Coolant temp

[Patrick2691]

I know there's a few similar threads on this. Yet none with the answer i was looking for. The car takes a while to warm up but read that was a typical VW thing. Logged it on vcds and when the gauge reads 90 the coolant temp is only at 70 and doesn't get higher than 80 after a good amount of driving and can fall again. Gauge will read solidly at 90 and not fluctuate. Air temps are 4-5' Celsius today.

Slightly stuck open thermostat or something else? Also how will I know which one of the two thermostats it is?

[dazza]

Sounds like the main thermostat.

[shail]

I was always told that the gauge will read 90 but the actual temp is 70-90.   Something to do with drivers getting worried if the gauge keeps fluctuating. 

[dazza]

After a good drive the actual temp should be around 90º my actual temp is around 93º unless i'm hooning around.

[Kieran1990gti]

Have you noticed a mpg drop

[Bo!]

Patrick2691
How long does it take to warm up .
There are also inline stats on these motors that fail which may be a cause,
worth doing a search on this food for thought .

[Pesky jones]

I was under the impression that if it takes ages to get to 90, but stays there when it does then its inlines.

If it rarely gets to ninety and fluctuates a lot then its main stat

[r5gtt]

Could be this one and if dsg then the one above the gear box.

http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.0.html

[dazza]

I think you need to look at the actual temps my gauge gets to 90 when the actual temp is about 74. Went up to the snow last week and after 10 mins engine and coolant temps were sitting nicely at 93º

[r5gtt]

Found this on another forum.

I think it works on dual climate control vehicles but never tried it on mine as I keep on forgetting to. 

This is a pretty cool trick if you have dual climate control. It's not in the owner's manual. If you press the "AC" and upper climate control button (the one with the ↑ on it) at the same time, you will notice the temp screen change to a number. It starts at 0.0. The driver one and the passenger one both change. If you turn the driver's temperature knob to the right, the numbers on the driver's side will change from 1.0 to 25.0. With the fan center knob you can change the decimals, .1, .2, .3 etc. Depending on what number the driver's side is at, the passenger's number indicates a certain reading. Those are speed, outside temperature, etc. Here is the layout of what each one means. The left one is the number shown on driver's side, the right is what you the passenger's number means respecitvely. Sorry if it sounds confusing.

.0 : Outside temp - front bumper
4.1 : Outside temp - roof
4.2 : Outside temp - rear bumper (inside temp?)
15.0 : Oil temp
19.0 : Uncorrected speed (Kmh)
19.1 : Uncorrected speed (Mph)
19.2 : Coolant temp
19.3 : Tachometer
19.4 : oil pressure
25.0 : Voltage