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Coolant-system-bleeding a 'K' Series Rover 45...

14K views 4 replies 5 participants last post by  simong1 
#1 ·
Hello everyone.

Just want a bit of help really on my mum's car...

Basically the heating hasn't really been right since she's had it (had it about 6 months now). The car's heating switch would only work on settings 3 & 4; worked this out to be the resistor pack and i've ordered the open coil resistors off Rezpax on ebay. Anyway back to the reason why i'm here...

The car's heating only works when driving about. When the car is stationary, the heating is freezing. Simple words. The car does not overheat as far as I am aware, thinking this may be an airlock of some sort, or worst case scenario a blockage.

The engine is passing coolant through fine, all pipes getting hot as they should, apart from the bottom hose on the radiator. Now I know this is suppose to be 'colder' than the top one due to it beeing cooled down through the radiator, but it's not even got a temperature on it. Feels like the car hasn't been started all day.

So last night, gave a few pipes a bit of a squeeze (without undo-ing any bleed screws etc) and now the heating is permanently cold. Not a head gasket problem, no white/blue or black smoke, and no oil in water/water in oil etc.

It's making me think whether it may be the thermostat stuck, or a clogged radiator, but i'm more of a Fiesta guy with all this and not used to the Rover procedure.

It would be of GREAT help if somebody could tell me how to bleed whichever relevant system for the heating etc. I know there is a bleed screw on the coolant rail between the engine and airbox, seen this last night.

Also it would be great if someone could explain the best procedure for cleaning the radiator out at an attempt if you think it is this.

Thanks muchly in advance :)
 
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#2 ·
sounds like airlock,and squeezing hoses will force this around, running from cold with expansion cap off and squeezing hoses,may help also.when the system is hot,feel the radiator all over,for cold areas,and again squeeze bottom hose to force any lock around.if you intend starting from scratch,draining system,and then reverse flush the rad,hosepipe in bottom and force water up to top,do same to the heater matrix,flushing both ways.i usually take rad out,very couple of years,and leave filled with coke,for a day or two,will shift silt from bottom.
 
#3 ·
Hello everyone.

Just want a bit of help really on my mum's car...

Basically the heating hasn't really been right since she's had it (had it about 6 months now). The car's heating switch would only work on settings 3 & 4; worked this out to be the resistor pack and i've ordered the open coil resistors off Rezpax on ebay. Anyway back to the reason why i'm here...

The car's heating only works when driving about. When the car is stationary, the heating is freezing. Simple words. The car does not overheat as far as I am aware, thinking this may be an airlock of some sort, or worst case scenario a blockage.

The engine is passing coolant through fine, all pipes getting hot as they should, apart from the bottom hose on the radiator. Now I know this is suppose to be 'colder' than the top one due to it beeing cooled down through the radiator, but it's not even got a temperature on it. Feels like the car hasn't been started all day.

So last night, gave a few pipes a bit of a squeeze (without undo-ing any bleed screws etc) and now the heating is permanently cold. Not a head gasket problem, no white/blue or black smoke, and no oil in water/water in oil etc.

It's making me think whether it may be the thermostat stuck, or a clogged radiator, but i'm more of a Fiesta guy with all this and not used to the Rover procedure.

It would be of GREAT help if somebody could tell me how to bleed whichever relevant system for the heating etc. I know there is a bleed screw on the coolant rail between the engine and airbox, seen this last night.

Also it would be great if someone could explain the best procedure for cleaning the radiator out at an attempt if you think it is this.

Thanks muchly in advance :)
look here:http://forums.mg-rover.org/showthread.php?t=443844:xmastree:
 
#4 · (Edited)
First of all, a blockage in the main radiator WOULD NOT stop the cabin heater working, so forget that. What it might do is cause the car to overheat (depending on just how blocked it was).

I have never studied the cooling system, however, the cabin-heater and radiator must operate on parallel circuits. I don't subscribe to theories about airlocks (quite simply, air does not block pipes) however, where you have two parallel paths, water will tend to take the easiest path, therefore, to clear the blockage (or airlock) you must increase the resistance in the easy path. The only way you can do that is by clamping one of the radiator pipes (the top one will be easier). If the water is unable to circulate around the radiator circuit it will be forced to circulate around the cabin-heater circuit.

I recommend you get the car fully warmed up, switch off, apply the clamp, run it at speed (maybe 2000 -3000 rpm) for 20 seconds with the heater on maximum and then switch off. Alternatively, you could tighten the clamp with the car running, but there are obvious risks to that.

I'm not sure what you should use to clamp the hose, I would try a big G-clamp (just ensure you don't damage it).
 
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