Temperature Sensor problem?

[Capoeirista]

Hoping you can help me out. I've noticed that on cold starts my SAI doesn't kick in. Normally I can hear the SAI and then it turns off after a minute or so after starting, but now I don't hear it at all.

I've also noticed that when I turn the car on again (after driving and engine is warm), the temperature gauge resets back to 0. It then takes about 5 minutes to go back to normal running temperature (1/2 on gauge).

Could the above be a fault with the temperature sensor or is there an issue with the thermostat?

I don't want to have to go to the VW dealer and then have them rip me off if it is just as simple as changing the temp. sensor.

Thanks

[vdubmotorworx]

Are all the coolant pipes hot after driving for a while? if some are cold or cool then thernostat mate...VDUB..

[Capoeirista]

Thanks VDUB. I'll check it when I drive to work tomorrow.

[Capoeirista]

Thanks VDUB. I'll check it when I drive to work tomorrow.

Hey VDUB, the coolant pipes were hot after driving to work. The temp gauge still works and runs on normal temp when driving. I've got a feeling that it might be the coolant temp. sensor after reading up on a few other fourums. I'll go down to VW Essendon and buy the part (It shouldn't be over $30-$40 hopefully) and change it over and see how it goes.

FYI, I've got a 2006 Polo GTI and done just over 80K km. I wonder if this has happened to anyone else?

[Capoeirista]

Changed over the coolant temperature sensor, but no change. Temp. gauge resets to 0 after turning car on even when warm. I think you're right VDUB, I think it is the thermostat. Just found this thread:
The Volkswagen Club of South Africa - View topic - Polo GTI Temperature question
I'm a bit of a noob. Is changing the thermostat an easy job? Is this the right part? Coolant regulator, thermostat - 044121113

[vdubmotorworx]

usually when the thermostat is stuffed it will show 90oc at idle with a hot engine and then when you drive off the temp drops by about half then when you stop it goes back to 90... if all your pipes are hot thermostat should be ok....if it resets to zero with ignition then points to more of a electrical issue...VDUB...

[Capoeirista]

Thanks VDUB. I can't believe VW Essendon charged me $73.00 for the CTS! Can you recommend a good place in Melbourne I can take the car without having to pay an arm and a leg?

[vdubmotorworx]

sorry mate dont know the melbourne people

[Capoeirista]

Hey VDUB. Turns out it was the Coolant temp Sensor. I got my colleague to bring his Trouble code reader and it spat out code: 16500 P0116 'Engine Coolant Temperature Circuit-Range/Performance Problem'. Once he cleared the code, I turned the car on and the SAI kicked in (would not turn on for cold starts). Will test the temp gauge reading when I drive home after work. Being the noob I am, I didn't realise I had to clear the code after installing the new CTS.

[vdubmotorworx]

depends on the fault... sometimes yes ..a erase of the code is required...VDUB...

[noone]

Temperature Sensor problem?

Nothing wrong with being fresh, I'm still very knowledgeless despite my efforts.

[Capoeirista]

Thanks noone. All a learning process for me I guess. I've read heaps of your posts and you seem to know quite a lot.

[louis19]

Did you end up finding the problem? I have the exact same issue, can get it to 90c, turn it off and even if I turn it Back on instantly it returns to 0c. Also don't hear the SAI anymore on cold start ups. All coolant pipes are warm and no fault lights are coming up.

Any ideas?

Hoping you can help me out. I've noticed that on cold starts my SAI doesn't kick in. Normally I can hear the SAI and then it turns off after a minute or so after starting, but now I don't hear it at all.

I've also noticed that when I turn the car on again (after driving and engine is warm), the temperature gauge resets back to 0. It then takes about 5 minutes to go back to normal running temperature (1/2 on gauge).

Could the above be a fault with the temperature sensor or is there an issue with the thermostat?

I don't want to have to go to the VW dealer and then have them rip me off if it is just as simple as changing the temp. sensor.

Thanks

[h100vw]

The SAI doesn't have to run every start, although they often come on on the first start of the day. Even with mine removed and coded out, I can hear the relay click pretty often.

Gavin

[louis19]

The SAI doesn't have to run every start, although they often come on on the first start of the day. Even with mine removed and coded out, I can hear the relay click pretty often.



Gavin

Thanks Gav, any explanation for the temp gauge resetting to zero and then slowly moving back up to 90c everytime I turn the car on even once the cars warm?

Edit, I have made a video of what's happening too: Gti Polo Problem: Gti Polo Problem - YouTube

Any help is appreciated