jhawkaudi

I have an 01 A4 1.8T. The thermostat gauge sits at cold, intermittently, and I get heat out of the vents. I was thinking that it could be a sending unit or gauge. I would like to test the senors/sending units but dont know were they are at. Can anyone help me...Thanks.

Hope to be on here more

hellbringer

Coolant temp sensor. .there's a nice write-up in the tech section. Also if you replace it, which is very easy to do. ..make sure you get another sensor clip (passing the knowledge someone shared with me). Mine fell into never never land and I'm glad i had another one! Dealer in CT wanted $350 + 6% sales tax for a $20 part.

In another thread, I shared pictures since mine was the originial from a 98 A4 2.8. .now the temp sensor seems very accurate and moves right on up!

jhawkaudi

were is it at in on the tech side. I looked for it and could not find it.

darthlordrenn

https://www.audiworld.com/tech/eng.html

AutohausAZ has a good price on a new one.

http://www.autohausaz.com/search/pro...ender%20Switch

AudiMick

There are two sensors inside the coolant temp sensor, one for the gauge and one for the ECU. You can use VAG.com to check the sensors however it's a cheap repair so it's worth swapping the unit out to see if it fixes the problem.

Some people mentioned getting a replacement clip, make sure you remove the old o-ring and replace it also.

It could also be your thermostat, you will still get warm air if it's stuck open. The heater should be HOT at normal temp, OEM thermostats tend to fail open, aftermarket fail closed.

If if it is the thermostat don't leave it too long as it will cause the car to run rich.

Reggie

Here are the tech write ups for him on replacing the two sensors https://www.audiworld.com/tech/eng66.shtml

https://www.audiworld.com/tech/eng54.shtml