Possible thermostat issue...

[Speedwell68]

...or maybe something else.

Hi. I have recently bought a 1990 Autohomes Kamper MK4 T25. It has a stock 1.9 DG engine. It goes pretty well. I have owned two Aircooled T25s and a 1968 Bay, so most of my tinkering experience has been Aircooled. The engine gets hot, but the temp gauge needle never seems to get much above the white section of the gauge. I do have some experience of VW watercooleds in the form of Mk2 Sciroccos and 5 cylinder Passats. This has the same gauge, one of my Sciroccos had a similar fault which turned out to be a thermostat that failed in the open position. My gut feeling is that I have the same fault here. Is there anything I should be checking?

It has a full service history, but not all of it has been done by a VAG garage and I can't tell when the coolant was l;ast changed. So it was my intention to lay the van up over winter and go through the list of jobs I have identified, give it a full service and change the coolant for genuine VW G12 antifreeze.

[itchyfeet]

easy to check if the thermostat works
start it up and let it idle, feel the large pipe that enters the thermostat housing at the top from the front of van, it should be cold ( this is the return from radiator) as it heats up this should stay cold until the thermostat opens when it gets hot quite rapidly, perhaps 15 to 20 mins at idle.

[Speedwell68]

easy to check if the thermostat works
start it up and let it idle, feel the large pipe that enters the thermostat housing at the top from the front of van, it should be cold ( this is the return from radiator) as it heats up this should stay cold until the thermostat opens when it gets hot quite rapidly, perhaps 15 to 20 mins at idle.

Awesome. I will give that a go.

Thanks.

[Oldiebut goodie]

The previous owner has possibly removed the thermostat - people do strange things like that for some reason.

[Speedwell68]

The previous owner has possibly removed the thermostat - people do strange things like that for some reason.

People do that on Aircooled engines too, generally on the basis that VW had no clue about what they were doing, but some beardy idiot down the pub does. On a Scirocco the thermostat housing would not seal without the stat being in place. Is there a way of testing for a missing stat too?

Again thanks for the replies.