Hi,
had a bit of a problem recently, and that is my heater in the car is literally only blowing cold air ?.
Citroen Zx Td 1993
The centre consule sometimes gets slightly hotter if the car is only idling, but i think that is the heat of the Engine. The outer vents are always cold.
I have had the Car Radiator Flushed, and an Engine Flushed, replaced the thermosatat, and had the System Bled. The car is also not overheating in anyway or form, (also Head Gasket Changed ) I cant really think of anything else that can be wrong other than the Matrix *could be Blocked*
There is not leaks from the Matrix inside the car also.
Would there be anypoint in removing the pipes from the Bulkhead and trying to flush any Gunk Out from the matrix. Could this be the Problem,
Not being a qualified mechanic
Honestly , i really am clutching at straws here.
Could anyone please put me right, or should the matrix just be replaced.
I am trying to think of any other tests that could be performed before a new matrix may be required/ fitted
Best regards
Thomas
[:)]
Anything Else i can do B4 changing Matrix
Moderator: RichardW
Are your flaps still connected to your knob? (oooerr missus)
The ZX heater works by mixing hot and cold air. If your cables have dropped off at either end, you may be stuck on cold. Does operating the hot/cold dial feel as it its actually moving something?
If that's not the problem, flushing the matrix is worthwhile. It may spring a leak afterwards, but you'd have had to change it anyway, so you're no worse off.
Finally, are you sure it's been bled properly? Check the archives for how to do it.
The ZX heater works by mixing hot and cold air. If your cables have dropped off at either end, you may be stuck on cold. Does operating the hot/cold dial feel as it its actually moving something?
If that's not the problem, flushing the matrix is worthwhile. It may spring a leak afterwards, but you'd have had to change it anyway, so you're no worse off.
Finally, are you sure it's been bled properly? Check the archives for how to do it.
There are a few reasons it may be happening, but the blocked matrix is the first to investigate.
Firstly be sure the valve that lets the water through is in the open position. (Feel like a bourke if after all the work you discover the supply has been manually turned off) Figure out which way the coolant is supposed to flow through the matrix & disconnect <b>both</b> hoses. Put a hose (either air or water) into the outlet end & back flush & see what happens. If nothing comes through, try the normal flow direction. Often, a blockage occurs just where the hose enters the matrix particularly if there's a bend there. <i><b>Carefilly</b></i> put a crochet hook (plastic) in there to locate the blockage; a crochet hook has a blunt end but does have a 'hook' attached, and work it in a circular manner. After each couple of movements, try to back flush/directional flush several times & go back with the crochet hook. Eventually a yellowy muddy looking grit will start to slowly come out & then as it soflens & without warning there will be a sudden movement & the lot will come spilling out whilst it is being pushed by the hose pressure. It usually comes out looking like something you'd expect to fall out of a babies nappy.
I have also found that liquid detergent left in the hoses (whilst disconnected & subsequently blanked off for this purpose) overnight, will also tend to soften the muck.
Be sure to rinse it out well on competion though.
Alan S
Firstly be sure the valve that lets the water through is in the open position. (Feel like a bourke if after all the work you discover the supply has been manually turned off) Figure out which way the coolant is supposed to flow through the matrix & disconnect <b>both</b> hoses. Put a hose (either air or water) into the outlet end & back flush & see what happens. If nothing comes through, try the normal flow direction. Often, a blockage occurs just where the hose enters the matrix particularly if there's a bend there. <i><b>Carefilly</b></i> put a crochet hook (plastic) in there to locate the blockage; a crochet hook has a blunt end but does have a 'hook' attached, and work it in a circular manner. After each couple of movements, try to back flush/directional flush several times & go back with the crochet hook. Eventually a yellowy muddy looking grit will start to slowly come out & then as it soflens & without warning there will be a sudden movement & the lot will come spilling out whilst it is being pushed by the hose pressure. It usually comes out looking like something you'd expect to fall out of a babies nappy.
I have also found that liquid detergent left in the hoses (whilst disconnected & subsequently blanked off for this purpose) overnight, will also tend to soften the muck.
Be sure to rinse it out well on competion though.
Alan S
Thomas,
It is very rare for a ZX matrix to be so badly blocked there is no warmth at all to the air. This would be a clue that arry B is right and that it is the air blending/heat flap or linkage not operating.
I've just done a Mondeo with exactly the same symptoms and it was a broken cable where it joined the rotary heat control.
It is easy to test for coolant flow through the matrix. Start the car from cold and hold both heater hoses at the bulkhead. You should feel one get hot first followed by the other. After a few minutes they should both be as hot (very) as the rest of the engine. If there is a serious matrix blockage you will see this won't happen as I describe.
In that case taking off the hoses and flushing the matrix in-situ will be the only hope. Take great care though because domestic mains presure, and any air line, will easily exceed that of the cooling system and blow the matrix.
Do the hose heat test first and come back to us.
David
It is very rare for a ZX matrix to be so badly blocked there is no warmth at all to the air. This would be a clue that arry B is right and that it is the air blending/heat flap or linkage not operating.
I've just done a Mondeo with exactly the same symptoms and it was a broken cable where it joined the rotary heat control.
It is easy to test for coolant flow through the matrix. Start the car from cold and hold both heater hoses at the bulkhead. You should feel one get hot first followed by the other. After a few minutes they should both be as hot (very) as the rest of the engine. If there is a serious matrix blockage you will see this won't happen as I describe.
In that case taking off the hoses and flushing the matrix in-situ will be the only hope. Take great care though because domestic mains presure, and any air line, will easily exceed that of the cooling system and blow the matrix.
Do the hose heat test first and come back to us.
David
Normal operating pressure is 14.5 psi and I have blown compressed air set at 110 psi through one but the blockage did let go before the maximum pressure was reached.
I wouldn't advise doing what I did unless you don't care if the matrix blows completely which in my case it or I didn't.
I don't know if the test pressure is available but usually these things are tested in multiples of their normal operating pressure for obvious reasons.
Alan S
I wouldn't advise doing what I did unless you don't care if the matrix blows completely which in my case it or I didn't.
I don't know if the test pressure is available but usually these things are tested in multiples of their normal operating pressure for obvious reasons.
Alan S