24 replies to this topic

[benb12]

Model: Cooper SPi
Year: 1994
Description of problem (please be as in depth as possible):

My heater is severely lacking heat. It takes ages to blow anything vaguely warm, and when it does it only does it for about 30 seconds. The pipes to and from the matrix and the matrix itself are not blocked as I have blown through it with ease. I have run a cooling system flush through the system, removed all hoses to check for blockages, reversed flushed the rad, replaced thermostat (88 degrees) and the problem hasn't been solved. The only other things I can think of is that the heater is somehow plumbed into the thermostat controlled part of the system or that the water pump isn't efficient enough (which seems unlikely as there's no nasty noises and the temperature sits bang on the middle line).

Does anyone else know what it could be?

[Boycie]

Hi mate, are both hoses going to the matrix hot?

[R1minimagic]

Check the heater hot/cold valve under the bonnet, could be stuck closed or gunked up!

[bmcecosse]

Does sound like closed valve - try taking it out and just using a stub of pipe! Or wrongly piped hoses - are they short circuited in some way? Highly unlikely to be the water pump if the engine temperature is ok.

Edited by bmcecosse, 11 February 2010 - 09:27 PM.

[benb12]

Boycie, I haven't actually felt them after a drive, I'll do it tomorrow.

R1, took that off, I thought it was the problem at first because I knew it was stuck - when I took it off turned out it was stuck open!

[benb12]

Does sound like closed valve - try taking it out and just using a stub of pipe! Or wrongly piped hoses - are they short circuited in some way? Highly unlikely to be the water pump if the engine temperature is ok.

As above, I know the valve is open. I did think wrongly piped hoses as it really indicates that it's being controlled by the stat, however I can't see how it can be plumbed in wrong.

[tadleysimon]

you said you blew through it with ease?
its 100% a air lock. take the rad cap off. take off one of the heater pipes under the bonnet. attach your garden hosepipe and SLOWLY let water through. this will push the air out of the matrix and fill it with water, the air should bubble out of the rad.

[Boycie]

Get a piccy up mate. But I suspect, if both hoses have heat, the matrix requires replacement.

[tadleysimon]

Get a piccy up mate. But I suspect, if both hoses have heat, the matrix requires replacement.

he didnt say both have heat, and id bet that one does and one doesnt, hence the 30 secs of warmth. id bet my last pound on it being an air lock

[benb12]

you said you blew through it with ease?
its 100% a air lock. take the rad cap off. take off one of the heater pipes under the bonnet. attach your garden hosepipe and SLOWLY let water through. this will push the air out of the matrix and fill it with water, the air should bubble out of the rad.

I suppose that's the next thing to try. When I said blow through it with ease, what I meant is I disconnected a pipe from the matrix and blew through it, and without much effort I heard bubbles go around the system and come back up the radiator. Unfortunately I don't have a hosepipe, will see if I can borrow one.

[tadleysimon]

you said you blew through it with ease?
its 100% a air lock. take the rad cap off. take off one of the heater pipes under the bonnet. attach your garden hosepipe and SLOWLY let water through. this will push the air out of the matrix and fill it with water, the air should bubble out of the rad.

I suppose that's the next thing to try. When I said blow through it with ease, what I meant is I disconnected a pipe from the matrix and blew through it, and without much effort I heard bubbles go around the system and come back up the radiator. Unfortunately I don't have a hosepipe, will see if I can borrow one.

exactly, you heard bubbles because you forced air through the system, so the pipes are full of air, push water through and the air will come out. if you dont have a hose pipe then stick a funnel on the pipe and pour water in. youll need to hold the funnel higher than the system for it to circulate

[benb12]

you said you blew through it with ease?
its 100% a air lock. take the rad cap off. take off one of the heater pipes under the bonnet. attach your garden hosepipe and SLOWLY let water through. this will push the air out of the matrix and fill it with water, the air should bubble out of the rad.

I suppose that's the next thing to try. When I said blow through it with ease, what I meant is I disconnected a pipe from the matrix and blew through it, and without much effort I heard bubbles go around the system and come back up the radiator. Unfortunately I don't have a hosepipe, will see if I can borrow one.

exactly, you heard bubbles because you forced air through the system, so the pipes are full of air, push water through and the air will come out. if you dont have a hose pipe then stick a funnel on the pipe and pour water in. youll need to hold the funnel higher than the system for it to circulate

Cheers Simon, I will definitely try it. I have to point out though that the reason I blew through it in the first place was because of the lack of heat - I guess it is possible that there was an airlock before I tried it.

[tadleysimon]

yer probaly, the fact that you have removed all the hoses ect suggests an air lock. ive had the exact same thing as you have described (a little warm air for about 10-20 seconds then cold air.) about 4 times after playing with the cooling system.

been an air lock every time.

Edited by tadleysimon, 11 February 2010 - 09:44 PM.

[benb12]

Cheers mate, I'll do it before I set off tomorrow morning - can only take a couple of minutes with a screwdriver, funnel and bottle of water. If it doesn't fix it then I don't know what will.

Thanks for the quick responses everybody.

[tadleysimon]

ive never done it with a funnel but i dont see why it wouldnt work. you just need to get it high enough to push the air out.

i know for sure a hose pipe works perfect.

good luck