well i still have it so i will switch it out today and hopefully it changes that!! if not; no harm done. thanks man

 

also, how do i start a new post/thread for other problems..? i cant find the button anywhere or under any of the tabs

 

Definately sounds like the Temperature Sensor mate. I had the exact same problem on my B5 TDI only a few weeks ago and after changing the sensor all is now well.

It isn't even that difficult of a job as if I can do it anyone can. How is the oil temperature reading? Is it reading ok? Sometimes it can give incorrect readings when the Temp Sensor goes.

Sounds like the sensor has developed a fault due to the overheating.

 

i changed it within 3 months ago. but i will definitely try it again! thank you for the suggestion. i do not have an oil pressure or temp guage..just electronic display that will show an icon if the oil level is low. i need to buy some and install them...