17698 - Coolant Temp Sensor at Radiator Outlet (G83): Signal too Small

[casiodan]

Hi guys.

I have recently had the coolant temperature sensor housing replaced after a rather steamy incident a couple of weeks ago, since then the temperature gauge has not been getting right up to normal operating temp, normally bang on 90.

I thought it may have been the sensor that had gone faulty but im not convinced.

The car is acting as if the thermostat is stuck open. Im sat here now with it idling at about 60deg and when im driving it fluctuates, sometimes upto 90 and sometimes right down near the 50 mark.

Its a 2002 1.8t a4.

It just seems a little odd that before the housing popped on me it was fine and now with the new housing on its overcooling. Why would the thermostat go exactly when the temp sensor housing was replaced.

I run Vag com and got the fault code 17698 - Coolant Temp Sensor at Radiator Outlet (G83): Signal too Small which i cleared but it came back after a few minutes. Could the radiator outlet sensor cause the overcooling issues.

Any thoughts anyone, i don't want to start taking the alternator off to change the thermostat if its not likely to be faulty.

Many thanks

Dan

 

[TonyH50]

Have you tried using VAG com to monitor Engine Coolant Temperature and Radiator Outlet Temperature as it warms up (Measuring Group 130). My A3 8P showed the difference in temp between the two to be no more than 8 deg C. Changed Thermostat and now engine warms first before opening thermostat.

 

[CHRIS555]

I recently had a similar problem and just changed my temp sensor and problem solved - more power and more mpg!