Hey everyone. Got a problem with my 99.5 A4 1.8 (90k miles; yes, the TB recently changed). Temp gauge is registering low (on the first line above stone cold, perhaps a little higher). I pulled the ECT and cleaned the gunk off it; reinstalled it, but no change. I'm going to get a new ECT first, but in case it's the t-stat.... where the heck is the t-stat located on this engine? Please tell me I can get to it without dismantling a bunch of stuff!!

FWIW, the car is running fine, and my mileage seems fine (29.9 hi-way on 350 mile trip last week, 23 here in town). I just want to make sure it stays that way!

Thanks in advance.

Steve

 

Change the thermostat, it is probably the problem, and they can cause other problems when they go bad. It's only like $10 at napa. (there are 2 different types though, blue and green, just get the right one so the connector will fit)

 

Thanks Bishop. I'm still a little confused, though. Isn't the thing you circled in the photo the coolan temperature sensor? Or is the t-stat housed in the tube where the sensor is seated?

I ask because I've read a number of posts that say to replace the t-stat when the TB is changed, which is nowhere near the rear of the engine where the temp sensor is.

Thanks!

Steve

 

the thermostat doesnt have an electrical connector. that is the coolant temp sensor. the thermostat is located underneath the car on the bottom of the water pump. if you jack up the car, look towards the drivers side and you will see a little bulge on the aft bottom part of the water pump and that is your thermostat housing.