my car has been giving issues where it wont start at times, the engine turns over and everything but it wont start. sometimes it starts after 3 tries sometimes more or less. sometimes it starts right away. i had the battery, alternator and plugs tested and everything is fine. it mainly gives this issue on days where its hot outside and the car is parked in the sun. or when i have to use the AC. there are no lights on the dash. at one point we thought it might be a battery drain but my mechanic checked everything but couldnt find a drain. it is 01 audi A4 1.8t. any idea would be welcomed so when i go to my mechanic i wont have to spend too much money on him just diagnosing it. at least i will have a starting point. based on what i have read in other threads im leaning towards it been it being a Engine Coolant temperature sensor. What do you think?

 

I share almost similar symptoms on my 2.8. It does start, but when its hot and humid, my car runs rough, misfires, especially when I turn my AC on.

It could be the ECT because I've had my coolant temp gauge go up and down erratically.

 

I took it in to the mechanic and while the car was there, it had the same problem and wouldnt start and he couldnt figure out what the problem was. so i told him what i found on the forums that it might be the ECT , so he is gonna change it then go from there.... hopefully thats the problem and nothing else, because this car is driving me crazy and broke.. i cant keep up with the repairs on his car. every week is a new problem...