Have 04 golf 2.0 ck engine light on code p2181 put new water pump new temp sensor light still on not running hot car running fine what else can it be

I am sure it is a thermostat for a P2181

It is possible, how ever, I would check for inop coolant fan, or restricted radiator. If parts of the radiator are cool to the touch when the coolant fan has kicked in, very possibly resricted flow of coolant through the radiator.

P2181 - Performance Malfunction in Cooling System
Possible Solutions
* Check Engine Coolant Temperature Sender (G62)
* Check Coolant Thermostat
* Check Engine Cooling System
o Put the key on, fan speed on 1, and push the a/c switch. Are both fans kicking on? If not, you found the problem.
o Put the key on and fan speed on 1. Does heat come out readily from the vents?
+ No. Probably the water pump is gone.
+ Yes. Probably the thermostat is gone. good- luck!!

Trouble Code: P2181

Cooling System Performance Malfunction
Possible Causes:


ECT sensor has failed ECT Sensor (on Radiator) has failed ECT sensor signal circuit is open (inspect wiring & connector) ECT sensor signal circuit is shorted Cooling system malfunction, or the thermostat is stuck Engine not operating at normal operating temperature EOT sensor is damaged or it has failed

Hi,first thing your cambelt and tensioner should have been replaced 13k miles ago,it would pay you to replace the water pump at the same time as they are known for impellor failure = cooling system fault=P2181 code,hope this helps.
Darren

when you removed the water pump, did you disturb the timing in anyway ???

Im actually going through the process of fixing this problem with my car. the P2181 is a performance cooling error, usually brought up by thermostat, radiator issues, or ECT sensor. You should narrow it down and check both radiator and thermostat to prevent later issues. If all is well go to your local autozone, pep boys, checkers..etc. and have them erase the DTC error. If you are looking for a more long term solution you can purchase many different software such as VAG-COM or any other software used to run test on vehicals. Be sure you know what you are doing though because messing with your cars computer can have long term effects that can be pricey.

P2181 is a overheating engine.  
Can be:
Bad fan themoswitch, temp sensor themostat water pump impeller fan motor or fuse on battery
check to see if fans work by turning on Air Conditioner (fans should run with A/C on). Turn A/C off, warm engine, check to see if fans come on, if they do NOT it may be thermo switch on radiator on lower left side, has 3 wire plug, takes 1-1/8" wrench/socket to remove.  This thermo switch controls fans when temp reaches 195F, if fans do not come on at engine temp 190-195F try  replace switch VW part number: 1J0-959--481-A  You can verify if the switch is bad by shorting wire 1 and 2 (fans should come on when jumpered).

pull codes from on board diagnostics turn key on not running press and hold hot button on temp and off at same time till dash lights up write down codes respond with all computer codes i will help you determine prodlem and try to fix

Ive experienced something like that when the "Heater" under the dash is blocked!
(jseidlich yours sounds more like a broken Temp.sensor;)