Well b#gger me!
We replaced the valve. No improvement.
Was suggested to replace the engine coolant temp sensor for the sake of £16 and 10 minutes time. No improvement! (top tip - but the little plastic circlip at the same time as the senor. Its £2 well spent!!)
Is the irony here that I am now looking at the thermostat (the route that I went with the 3.0 before finding out about the little valve under the gearbox
)
The symptoms are that the car is very slow to warm up. The gauge remains on 50 for a good 10 minutes (+). It will eventually creep up to 70. If out on a longer run of 30 mins or so with a bit of traffic it will sit just below 90.
Interestingly, even when just over 50 I can still get enough heat into the cabin to at least take the chill off. And at 70 it will happily warm the cabin.
Any thoughts welcomed
