17 replies to this topic

[Big Man]

1992 Spi Cooper:

I have changed the thermostat, with a new one with drilled holes (5 - 5mm) engine runs fine with no coolant loss whatsoever however I can not seem to get any heat through the heater. I have checked the pipes that lead from the Stat to the heater valve and there is no water passing through the open heater valve. I checked this by undoing the exit pipe from the heater valve and running the engine. The pipe that lealeads from the thermostat has a T and gets nice and hot but after the heater valve stone cold!!! Heater valve works fine and is OPEN so water should circulate but its NOT!!!

Does this means that my system is not pressurised?

Could it be the water pump not pumping the water around the system? Fan has no play and no horrible noises etc.

I bled the system for a good half hour with heater on and gave the pipes a good squeeze.

Any ideas would be most welcome!!!


Like I said car runs fine - no coolant loss etc just no warm pipes so to speak!!!

[taffy1967]

There could be an air-lock in the system, so take the radiator cap off (whilst engine is cold), again make sure the heater tap is open (pulled out) and start the car. Let it idle and warm up until the coolant starts to bubble up slightly and then replace the radiator cap.

Hopefully this will clear any air-locks.

[Big Man]

There could be an air-lock in the system, so take the radiator cap off (whilst engine is cold), again make sure the heater tap is open (pulled out) and start the car. Let it idle and warm up until the coolant starts to bubble up slightly and then replace the radiator cap.

Hopefully this will clear any air-locks.

Hi taffy,

I have done this but to no avail, first time with new thermostat (not drilled) then second time when I had drilled thermostat and put it all back together. Just seems really strange that with the pipe off the heater valve and the valve open no water is circulating through?

BM

[taffy1967]

Have you driven the car since fitting the new thermostat? I'm no expert but I'd imagine it would overheat if the water pump had gone?

[Sprocket]

Is the thermostat in the top of the sandwich plate, rather than below it?

[Big Man]

Driven the car - no overheating.

Thermostat above the sandwich plate not direct into the block.


Still stumped?

Cheers

BM

[Big Man]

Any Ideas anyone???

Cheers

BM

[taffy1967]

Are you sure the heater tap valve is opening when you pull the cable?

I remember a mate from my old Mini Club was having problems with his Cooper 1.3i and it turned out that a previous owner had refitted the control valve upside down. Okay having it the right way up helped the cable operate properly and then he got full heat.

Apart from that you don't need to have holes drilled into your thermostat.

[Big Man]

Are you sure the heater tap valve is opening when you pull the cable?

I remember a mate from my old Mini Club was having problems with his Cooper 1.3i and it turned out that a previous owner had refitted the control valve upside down. Okay having it the right way up helped the cable operate properly and then he got full heat.

Apart from that you don't need to have holes drilled into your thermostat.

Def open and tried it when had it removed form the pipe work, stat is drilled to see if any water was coming through and nothing coming through at the heater valve?

Cheers

BM

[taffy1967]

Well this is how the pipes look on my Mainstream Mini Cooper: -

[taffy1967]

Here's a better shot (of my mates Cooper): -

[coopertrooper2001]

Sounds like an air lock.

Take the heater hose off and put a hose pipe in and turn the water on (not too hard) until water comes out the other end - this should push the air out.

[taffy1967]

Yes and any silt which has built up in the matrix too.

[Big Man]

Hope fully will get some time at work to give it a go tonight................however my question still is why is there no water going through the pipe from the stat to heater valve? surely if its an air lock removing the heater control valve leaving the pipes unconnected engine running would pump water through..........it doesn't!

BM

[Big Man]

Everything flushed through reassembled and works perfect............... thanks all

Cheers

BM