G62 Coolant Temperature sensor placement 2.0TDI BMM Engine

[andreasw]

Hello! 

I have a fault code for my coolant temperature sensor p0118. From what i've read it seems to be a normal fault to become faulty. Now to my problem, where the heck is it? I uploaded a picture of the engine, and another picture where I think it might be. But nothing happened when I disconnected this one. I found the intake sensor, and the temperature skyrocketed when the sensor was out.

[nige8021]

#5 

[andreasw]

Below the Diesel pump? Thanks for the clarifying picture.

[nige8021]

#9 is the hose from the top of that radiator so easy to follow that back 

[andreasw]

13 minutes ago, nige8021 said:

#9 is the hose from the top of that radiator so easy to follow that back 

Thanks for the help. Do you also have the part number for Cambelt Replacement Kit? And Water pump? 😊

[nige8021]

https://skoda.7zap.com/en/cz/octavia/oct/2007-419/1/109-109000/#4   Kit with tensioner/roller/belt  03G 198 119 A 

[nige8021]

https://skoda.7zap.com/en/cz/octavia/oct/2007-419/1/121-121035/#1   038 121 011 J 

[andreasw]

On 08/09/2022 at 20:18, nige8021 said:

https://skoda.7zap.com/en/cz/octavia/oct/2007-419/1/121-121035/#1   038 121 011 J 

Thanks for the part numbers!

 

This placement is really annoying. Very limited space. I dont think I will be able to get it out without disconnecting some of the water hoses. How is this procedure supposed to be done on this BMM engine? There is a hard plastic housing in the vicinity of the sensor. I guess its a gasket between the engine and this? It would be much easier to replace if I remove this. But I might get away with just disconnecting the house above the sensor. How have you done this procedure, need a little help 😅

 

[Guest]

AFAIK the sensor is retained by a U-clip and seals with an O-ring.

 

Slide the clip out and pull the sensor out being careful to retain the O-ring, not necessarily for reuse but to keep track of parts.

[andreasw]

Has anyone changed this on a BMM engine? Seems like alot of hassle to change it without removing the housing. Theres too much stuff in the way to remove it without removing alooot of stuff. 

Since writing this thread, the engine check light turned off and the temperature sensor started working again. Is that possible with a faulty sensor? Or is it bad wiring? 

[skomaz]

Could just be a bad connection at the plug and in trying to get it off you've disturbed it enough to make the connection again.

 

I didn't do on on my old octavia 4x4 BMM but did do one on a Fabia tdi and that was by feel alone unsighted 

[Twostrokemick1]

The sensor is easy to replace. Getting

the plug detached from the sensor is a bast*rd. I broke the wires on mine. If changing the sensor change the plastic housing also because it will leak in the not to distant future

 

[andreasw]

18 hours ago, skomaz said:

Could just be a bad connection at the plug and in trying to get it off you've disturbed it enough to make the connection again.

 

I didn't do on on my old octavia 4x4 BMM but did do one on a Fabia tdi and that was by feel alone unsighted 

I don't know if I touched the wires all the way back there. Anyway the light is on again, and so are the cooling fans. 

7 hours ago, Twostrokemick1 said:

The sensor is easy to replace. Getting

the plug detached from the sensor is a bast*rd. I broke the wires on mine. If changing the sensor change the plastic housing also because it will leak in the not to distant future

 

Well in this case even after removing the airbox it looks almost impossible to change it. There's a metal pipe that takes preheated air into the airbox that's really close to the sensor. Best way looks like draining coolant, remove the housing and change the sensor outside of the engine bay. I broke the tab on the connector to the sensor though... So maybe I'll put some glue or zip ties to hold it in place. 

[andreasw]

I've gotten the sensor out by draining fuel and a bit of fiddling. I've taken a resistance reading, the old one was ~2600ohm and the new one ~2200ohm. That sounds like it's within spec right? 

[andreasw]

Can this fault code be produced by any other sensor? 

[andreasw]

I found a broken wire. Is this the color for the sensor? Unfortunately I'm colourblind and have no chance to check what cable colour is at the sensor. I guess I could fix this and hope for the best. 

[Breezy_Pete]

Circuit diagrams say brown/grey,  and red/grey are the two wires for G62.  I think that could be what's in your picture, yes.

[Breezy_Pete]

Red/grey from pin 1 of sensor connector finishes at engine ECU pin 52,  brown /grey from pin 2 goes to ECU pin 53.

 

[skomaz]

7 minutes ago, Breezy_Pete said:

Circuit diagrams say brown/grey,  and red/grey are the two wires for G62.  I think that could be what's in your picture, yes.

 

I don't have the circuit diagrams but agree re the pictures showing those colours.  And a break like that would cause the issue. 

 

Either way it ought to be fixed regardless of what it is. 

[andreasw]

I didnt have any solder sleeves, so I used WAGO connectors just to see if this was the issue. When I first started the car the fans started blowing but they stopped shortly afterwards, then I cleared the fault codes and it seems to have fixed it. Dont know if it was because i replaced the sensor or connected the broken wire. I had to tug a little for it to break, but it was also badly corroded. So I guess it was totally separated. 

Lets see how long this "fix" lasts 😆 

[Breezy_Pete]

I reckon about 9 out of 10 'sensor faults' turn out to be wiring failures/damage on Skodas.

[andreasw]

3 hours ago, Breezy_Pete said:

I reckon about 9 out of 10 'sensor faults' turn out to be wiring failures/damage on Skodas.

I watched a video for another VAG car, I looked at the same spot where his cable had snapped and found it in the same place.