Just fired up the truck after the head gasket job and it ran great...except it ran really hot. I followed the bleed process. I looked at the image of which way the tstat installs and the image in the rover manual shows the angle on the drivers side. I am thinking maybe that might be wrong because it got almost to the red zone after 10 minutes of idling. So, which way does the t-stat angle go?

Thanks everyone...almost back on the road

 

Angled fitting goes towards the passenger side on LHD vehicles sold in North America.

 

Perhaps this drawing from the RAVE will help. Also hope you don't have trash in the top of the stat blocking the small holes.

 

wonder which image I was lookin then??? I definitely have it installed backwards.....thanks!!

 

Yep, cooled-off coolant collected from the bottom hose of the radiator goes up the axial inlet port. Really hot coolant from the T fitting descends into the top axial port and those sampling holes. This mixes inside the chamber, and when warm enough the stat opens and sends plenty of cooled off coolant via the side arm port to the water pump. When warming up, that metering bypass disc descends and allows more rapid warm up of the heater core. When the main stat opens, a spring shoves the bypass disc back up. Here's a pix of a cutaway done by an owner.

Same sort of bypass thermostat is found in Mercedes, Fords, and other vehicles. Trash in the little metering holes slows water transfer, and makes stat open later than it should.