Hello All,
Having seemingly been successful in sealing up the head gasket...at least for now anyway! I am considering replacing the heater matrix.
Before I go any further though is there a simple test I could perfrom to check if the Matrix is clogged up? ie simply open up the bleem valve on the 'return' tube at the bulkhead of the Engine / Dash?
Having flushed it many times etc, I know that water comes out of here and would have thought that where there's water there should be heat....but very little heat is coming into the car!
All help greatfully received
Rod
Heater Matrix replacement
Moderator: Moderators
Re: Heater Matrix replacement
You sealed up the head gasket? How did you do that? Did you fit some sort of sealant? If so, this could have blocked up the heater matrix.
Take off the heater outlet pipe and run the engine, if water floods out of here then the matrix should be ok.
Have you replaced the thermostat? Does the car radiator get hot all over or is it cool in places? Have you actually bled the heater and the whole system?
I wouldn't attempt to replace the heater matrix until you are 100% certain that it is blocked....it's a massive job.
Take off the heater outlet pipe and run the engine, if water floods out of here then the matrix should be ok.
Have you replaced the thermostat? Does the car radiator get hot all over or is it cool in places? Have you actually bled the heater and the whole system?
I wouldn't attempt to replace the heater matrix until you are 100% certain that it is blocked....it's a massive job.
Re: Heater Matrix replacement
Hello, thanks for the reply
Its a long story but basically, I suspected that the heater matrix was blocked some time ago but did'nt realise that i could bleed it etc until I was told that I may have a HG problem as we found an oil/water mix on the dipstick. Also found that I had a small leak in the radiator.
So, drained the complete system, flushed it many times and added 'block seal' which was recommended by an engineering company that we know. It is the 'best' one you can get to do a HG and not a cheapie. Followed the instructions to the letter and three weks later have checked the oil and water and there is no oil/water mix evident and i'm not loosing any water. I can only assume that the seal is working for now!
My atention is back on the matrix as there is almost no heat coming into the car.
If I bleed the return from the matrix I get water coming out and the pipe is warm, so i thought that this is normal ?...very hot water going into the matrix and cooler water coming back out?
I haven't checked the pump or the radiator for cold spots though.
Its a long story but basically, I suspected that the heater matrix was blocked some time ago but did'nt realise that i could bleed it etc until I was told that I may have a HG problem as we found an oil/water mix on the dipstick. Also found that I had a small leak in the radiator.
So, drained the complete system, flushed it many times and added 'block seal' which was recommended by an engineering company that we know. It is the 'best' one you can get to do a HG and not a cheapie. Followed the instructions to the letter and three weks later have checked the oil and water and there is no oil/water mix evident and i'm not loosing any water. I can only assume that the seal is working for now!
My atention is back on the matrix as there is almost no heat coming into the car.
If I bleed the return from the matrix I get water coming out and the pipe is warm, so i thought that this is normal ?...very hot water going into the matrix and cooler water coming back out?
I haven't checked the pump or the radiator for cold spots though.
Re: Heater Matrix replacement
Hello again,
Sorry just realised that I hadn't read your post correctly....
The heater ws not working before I added the seal, and when I did add the seal I clamped off the flow / return to the matrix, so no sealant could get in.
I haven't checked the thermostat, is it 'top right' on the block in the domed housing?
Sorry just realised that I hadn't read your post correctly....
The heater ws not working before I added the seal, and when I did add the seal I clamped off the flow / return to the matrix, so no sealant could get in.
I haven't checked the thermostat, is it 'top right' on the block in the domed housing?
Re: Heater Matrix replacement
Hello Rodders, not sure which engine you have for thermostat location, but sounds about right.
If you have hot water going in and hot water flowing out then there must be a problem with the heater flaps not sending hot air into the car.If you have hot water going in and cool water coming out, i'm afraid that doesn't make sense, you should have hot water going in and coming out, if the matrix was blocked you wouldn't have any water coming out or at least not much.
If I was asked to check this out, firstly I would replace the thermostat, then fill up the system by putting water into the tank with the bleed screw on the radiator open until water floods out consistantly,(should be located on top of the radiator, usually a round plastic screw) then run the engine up to temperature with the small plastic bleed screws undone until hot water floods out of them, it would help to have the front of the car higher than the back, ie, pointing uphill, some people like to use a bottle fitted into the tank and full of water to help bleeding, I don't use that method.
If you can't get water flooding out of the heater at speed, then maybe you have a broken water pump.
If you have hot water going in and hot water flowing out then there must be a problem with the heater flaps not sending hot air into the car.If you have hot water going in and cool water coming out, i'm afraid that doesn't make sense, you should have hot water going in and coming out, if the matrix was blocked you wouldn't have any water coming out or at least not much.
If I was asked to check this out, firstly I would replace the thermostat, then fill up the system by putting water into the tank with the bleed screw on the radiator open until water floods out consistantly,(should be located on top of the radiator, usually a round plastic screw) then run the engine up to temperature with the small plastic bleed screws undone until hot water floods out of them, it would help to have the front of the car higher than the back, ie, pointing uphill, some people like to use a bottle fitted into the tank and full of water to help bleeding, I don't use that method.
If you can't get water flooding out of the heater at speed, then maybe you have a broken water pump.
Re: Heater Matrix replacement
Hello
If what you say is accurate and you have little or no heat through the matrix then you may have a typical blockage in a number of the small channels that form the exchanger matrix. This is quite common in radiator and heater matrix when sludge forms in the very centre of the matrix and blocks enough to cause a serious loss of flow. The big problem is that many channels will still be clear and allows enough hot water to pass around the edge channels to fool you into thinking it's clear when it's lacking high flow rate to circulate heat though the matrix centre by the blower. Sadly back flushing will not always work since you cannot get enough back pressure to shift it because water will take the easiest path ie around the few that are free. The only way I have overcome this is to remove the matrix from under the passenger side glove box and gently massage it with a propane torch and keep filling and emptying it until you see all the brown sludge run clear and you can feel that heat is getting down all the channels - at this stage most garages would have binned it and fitted a new one but if you are patient and you clear it you will feel clever. Of course check that all the flaps are working and that your A/C is not chilling the air through a malfunction before taking the matrix out.
Good luck and let us know how you go on.
If what you say is accurate and you have little or no heat through the matrix then you may have a typical blockage in a number of the small channels that form the exchanger matrix. This is quite common in radiator and heater matrix when sludge forms in the very centre of the matrix and blocks enough to cause a serious loss of flow. The big problem is that many channels will still be clear and allows enough hot water to pass around the edge channels to fool you into thinking it's clear when it's lacking high flow rate to circulate heat though the matrix centre by the blower. Sadly back flushing will not always work since you cannot get enough back pressure to shift it because water will take the easiest path ie around the few that are free. The only way I have overcome this is to remove the matrix from under the passenger side glove box and gently massage it with a propane torch and keep filling and emptying it until you see all the brown sludge run clear and you can feel that heat is getting down all the channels - at this stage most garages would have binned it and fitted a new one but if you are patient and you clear it you will feel clever. Of course check that all the flaps are working and that your A/C is not chilling the air through a malfunction before taking the matrix out.
Good luck and let us know how you go on.