Coolant Temperature Sensor

[Chris56]

I need to replace the coolant temp sensor on a 2006 diesel tourer. I have searched the web and can't find where it is located in the engine bay - does anybody know where it is located?

 

[edgeoftime]

QUESTION? is reading low or not at all, if it's low they all do.

 

[Chris56]

Its actually a weird one John, It reads normal but sometimes it seems to stick. Reads zero whilst car is warming up but then rises quickly.

I made another post about car going into limp mode without throwing up a warning light/code. Its been happening only since I had it remapped. Fahad has suspected it may be temp sensor as car has had an egr-delete and egr operation is related to coolant temp. Was just a possibility until I noticed last week that I had been sitting in traffic for ages and it was stuck oin zero. I shut down/restarted the car and it went into limp mode. I restarted the car again and it ran normally, with the temp gauge reading normal. Its only a £10 part so was going to try it until I am able to get up to Fahad's.

 

[freddofrog]

I've no idea where the sensor is, but you can monitor it by using the aircon diagnostic system, the engine coolant temperature is sensor 4

instructions below (click to enlarge)

 

[Chris56]

Thanks for that Brian - that was really helpful!

I tried it on my way to work this morning. Route was through town but there was little traffic. and managed to get to the following data:


Time (mins) Temp
0 12 - temp gauge not moved
1 14

steady rise, but slow to rise through 30s


8 47 - temp gauge starts to move from zero
9 50 - temp gauge on minimum
10 52
11 52

steady rise again

15 63 - temp gauge now in middle
16 65

Does this look normal?

 

[freddofrog]

I would say that, for a diesel, the numbers look normal, make the drive a bit longer and it should reach upper 70's.

I've no idea about how the gauge on the dash works, but it may not be correlating properly with the real values.

btw, I forgot to say that you can leave the diagnostic mode on while driving, it looks like that's what you did

 

[Chris56]

These readings were taken when driving, hence the gaps in the data as I couldn't write them down!.

Im about to finish work soon so I plan to do it again but with the car stationary to see where the readings go. I know it will get into the 70s since thats what Fadad had to get it to in order to remap it.

Thanks for your help and advice Brian - if the results suggest the sensor it functioning properly then I can rule that out as a probable cause of it going into limp mode.

 

[Chris56]

Did a further test yesterday - temp increases linearly and then flattens at 77 degrees (then I ***ume the thermostat opens around this point)

Don't think the sensor is the problem