Just curious as to where the thermostat is located on an 03 A4 1.8t. Just got the car and going through all the basic mechanics and replacing them. Anyone know where I can find a replacement for a decent price and a how-to on replacing this?? Thanks in advance!

 

ahh the trusty old thermostat.. dont replace it unless you need to. They run about $150-200 list price (dont quite remember because I get stuff at cost) Its an electric thermostat so that is why its more expensive. Its the entire housing unit that you end up replacing.

Location: On the 1.8T engines it is located on the drivers side of the engine below the intake manifold, towards the front of the block, and pretty much made invisible by the alternator.

To replace you will need to put the front clip into the service position, remove the alternator, and the Throttle body (This will require you to do a Throttle Body Adjustment when your finished). And then a couple of hoses that are connected to it that can somewhat be a pain.. but if your patient they wont end up being that bad. If you want more details on what or where its located I can help ya out.. just let me know

 

In this picture where you see the red G12 coolant. That is where the thermostat sits. If you see where the timing belt sticks out to the right directly on front of that... that is your Water pump. Stock the pumps came with plastic impellers that are known for going out. When/if you replace this make sure you order the one that comes with the metal impellers

 

Alright thanks for the info Karl. I'll look into replacing that too while I would have it apart. Yeah the thermostat is causing me issues tho...it's stuck open sometimes so im just replacing it so that one of these times it don't stick closed. That would suck majorly.

 

I wouldnt replace the water pump unless you need to.. because it requires you to remove the timing belt and "sometimes" it can be a pain to get it lined back up if you havent done it before

 

Im also bein told that it could be the coolant temp sensor?? Which makes sense since its electronic. What do you know about this type of issue? Thanks in advance!

 

well the problem I ran into was that my coolant temps would be fine at idle.. once i started driving they would get extremely high.. this was caused by the plastic impellers on the water pump so once you pull of the temp sensor, you can stick your fingers in and feel where the impellers are on the pump.. see if there is some play there

 

Well replaced the coolant temp. sensor which thank god I have small hands cuz it is a bitch to get to but I did it! Seems to be starting fine now! Got the new sensor for 27 bucks and saved money on the labor by doin it myself.

 

Lucky you, I pulled my thermostat and found my water pump impeller spinning freely. Luckily I was tearing into the car to replace the TB/WP and thermostat. Glad to hear you got it fixed though, and for only $27 bucks. Nice.