24 replies to this topic

[benb12]

I tried pouring water into the hose this morning and it went in okay, but no air came through the rad and the heater is the same. I'll try to get hold of a hosepipe in case it needs a bit of pressure to force the air out, if this doesn't work I'll have to wonder if it's plumbed in wrong. Perhaps if the two pipes going to the matrix have at some point been switched by mistake, this would cause the problem? If the water was going down the matrix instead of up? I don't know.

[tadleysimon]

its basically impossible to blum the heater in wrong, you have once pipe that goes from the heater to the bottom hose and one from the heater to the cylinder head,
i
try a hose pipe to push the water through, if not i suspect a new heater matrix might be in order,

[MiniMonty]

Sounds to me like your heater matrix has gone south.
Any moisture on the floor / carpet in the passenger footwell ?

Or maybe water pump not giving all it should (loose or oily fan belt) ?

[benb12]

Sounds to me like your heater matrix has gone south.
Any moisture on the floor / carpet in the passenger footwell ?

Or maybe water pump not giving all it should (loose or oily fan belt) ?

I'm sure the matrix itself isn't leaking. Didn't consider fan belt, mainly because the alternator seems to be charging perfectly and I've had no overheating problems - the temperature sits bang on the middle line since I replaced the stat.

[Ethel]

Doesn't the SPI have the heated manifold plumbed in as the thermostat bypass? It could a restriction in the heater means most of the flow is going through the manifold instead.

[emmaco]

I have exactly the same problem and recently had my thermostat replaced at a mini dealer - could this be the cause?

[benb12]

Picture may or may not help:



The hose you can see at the top runs from the stat to the control valve and into the bulkhead. Branching off it is a hose for the inlet manifold. The other heater hose comes out of the bulkhead and into the bottom hose - again, branching off it is a hose to the inlet manifold.

[benb12]

I have exactly the same problem and recently had my thermostat replaced at a mini dealer - could this be the cause?

I thought this and replaced it with no success on the heater front, however the engine gets up to temperature much better now!

[tadleysimon]

ok lets start again.

1. are your sure that the sandwedge plate under the thermostat isnt blocked?
2. are you 100% sure the heater valve works. (try taking it off and seeing if you can see through it)
3. with the engine up to temperature are the hoses to the heater hot or not?

lets assume everything is fine but you have one hot pipe and ove cold pipe. (normal symptons of an air lock.)

disconnect both pipes to the heater and fill with water. (funnel or hosepipe job) this will make 100% sure that the heater is full of water.

do the same with the inlet manifold pipes.

theres not many things it can be,
if water flows through the heater ok then its not blocked,
if you can see through the valve its fine
if you make sure the heater is full of water then it will circulate. if its full of air then it wont,

[benb12]

ok lets start again.

1. are your sure that the sandwedge plate under the thermostat isnt blocked?
2. are you 100% sure the heater valve works. (try taking it off and seeing if you can see through it)
3. with the engine up to temperature are the hoses to the heater hot or not?

lets assume everything is fine but you have one hot pipe and ove cold pipe. (normal symptons of an air lock.)

disconnect both pipes to the heater and fill with water. (funnel or hosepipe job) this will make 100% sure that the heater is full of water.

do the same with the inlet manifold pipes.

theres not many things it can be,
if water flows through the heater ok then its not blocked,
if you can see through the valve its fine
if you make sure the heater is full of water then it will circulate. if its full of air then it wont,

Have hooked up a hosepipe and the rad just filled up with water... no bubbles and no difference in heat.

I took it for a blast to check, and when I got back I felt the two hoses inside the car. One was hotter than the other. When I sqeezed the cooler one, it crunched quite a lot. I carried on squeezing it and took it for a spin again, it came through hot straight away but quickly cooled again. I'm now thinking that I have loosened what was scaling up the inside of the pipe and it is now blocking something up - possibly the matrix. Definitely the next thing I will do is remove the hoses inside the car and clear them.