Just recently, my temperature guage has started to show varying temperatures. 
Prevoiusly, the car used to warm to 90deg and that was it. Hot or cold, it warmed to 90 and stayed constant. In extreme heat 40deg+ the oil temp would rise (113 was the highest I saw), but the temp guage sat at constant 90.

I first noticed it on a trip to the Australian snowfields after about 20mins the temp guage had barely reached 60. The guage seems to be reading roughly the same as the oil temp. The car heater seems to be working just fine.

Around town the guage seems to hit 90 and pretty much stay. 

if I work the engine hard the temp will rise, but then drop.

it seems to be highway trips in cooler temps.

This may not be unusual, but it would be nice to hear from those in cooler climates.

im a little concerned my thermostat could be stuck wide open. 

Is your car a dsg? 

 

It's quite common that the inline thermostat to the oil cooler for the gearbox can stick open, causing the above symptoms.

Car is indeed a dsg 

Hi, its a common problem.......search for DSG thermostat problems.....not high cost and can be done by a DIY mechanic.

Replaced the part - thermostat beside the DSG. Took about 60min. Easy to install, Barely lost any coolant.
Problem solved.

Wanted the part fast so ordered from VW. $85aud

Edited 30 August, 20223 yr by Rkdee

@Corbarwolf might find this thread useful. 

finally, there qas me thinking I had to drive over 10 miles to even get the car warmed up was 'normal'. Will get this sorted ASAP with the winter coming. 

On 07/08/2022 at 23:40, Rkdee said:

Just recently, my temperature guage has started to show varying temperatures. 
Prevoiusly, the car used to warm to 90deg and that was it. Hot or cold, it warmed to 90 and stayed constant. In extreme heat 40deg+ the oil temp would rise (113 was the highest I saw), but the temp guage sat at constant 90.

(Irrelevant to your case, but be aware the VAG uses software to keep that temperature gauge at exactly 90 when the real coolant temperature is between ~75 and ~110°C.... If you want to know the actual coolant temperature, you need VCDS or a general OBD device)

Edited 16 November, 20223 yr by andrehj