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Heater valve enquiry - no heating

Has the heater worked at all since the summer? It could be the matrix has become blocked with garbage. There are solutions that will clean this however they are caustic and could bring up other problems in the future, for example if you main radiator is old it might result in a leak?

regards

Dave
 
Hey Dave did use it but not much. It was working on the night i was driving to my destination and then on the return run it completely was blowing cold. Since then I’m seeing the temp on the dash a little lower than normal and the heat is mild at best but still functioning for now.
I’m leaning towards the temperature thermostat but simply haven’t had much time to get it checked out at the garage.

P.s the heater matrix was changed in 2017 and no leaks of coolant are present in the foot well.

Thanks
 
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Might be worth burping the hoses on the cooling system in case an air lock and lack of circulating coolant is causing the lack of cabin heat.

Also, the water in footwell could be a leaky windscreen seal, especially if not the original screen?
 
Yeah I’ve done my own check here and there but gonna get it check out at the garage for a better inspection next week.

The screen is original and the rubber was change to new in 2016 by a windscreen guy. Strange on another day it rained the water didn’t return so still a mystery for now.

Thanks
 
Worth checking is the water exits from the bulkhead, if they are obstructed and there is enough rain the area under the wipers where the motor sits can flood, if that happens then water will enter the car from the air intake for the heater and ventilation, this made worse if the car is parked at an angle.


Regards

Dave
 
Sorry not thinking as quick as I should, the 80 has a problem with the temperature gauge design, it is damped so as soon as the engine gets anywhere near operating temperature the gauge comes up and stops. It is is only when the engine gets very hot does it move....often too late to notice. I can only think this is something to do with the thermostat being in the bottom hose as opposed to the top? I modified the resistors in my gauge to show the real temperature the engine is running at. So your problem could be a jammed open thermostat.

Regards

Dave
 
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Update: Been many weeks and somehow the heat didn’t seem too back and seems to have got better over time but wanted to see what it could be to know better. The dash temp looked pretty normal too now.

Today visited the garage and started a deeper enquiry for fault finding. Was advised to undo both coolant entry points on the firewall to the heater matrix to see if there was blockage / buildup of crap. All looks good with a pressure garden hose flush.

Then in the cab looked at the heater climate control switches. Cold to hot slider that opens up the reverent parts in and under the dash. At this point selecting hot reverted back to blowing cold again like before for some reason.

On the diagram online looks like 4 different parts that the failure to open the heat to the cab could be.
Note: At this point he rear heater switch was turned on and hot air works towards the back ok.

Drivers side left side under the dash clearly could see the mechanism moving up and down. Also passenger side bottom under dash too looks good.

At this point a easy fix was hard to find and my cousin at the garage said he will look into which remaining two is the one that could be at fault.

Very uncommon this is but not something that fails.

Any ideas welcomed… thanks
 
Update: Been many weeks and somehow the heat didn’t seem too back and seems to have got better over time but wanted to see what it could be to know better. The dash temp looked pretty normal too now.

Today visited the garage and started a deeper enquiry for fault finding. Was advised to undo both coolant entry points on the firewall to the heater matrix to see if there was blockage / buildup of crap. All looks good with a pressure garden hose flush.

Then in the cab looked at the heater climate control switches. Cold to hot slider that opens up the reverent parts in and under the dash. At this point selecting hot reverted back to blowing cold again like before for some reason.

On the diagram online looks like 4 different parts that the failure to open the heat to the cab could be.
Note: At this point he rear heater switch was turned on and hot air works towards the back ok.

Drivers side left side under the dash clearly could see the mechanism moving up and down. Also passenger side bottom under dash too looks good.

At this point a easy fix was hard to find and my cousin at the garage said he will look into which remaining two is the one that could be at fault.

Very uncommon this is but not something that fails.

Any ideas welcomed… thanks

I recall you saying the cable was moving at the heater valve on the bulkhead, bearing in mind it only works with the ignition on. If the valve is opening as per your post, and water is flowing through the in and out of the heater and of course is hot (read very hot) then there this only leaves a partial blockage of the heater matrix itself, this would result in a serious reduction in the matrix being exposed to the hot water coming in.

In the garage I keep a couple of house radiator temperature gauges, they are placed on the inlet and outlet piped and held in place with a spring, they are used so you can check the radiator for silting or other blockage, I use them on cars for exactly the same thing.

Regards

Dave

Regards

Dave
 
Yes I did a flush for the matrix Dave all looked good no issues.
All pipes are very hot no leaks with engine running and dash temps on hot / normal. The lever on the firewall works fine. It’s didn’t seem to be the control unit at this point in the dash as the A/c works and all else is showing ok.
It’s clearly a leaver somewhere getting stuck or maybe a electronic module maybe the one on the matrix box I don’t know yet. What lead me here was after the flush it blow cold again and it’s stuck on that for now again when it was working as medium hot before in the weeks it got better thereafter.

Investigation continues….

Thanks
 
If the cable is moving at the valve and water is flowing through OK then the options are getting less. One of them could be a head gasket, as air gets into the system it can get trapped in the matrix and this is like having tubes blocked. I would get some temperature measuring devices before going any further, and of course change the thermostat.

Regards

Dave
 
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