P2181 - cooling system performance

[NODO-GT]

simple question, what should I check?

what i have found on web so far, most suggested is to check thermostat, but I think it's fine because car warms up normally and and reaches middle temps on the gauge.

I got this error when i was on highway, it was cold outside, 12 Celsius. I don't remeber but I think temp gauge was lower than middle, could it be caused just by low temperature outside and without any load on engine?

[CleverA4Name]

Temperature sensor?

[swaggerwagon]

simple question, what should I check?

what i have found on web so far, most suggested is to check thermostat, but I think it's fine because car warms up normally and and reaches middle temps on the gauge.

I got this error when i was on highway, it was cold outside, 12 Celsius. I don't remeber but I think temp gauge was lower than middle, could it be caused just by low temperature outside and without any load on engine?

The fact that you say you got it on the highway and then temp gauge was lower than middle makes me think thermostat. VAG your car, see what the freeze frame is. Also look at the temperature readings, log your car. That's what I did for mine (bad tstat)

[IKE20VA4]

simple question, what should I check?

what i have found on web so far, most suggested is to check thermostat, but I think it's fine because car warms up normally and and reaches middle temps on the gauge.

I got this error when i was on highway, it was cold outside, 12 Celsius. I don't remeber but I think temp gauge was lower than middle, could it be caused just by low temperature outside and without any load on engine?

So it had warmed up normally prior to your CEL?
I'm pretty sure my tstat is bad because I have to be going up a long hill in 45 degree F temps with the heat on to get the gauge to reach middle. That and I have already done the coolant temp sensor. Got the tstat and tbelt/water pump on the way and planning a marathon weekend of some DIY work. It's gonna be not this weekend but next though.

[NODO-GT]

Will post Freeze data later.

Today in the morning, when i started car, it started right away at idle revs, as if it didn't need warming up... I guess tstat has failed.

[Charles.waite]

^^ the lower revs is actually normal when its really cold out. Sounds like a t-stat to me. How long does it take to get up to temp? And if it drops at all from the middle under any circumstances, you've got a bad t-stat.

I put together a somewhat marginal, but possibly useful DIY a while back. Might help you some.

http://www.audizine.com/forum/showth...ical-Questions

[pDubs]

I've got the same code right now. My car never gets half way to operating temperature and takes forever to even budge warming up at all. I have ruled mine down to replacing the thermostat which is on the way in the mail now. After a bunch of research I think this code pretty much means its your CTS or your T-stat.

[CystmX]

I've got the same code right now. My car never gets half way to operating temperature and takes forever to even budge warming up at all. I have ruled mine down to replacing the thermostat which is on the way in the mail now. After a bunch of research I think this code pretty much means its your CTS or your T-stat.

PDubs, what do you say we knock this out together? I have the code also and I think it's my CTS because my gauge never reaches half way anymore and the needle drops when I go up hill.

[NODO-GT]

I got Freeze Data today.

[quickaudi07]

Looks like your thermostat got stuck open, I would get that replaced.

[NODO-GT]

Looks like your thermostat got stuck open, I would get that replaced.

thanks for the replay.

I'm interested how did you identify that it stuck open? which value points it out?
just want to learn more :)

[pDubs]

If the car is never heating up to operating temperature then one thing to look at is the thermostat being stuck open. The coolant in cars is always flowing throughout the motor, once the thermostat reads it needs to be cooled down a bit it opens up and allows coolant to flow through and be cooled in the radiator and continue to flow back through the block. Once its cooled enough it will close. If the thermostat gets stuck closed your car will overheat, if it gets stuck open then your car will never really get up to operating temperature and be running too cold.

[pDubs]

PDubs, what do you say we knock this out together? I have the code also and I think it's my CTS because my gauge never reaches half way anymore and the needle drops when I go up hill.

Yeah I still haven't done mine. I don't think it's the CTS though I think its the thermostat.

[Charles.waite]

Yeah I still haven't done mine. I don't think it's the CTS though I think its the thermostat.

Its more likely to be the thermostat, but it could be the CTS. My bet is on the thermostat though. Reference my thread, i had the exact same problem:
http://www.audizine.com/forum/showth...ical-Questions

[bman005]

Its the thermostat. Temp should be at least 80C in closed loop while driving. Sensor failures typically will give you a much colder reading (a negative temp) You can easily check your sensor with vagcom (assuming you have or have access to one). When the car is completely cold like after it has sat overnight do a key on temp check. Check coolant temp and ambient air temp in measured values, they should be with 3 or 4 degrees of one another. If not, one of the two sensors is off

[CystmX]

Yeah I still haven't done mine. I don't think it's the CTS though I think its the thermostat.

Ok, I'll order the part and some coolant and we can knock this out together sometime. PM me.

[bobmin]

So, if your temp gauge has suddenly started not reaching the staright-up position BUT you don't have the code, is it still likely that the thermostat is stuck open or would that indicate a sensor? The heater gives off plenty of warmth within a mile of startup.