P2181 Code - Engine Cooling System Perform - HELP!

[protoaudi]

So i have done alot of research on this code and havent found much on our car with this code. I found one posting on a forum of someone saying it was triggered by an aux. radiator hose. The code is P2181 - Engine Cooling System Perform. I already replaced the CTS. The Coolant Temp reads at a little over 1/4 when it should be at operating temperature. The upper radiator hose seems to be very hot, so i doubt it is the thermostat. But the bottom radiator hose going from the junction back to the block dosnt feel nearly as hot. Fluid is full. Anybody have an insight on this.

I have a matco scan tool that i clear the code with mostly every week. Once i clear the code it will trigger sparaticly. Sometimes 1 day, sometimes over a week. Would love some answers. Thanks!

[protoaudi]

bump......someone must have some input (is there some kind of check valve in the bottom radiator hose?)

[STONER]

Probably the thermostat sticking. I would replace this and see what happens.

[protoaudi]

but the upper radiator hose always remains hot, so replacing the thermostat would not make any sense.

[PAT@RSW]

For P2181 Check the Following:

Engine Coolant Temperature Sensor (G62 ), Check Coolant Pump V50, Check Coolant Thermostat Operation

[STONER]

You could be driving and it malfunctions for just long enough to throw a fault. It may not happend all the time. It may have only occured a few times.

[clemsongt]

I have the same issue. The CEL will come on for that problem and eventually it will turn back off..and stay off for a while. It has actually been quite a while since the last time it was on. I don't know what the issue is, but I have determined that I have a very small coolant leak. This might have caused the light. I think (based on where I've seen the buildup - bottom of oil pan and lower pulley housings) that my water pump is probably on its last leg. I'll eventually get around to replacing the water pump when I do my timing belt change, but the leak is so slight now that it isn't even an issue.

Don't know if that helped you at all. Definitely keep us posted if you figure anything out. Good luck!

[protoaudi]

where is the thermostat hosing? I cant seem to find it. Is it between the back of the engine and the firewall?

[clemsongt]

where is the thermostat hosing? I cant seem to find it. Is it between the back of the engine and the firewall?

http://www.audizine.com/forum/showth...ng-Belt-Change

See "Part 2"

[yellowsnowx]

anyone figure anything out?
mine just threw this code, stayed on about 2 weeks, then i cleared it.

just had a friend with a b6 have his coolant reservoir blow up on him while he was driving back to college a few weeks ago... he wasnt paying attention and doesnt know anything about cars and ended up overheating everything and now his whole drivetrain is toast along with most of the car

[schmiesus]

T-stat

[bman005]

T-stat

this

[Andrew@RAI]

yes replace the thermostat its a pretty common issue with these

[-Boosted-]

Definately the thermostat. The fact that the upper radiator hose remains hot does not rule out the t-stat but instead supports the diagnosis. The thermostat is sticking open which in turn will not allow the engine to get to optimal operating temperature.