Vr6 Water temp gauge reads too low...sender or 'stat?

[lard44 0]

Hey all,

 

Really chuffed with the vr6 I picked up this morning...but noticed on the long drive home that the temp barely touched 70 degrees, and when cruising at 2.5k less. The needle IS moving, and was fine on the test drive a week ago. Doing searches brings up two options...either a constantly open stat, or a faulty sender.

 

Fan is blowing hot air after a couple of minutes as it should, does this help diagnosis?

 

Cheers all,

[nrc 0]

The coolant gauge is controlled by the yellow temperature sender in the thermostat housing. Try removing the connector and giving both it and the sender a blast with WD40, see if that helps.

[seanl82 23]

Does it rise when in traffic or stood still? If it does, but drops down again when in motion it would point to a faulty stat.

[lard44 0]

Does it rise when in traffic or stood still? If it does, but drops down again when in motion it would point to a faulty stat.

 

Yup, that's exactly what it does...right, looks like I'll be doing some shopping then...

[Jim Bowen 1]

Exactly the same as mine. Might change it tomorrow then. Just never got round to it. As everything else was ok

[P3rks 11]

Surely if your travelling at speed, on the motorway with low RPM, when it's freezing cold outside you'll get lower water temps because of all the cold air shooting over the radiator?

[Portent 0]

Only if the stat is faulty. I'd it's working correctly then it will close and keep the engine temp in the normal range.

[Hofmiester 10]

Sounds like the same fault as I had, car takes a while to warm up and in traffic gets up to temp but on a run, sits just around 70. Way to tell if the stat is stuck open is the top rad pipe will start to get warm even when the engine hasn't warmed up. The thermostat is supped to keep the water in a closed loop around the engine and out of the radiator to help warming and then release to the rad once warm.

 

Factor in changing your thermostat housing and other plastic pipes while in there as they get very brittle with age. You can get the lot from AVS for about £60, labour cost me £80 as I couldn't be arsed to do myself ;)

[Portent 0]

I need to change mine so plan on doing it in a few weeks when I do a coolant change. Thanks for the heads up on the housing (think most of my pipes have been replaced in the last few years).

 

AVS? Do you have a link? Thanks.

[Hofmiester 10]

Sure http://www.vwspares.co.uk/

[Portent 0]

Thanks.