1.8T coolant temp sensor

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georgie
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1.8T coolant temp sensor

Post by georgie »

Hi all,

Had a coolant temp sensor go faulty recently. Cleared the code and the car went back to warming up as normal, but it came back after a few days. Bought a replacement sensor from GW and fitted it, a month later and its doing the same. I can get on oem one from VW today for R900, but I'm not sure if the sensor is the problem. Why would the previous 2 work fines after the fault is cleared? Can the topfran sensor from gw really die after just one month?
07 PGTi
Ex: 11 BMW 320d
Ex: 12 Cross Polo 1.6
Ex: 15 Fiesta ST
Ex: 04 Jetta 1.8T
Ex: 99 Golf VR6
Ex: 87 Fox 1600
Ex: 99 Polo 2.0 16v (ITB's, cams, etc)
Ex: 05 Fiesta ST, 00 Sentra 200gsi, 04 citi 1.4i, 94 Corolla 180i GSE ,92 cti, 73 Escort Mk1 4AGE twincam
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georgie
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Re: 1.8T coolant temp sensor

Post by georgie »

Replaced the cts with a new oem part on Friday. P0116 error appeared again today.

Symptoms from the start is the temp needle would reach 90deg much quicker than normal, and the car stopped doing proper cold start in the morning (start and immediately revs drop to about 900). Also heavy on fuel and slightly rough idle.

I never got any CEL and the needle didnt do anything strange aside from rising too quickly. No overheating or using coolant either. There doesnt seem to be any damage to the wires on cts.

This all goes back to normal after i clear the error, and stays fine for another day or two.

Should i replace the thermostat or is there something else to check? The confusing part for me is that it runs fine after clearing the code.
07 PGTi
Ex: 11 BMW 320d
Ex: 12 Cross Polo 1.6
Ex: 15 Fiesta ST
Ex: 04 Jetta 1.8T
Ex: 99 Golf VR6
Ex: 87 Fox 1600
Ex: 99 Polo 2.0 16v (ITB's, cams, etc)
Ex: 05 Fiesta ST, 00 Sentra 200gsi, 04 citi 1.4i, 94 Corolla 180i GSE ,92 cti, 73 Escort Mk1 4AGE twincam
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THANAS
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Re: 1.8T coolant temp sensor

Post by THANAS »

Check the wiring, remove the insulation around the plug and look for breaks.
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georgie
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Re: 1.8T coolant temp sensor

Post by georgie »

THANAS wrote: Tue Jul 20, 2021 6:53 pm Check the wiring, remove the insulation around the plug and look for breaks.
Shot thanas, will take a closer look
07 PGTi
Ex: 11 BMW 320d
Ex: 12 Cross Polo 1.6
Ex: 15 Fiesta ST
Ex: 04 Jetta 1.8T
Ex: 99 Golf VR6
Ex: 87 Fox 1600
Ex: 99 Polo 2.0 16v (ITB's, cams, etc)
Ex: 05 Fiesta ST, 00 Sentra 200gsi, 04 citi 1.4i, 94 Corolla 180i GSE ,92 cti, 73 Escort Mk1 4AGE twincam
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georgie
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Posts: 2762
Registered for: 17 years 11 months
Car Make: VW
Car Model: 07 pgti
Membership No: missing
Location: Cape Town

Re: 1.8T coolant temp sensor

Post by georgie »

THANAS wrote: Tue Jul 20, 2021 6:53 pm Check the wiring, remove the insulation around the plug and look for breaks.
Removed the insulation and found no visible damage to the wiring. After the last reset the fault didnt come back until yesterday, so it was gone for over a month. Started the car and heard the revs immediately drop instead of cold starting. Cleared the fault again and all is back to normal. Very confusing :???:
07 PGTi
Ex: 11 BMW 320d
Ex: 12 Cross Polo 1.6
Ex: 15 Fiesta ST
Ex: 04 Jetta 1.8T
Ex: 99 Golf VR6
Ex: 87 Fox 1600
Ex: 99 Polo 2.0 16v (ITB's, cams, etc)
Ex: 05 Fiesta ST, 00 Sentra 200gsi, 04 citi 1.4i, 94 Corolla 180i GSE ,92 cti, 73 Escort Mk1 4AGE twincam
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