x05179x

Hi,

I am hoping some can give me a few suggestions on the issue I keep having with my 2008 A4 2.0T. The car has roughly 60,000 miles on it. About 5,000 miles ago, the check engine light came on and I scanned the OBD port with a scanner. The code that came up was P2181 Coolant System Performance. A lot of folks suggested replacing the coolant temp sensor. Audi seemed to think that the car has Two Sensors - a gray and green. I believe I replaced the green one. It was on the passengers side of the motor near the firewall. I didn't get a code again for another few thousand miles. Now the check engine light comes back on, same code (P2181) and I cannot figure this out. The temp gauge read about 1/4. Which seems on the low side. It rarely gets slightly above quarter. However, the car blows hot air inside the car.

So, if the gauge never gets to 1/2 and the car blows hot air could it be the thermostat? Is there really two temp sensors? Does someone know where the other one is located.

Any help is appreciated.

Scott

x05179x

I forgot to also mention that I have a bluetooth OBD sender that connects to my ipad. The readout on the coolant system is between 156 degrees to 162 degrees. that seems low.

ziobello

I have the same 2008 A4 2.0T with the same exact problem. I'm getting code P2181. Is the coolant temp sensor something easy to replace?

Did the problem go away afterwards?

Thank you!

Dolamite

Change your thermostat if you are having identical problems.

ziobello

Are you referring to the "coolant temperature sensor"?

ColoCoug

I'm not familiar with the logic of that system, but I'm wondering if you could get an alert from temp too LOW...which is exactly what's happening. The engine won't reach full operating efficiency unless it's running hot enough. Sounds like you have a thermostat stuck open.

ColoCoug

^^Zombie thread. I would delete that post but there's no EDIT button available.

Kris Hansen

Yeah, thermostat. You'll get decent enough heat with a wonky t-stat, but that will also pull all of the heat from the engine. it's bad for the engine to run always cold like that.

emanuel1331

Hello,
I am new to this so im not even sure if im doing this correctly lol, anyways I have a 2004Audi A4 1.8T and a couple days ago I noticed that the enigine fans where blowing very loud and hard and and then just today the check engine light came on and it was P2181, I know that this could be either the Thermostat or the sensor but why would the fans be blowing like this? Ireally hope i get a response Thanks !!

Dolamite

What is your coolant temp gauge showing? P2181 most often than not is your thermostat. Ideally you'd want to change both around the same time as regardless. The fans blowing could be associated with a malfunctioning sensor. What is your heater doing?