19 replies to this topic

[karl & his cooper]

Best way to think of it is that the pump draws water in through the bottom hose and pushes it in to the engine. The engine heats the water so the heater should go between the engine (cylinder head) and bottom hose. The thermostat restricts flow through the radiator until the engine is up to optimum temperature, if you want a heater to demist 'n defrost windows then the heater needs to be on the engine side of the thermostat or it won't get hot until the radiator does.

so I am going to have to put a few holes in my thermostate?
I was told by people on here that id I drilled out the missing heater outlet on the metro 1275 head then it will all be fine, its connected up how my 998cc was and that never overheated and was allways had hot air when I needed it?

[Ethel]

Yes, fitting the heater tap to the driver's side of the head is fine for sorting your heater, but you still need some sort of bypass (holes or hose) to get the water to circulate around the 'stat - if you don't the engine is liable to overheat before the 'stat opens.

[karl & his cooper]

Yes, fitting the heater tap to the driver's side of the head is fine for sorting your heater, but you still need some sort of bypass (holes or hose) to get the water to circulate around the 'stat - if you don't the engine is liable to overheat before the 'stat opens.

how many holes of what diameter?

[Ethel]

I'd try three or four 5mm holes (in the disc bit), you can always add more if needed

[Tinkerbelle]

Maybe we can learn something here about checking the odvious.

I checked it all out at the weekend and all components were fine, but I did remember cutting the end off of the heater control cable once. Which upon checking has made it too short so not allowing the valve to open sufficiently and the flow was too low to notice.

New cable = open valve and lovely heat.

Thanks for help and advice.

Matt