Coolant Temperature ?

[OxfordRich]

Evening..
While logging my car for faults I spotted that VCDS shows my coolant temperature to fluctuate somewhere between 77 and 81 degrees C. This surprised me as I was expecting it to return something nearer 90 degrees C, so when I got home I took my wife's 2.0T for a thrash and measured the temperature on that as well - it was even cooler sticking around 75 degrees C.

On both cars the temperature gauge rises to 90 and stays there (although mine dips by a couple of mm on the motorway) but I was partly expecting this as they're so heavily damped to prevent people from panicing.

So, can somebody confirm this is normal and a decent temperature from VCDS measurements for this time of year (it's 1 degree C ambient temperature out there when these measurements were taken) or do I have two cars with thermostat issues?

Rich

 

[ex911driver]

If they had problems with the stat or cts they normally show up when scanned , stats maybe getting lazy.

 

[OxfordRich]

Sure..

I'm good at waiting for faults to get logged before I fix things, but I'm asking what temperature people see reported with VCDS when the dash gauge shows 90.

 

[OxfordRich]

Asking and answering my own questions again.. thouht I'd resolve this for any future searchers!

Today I replaced the thermostat. The car now averages 93-95 degrees C, which is much more like it. So that's the answer to my first question, yes it was stuck open or getting slow.

It required removing alternator and a couple of other bits which were easy, the tricky part was getting the top hose off the old thermostat, took me about an hour, they're well stuck on there. I expect this will become a common issue on the forum as time passes, I find it odd that out of both the 2.0T's on my drive, both had the issue. Whole job took me 3 hours and worst part was freeing the hoses from the thermostat.

Thermostart Part number is 06D 121 111 G (or 06D121111G without spaces!) and it was £25.25

 

[Molnboman]

Yep, you answered your own question there.....I had the same issue on mine.....been right as rain ever since! Seems to be a common issue and I have read of many owners who just live with it....but I noticed my bus had an unhealthy appetite for drinking more fuel so had mine changed.

Good Luck
A

 

[OxfordRich]

Thanks

For what it's worth, we now know that the temperature display in the instrument cluster will stick to '90' for temperatures between 83 and 107 degrees, quite a range!

I'm not sure how keen I am to try this same job on a mk5 Golf GTI but i'll weigh it up i guess. The golf is drinking more fuel than the quattro with the same engine and I think this is why.