How to diagnose a faulty thermostat?

[jakm15]

Is there a way to dertermine if my thermostats are faulty with VCDS? My temperate guage never rises to 90 unless I'm really pushing the engine, after many hours researching various sites I've found a lot of conflicting advice to weather this is normal not.

I've found the parts that I need and they are only £38 for them both but it's the time I don't want the waste changing them if they are not faulty.

I've monitored the coolant temperature when driving and it gets to around 75C when doing about 85mph, at normal round town driving it's about 68. My engine is a 140 CAGA 2.0tdi mapped to 180.

Sent from my moto e5 plus using Tapatalk

 

[maxpayne]

I’d be interested to know too. Coolant temp reaches 90 easily for me when driving in town but on motorway doesn’t go beyond 70!

 

[stevey83]

Faulty thermostat for sure. My TT used to do this, wasnt fully opening. Once changed soon rose and sat at 90.