rover 75 tourer 1.8T

[T-Cut]

Originally Posted by spencer burrows

when coldish i bleed the system by taking top off header tank and revving and observe speed of coolant. is this okay to do?

There's no problem in doing this with the engine cool, but there should be no movement of coolant to assess the pumping speed. It might rise and fall a little with the revs, but there's no visible flow across the tank. The header isn't part of the coolant circuit and stands atop a single pipe tee'd into the lower radiator hose. It doesn't have coolant circulating in/out or across it. Any gurgling from the header is simply air rising up the header pipe as you circulate it with the pump. It not the correct method.

In the 1.8 I've never observed the flow of any coolant from the head vent which enters the neck of the header tank, nor the invisible co-vent hole that's hidden from view. This is so even when revving hard. However, a few owners of the V6 report significant flows from here when revving. They see two streams. Notwithstanding, the small bore pipes involved are for venting air from the head/heads and not for coolant circulation.

I have to top up when it throws out the coolant. defo see coolant bubbling out of header cap only after higher revs. then i have to top up. i is not huge amounts and i am not over filling as the line is clear to see in the bottom of header tank.

I assume you mean with the cap off? In any case, it's not the correct way to bleed/top up. You should follow the method described in Haynes and repeatedly on the forum.

If revving the cool engine causes coolant to be ejected when the cap's screwed down it is not a good omen IMO. Something is creating a coolant pressure exceeding 22psi and the pump can't do that.

TC