Are my thermostat flaps open or closed?
Posted: 26 Aug 2026, 16:00
I have a VW T25 air cooled with 2 litre CU engine
I don’t think the thermostat is working and I had read that when it fails it does so in a safe position - presumably with the flaps open so the engine does not overheat.
I don’t seem to be able to attach a pic but I hope this description suffices.
The cable from the thermostat is intact where it enters the engine bay and is secured by a pinch bolt on a rocker arm.
The cable is slack and I can push the rocker arm forward towards the front of the van which I think from the movement of the bar connecting the two metal flaps is opening them but I can’t really confirm that because I can’t see them.
So it looks like if the thermostat isn’t working. It doesn’t pull on the cable and therefore the flaps don’t open and they are in the closed position.
I hope that makes sense.
Have I got this right?
I don’t think the thermostat is working and I had read that when it fails it does so in a safe position - presumably with the flaps open so the engine does not overheat.
I don’t seem to be able to attach a pic but I hope this description suffices.
The cable from the thermostat is intact where it enters the engine bay and is secured by a pinch bolt on a rocker arm.
The cable is slack and I can push the rocker arm forward towards the front of the van which I think from the movement of the bar connecting the two metal flaps is opening them but I can’t really confirm that because I can’t see them.
So it looks like if the thermostat isn’t working. It doesn’t pull on the cable and therefore the flaps don’t open and they are in the closed position.
I hope that makes sense.
Have I got this right?
