[Vlad_I]

So... ive got about 52,000km on my fast.
Apart from other typical malfunctions (A/C, runner control motor...) there is a reoccuring one: engine coolant temp sensor. Now i had it replaced at the same time as the intake manifold runner control motor at my local VW dealership for a ton of money about 1000km ago.
On saturday the CEL came on and guess what, its the sensor AGAIN (scanner confirmed). Ive got an appointment for this friday to have it looked at (and i mean replaced) but im starting to think the problem may lay deeper.
Im thinking it could be the thermostat but any advice would be appreciated. I will be checking my cam follower the same day as well to be on the safe side.

 

[07GTIMYFAST]

I don't know how a sensor failure could be caused by the thermostat, only thing could be just a bad sensor or bad wiring to the sensor. if you know someone with vag-com when you drop in the sensor do some data-logging of the engine coolant temp from startup- to operating temp and awhile after that to see when the thermostat opens and how steady it keeps the temp.

 

[volcano]

mkiv get a coolant code that is caused by the t-stat

but im not sure if it the same on the mkv

 

[Vlad_I]

I do, in fact, know someone with a VAG-COM and will follow the given advice. The reason im a little skeptical about the whole sensor issue is because this dealership ripped me off big time when i went in for repairs and i have a slight feeling that the sensor was never really REPLACED so we shall see... If they start blaming everything on the thermostat i will just order all parts on-line and either spend the weekend learning my way around FSI or get my friend to do it for fraction of the price.

 

[Vlad_I]

Got my fast back from the shop today. Turns out the only reason CEL was on is because of the EVAP system messege... should tighten that gas cap more often. Surprisingly though the mechanic said no record of a malfunctioning coolant temp sensor was found :s I definately saw it on the scanner last weekend... Oh well.
They were nice enough to run a full EVAP diagnostic for free.
Also checked cam follower (its good), and got the stereo software update so no more bass issues for me.