Is there anyway to tell whether its the temp sender or thermostat

[mcgee9t2]

as above, know i need to replace either temp sender or thermostat, is there anyway to determine which it is to save me replacing both...

[WadGTI]

I replaced my temp sendor as I was having an error in the ECU cooling map. IN the end it was my thermostat.

Symptons - Temp guage running around 75 approx on motorway runs and usually slow driving/standsill, rose to the normal 90. But then would drop to 75 upon normal driving again.

[Rhyso]

You can log the temp via vagcom

Or see if an error code is thrown up in Instruments; module 17

[mcgee9t2]

WadGTI - I belive those sympoms happen when either the temp sender or tstat goes...? I have those symptoms but not sure if its tstat or temp sender.

rhyso -no copy of vag com... one of my mates has it but doesent know how to use it... no codes when iv plugged the code reader in...

[dom]

You can remove the thermostat and test it in a pan of water.

My money would be on the stat being to blame rather than the sensor.

[mcgee9t2]

any guides on how to log temps on vag com?

im taking it that when you log temps that's the temp seen by the temp sender and therefore if the readings constant its t/stat that's knakerd? (or the other way around)

and dom, how woul I test it in a pan of water? (sorry to sound like an indiot, could proberbly work it out if I took the tstat out and had a look at it but aint got time to do that ATM...)

Cheers

[dom]

Have a look at this:

http://www.youtube.com/watch?v=aa1yG-fntRk

[DaveT]

Took my mk4 GTI into VW today with the symptoms described above where the needle sits at approx 75 degrees on long runs. They changed the temp sender as it was showing up as being faulty. This did not cure the problem and so tomorrow is going in for a new thermostat. Hope this helps.

[northeast_gti-t]

Have no Fault codes for mine on vag-com,mine heats up slow ie top hoses/heater hose gets real hot and the lower takes ages to get hot so i'm going for a thermostat also my gauge sits at cold all the time until its been sat at idle for a long time

[WadGTI]

any guides on how to log temps on vag com?

im taking it that when you log temps that's the temp seen by the temp sender and therefore if the readings constant its t/stat that's knakerd? (or the other way around)

and dom, how woul I test it in a pan of water? (sorry to sound like an indiot, could proberbly work it out if I took the tstat out and had a look at it but aint got time to do that ATM...)

Cheers

Lol. It does sound like thermostat btw. They are cheap as chips. I picked one up from ECP for £6. I would get one and change it and then see where you are with things.