P2181 Coolant Performance Issue - Suggestions??
03-16-2015, 12:04 AM
#11
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Thanks for the reply. The heater is working normal and when the fans are blowin like this the temperature stays on the c and when it's not its right in the middle .. I changed the sensor and the thermostat this weekend and so far so good !
01-24-2020, 01:13 PM
#12
Cooling system performance
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
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
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Kris3527 (10-27-2020)
08-18-2020, 05:33 PM
#13
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Question
06-08-2021, 04:41 AM
#14
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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
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
05-16-2022, 10:05 AM
#15
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Same issue
I am have the same issue. Fans are always running on high speed, I changed my water pump, fans and fan module, and auxiliary pump. Could this be wiring? And if so where?
05-19-2022, 09:01 AM
#16
AudiWorld Senior Member
2006 B7 A4 quattro 2.0T 215k miles. Third owner and head muckity muck.
Kel,
Sort of the same thing happened to me upon refilling the cooling system after some maintenance. The fans would run all the time. Turns out it was a trapped air bubble in the system.
To purge air:
From cold,
Kel,
Sort of the same thing happened to me upon refilling the cooling system after some maintenance. The fans would run all the time. Turns out it was a trapped air bubble in the system.
To purge air:
From cold,
- remove coolant reservoir cap.
- start car
- set cabin heater to max temp
- set cabin fan to low
- let car warm up to normal operation temp (temp gauge needle at center of span)
- top up coolant as needed.
- shut off car
- reinstall reservoir cap.
- let system cool naturally to ambient
- it may take a few tries.
Last edited by Hayabusafalcon; 05-19-2022 at 12:35 PM.
05-21-2022, 07:37 AM
#17
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Tthank you so much! Does car have to be running or just on, without pressing breaks I mean.
2006 B7 A4 quattro 2.0T 215k miles. Third owner and head muckity muck.
Kel,
Sort of the same thing happened to me upon refilling the cooling system after some maintenance. The fans would run all the time. Turns out it was a trapped air bubble in the system.
To purge air:
From cold,
Kel,
Sort of the same thing happened to me upon refilling the cooling system after some maintenance. The fans would run all the time. Turns out it was a trapped air bubble in the system.
To purge air:
From cold,
- remove coolant reservoir cap.
- start car
- set cabin heater to max temp
- set cabin fan to low
- let car warm up to normal operation temp (temp gauge needle at center of span)
- top up coolant as needed.
- shut off car
- reinstall reservoir cap.
- let system cool naturally to ambient
- it may take a few tries.
05-21-2022, 10:41 AM
#18
AudiWorld Senior Member
Kel,
Yes definitely start the engine.
The procedure is common to many VW's and Audi's. It worked for both my A4 2.0T and our Jetta 2.0
Or, you can simply drive around under light throttle too if you like. Drive it around the block a few times. But then let it cool down completely. It may take repeated cycles but this does work.
See my link below:
https://www.audiworld.com/forums/a4-...-came-3033700/
(Or you could use the Audi purge tool. But you probably don't have that tool. I don't either.)
Yes definitely start the engine.
The procedure is common to many VW's and Audi's. It worked for both my A4 2.0T and our Jetta 2.0
Or, you can simply drive around under light throttle too if you like. Drive it around the block a few times. But then let it cool down completely. It may take repeated cycles but this does work.
See my link below:
https://www.audiworld.com/forums/a4-...-came-3033700/
(Or you could use the Audi purge tool. But you probably don't have that tool. I don't either.)
Last edited by Hayabusafalcon; 05-21-2022 at 10:51 AM.
05-21-2022, 10:57 AM
#19
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Thank you appreciate your help in this. I never worked on any cars before, the reservoir cap is the cap on the coolant container correct? That has the pink liquid.
Kel,
Yes definitely start the engine.
The procedure is common to many VW's and Audi's. It worked for both my A4 2.0T and our Jetta 2.0
Or, you can simply drive around under light throttle too if you like. Drive it around the block a few times. But then let it cool down completely. It may take repeated cycles but this does work.
See my link below:
https://www.audiworld.com/forums/a4-...-came-3033700/
(Or you could use the Audi purge tool. But you probably don't have that tool. I don't either.)
Yes definitely start the engine.
The procedure is common to many VW's and Audi's. It worked for both my A4 2.0T and our Jetta 2.0
Or, you can simply drive around under light throttle too if you like. Drive it around the block a few times. But then let it cool down completely. It may take repeated cycles but this does work.
See my link below:
https://www.audiworld.com/forums/a4-...-came-3033700/
(Or you could use the Audi purge tool. But you probably don't have that tool. I don't either.)