Muppet question re Coolant flow
 

I feel like a twit asking this but...

On every car I've known the coolant flows into the top of the radiator gets cooled then exits at the bottom.

I've just flushed my heater matrix - I'm traditional like that - and was checking for airlocks afterwards when I decided the top hose, although hot, didn't feel full of water. So, I undid the top joint and yep, empty. So, engine running, added more to the tank expecting it to fill the pipe but instead it started flowing out of the radiator.

Seems logical to me then that either the thermostat isn't allowing water into the top hose or the pump operates in the other direction....

Could someone advise?

ps. the good news is that the heater is not hot both sides.

Ignore me.
Just found this diagram for the V6:
https://www.the75andztclub.co.uk/for...4&d=1542914247
Seems the coolant should go round the normal way :¬)
I hadn't realised the thermostat was on the return side. Guess I'm still a newbie...

Just dashed out & checked the pipes are on the right way round so thats good. Which leaves the question as to why I'm not getting coolant flowing along the top hose.

Any thoughts?

Peter, I'd suggest draining, refilling and bleeding using the official MG Rover procedure which, if followed precisely, will eliminate any air locks.

Simon

Hi Simon

That's essentially what I did a while ago when I replaced the radiator. I was just a bit surprised that after undoing the top hose at the radiator water was flowing out of the rad but nothing from the hose. I was obviously barking up the wrong tree with the thermostat but logically I'm now thinking that perhaps as I lifted the hose up an inch or two it was easier for the water to flow back that way even against the flow of the pump.

Hi Peter,

Undoing the top hose is not a recognised service procedure! Also, I'm not convinced that the top hose is ever full of coolant.

So apart from your curiosity, is there anything wrong with your cooling system? :D

Simon

From what you've said it would seem your heater matrix is half blocked and you have air in the cooling system because you didn't follow the procedure correctly.---:shrug:---Maybe.--;)

The heater is fine - I was doing this work after flushing it through.
And seems no other problem with the cooling - warms up nicely and everything seems good as far as I can test sat on the drive using an ODB app. Hopefully I'll have an excuse for a necessary journey at the weekend to give it a proper test.

I was just a bit perplexed by the apparent lack of flow but perhaps thats normal. Would be lovely if the thermostat was as easy to get at as it is on an a-series engine :¬)