Coolant thermostat

[Smeeagain]

thanks - who do i know if I have one of the split expansion tanks?

Smee

[jason1872]

You'll lose water and get a low coolant level warning,the part number4 is for cooling autobox

[Alan Gunn]

Smee
Did you get a replacement stat yet.
I went on a 250 mile round trip yesterday and the temp sat at 90 all day.(don't mean to rub salt and all that)...
This is the one i got but out of stock where i bought it from.
https://www.buycarparts.co.uk/mahle-original/8038870

[Smeeagain]

Yes I did. Im on my fourt dtat. No difference.
Smee

[Smeeagain]

[quote="Smeeagain"]
thanks - who do i know if I have one of the split expansion tanks?

Smee
[/quote]

Sorry we're talking at cross purposes, i thought you meant that was a type of expansion tank.
Smee

[snrbrtsn]

[quote="Smeeagain"]
Yes I did. Im on my fourt dtat. No difference.
Smee
[/quote]

A fifth, sixth or seventh stat will make no difference, ref post #89 watch the video of post 92 and change your transmission oil cooler.

[Smeeagain]

I will when someone can tell me how transmission oil cooling impacts engine water temp. The water temp at top and bottom of the rad has been measured and is low. And the stats were also proven to be defective and either stuck open/closed or not opening at the correct temperature.

[snrbrtsn]

It provides an open circuit bypass from the main thermostat, water shall take the pass of least resistance,
A back pressure has to be present in the circuit to allow heat transfer from combustion chamber to fluid jacket, the thermostats provide this back pressure allows fluid heat up, very seldom do they stay fully open though the failsafe is failopen, they oscillate between open and partially closed to maintain temperatures!

M - main thermostat
E - transmission thermostat



Your exact requirements will be one of two designs, “item no 4” or the inbuilt transmission cooler thermostat, a search on realoem will determine or discuss with Ed @ Cotswold and have him look up fitment!

Back in day, I’ve had countless discussions on thermostats, always settling on buying stats from Main dealer only, thereafter change the trans cooler stat and always cured!
Initially the main thermostat fails, giving all the work to the trans thermostat until that fails, immediate suggestions are always the same, changed the Main  thermostat with random 5hit, didn’t help, so changed to dealer, stilll didn’t help so sold the car, someone else’s problem.... etc etc.
I’d almost stand on my own testicle if the trans thermostat didn’t cure your low running temps, (probably wouldn’t go as far as posting on social media for fear of retribution haha)