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Discussion Starter · #1 ·
Hi guys,

Issue I have is the heater blows cold air. Not a hint of warmth out of it (A/C works fine). Have turned the temp dial up all the way to 'Hi'. This is after the engine has had plenty of time to warm. Coolant level is fine and no evidence of the level dropping over my 6 months of ownership.

Given this is actually blowing cold, could it be the heater fan or does that indicate the fan is working? Is it more likely to be a blocked heater radiator, in which case, is there anything i can do to try to unblock? Is trying to unblock risky for the pipes?

I've had a good look through the forum posts and see related articles but nothing with quite the same symptoms I have. Please feel free to point me to generic troubleshooting articles if you think this is relatively commonly documented.

1.8L Petrol '56 plate 4door

Please let me know if I can provide more information. Really appreciate your help.
D
 

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Petrol engines usually heat up far quicker than diesels to produce hot air in the cabin. Sounds as though the coolant is not circulating. This could be due to an airlock in the in the heater heat exchanger which would mean bleeding out the air or a mechanical problem in the mechanism preventing the coolant circulating or the heat exchanger being blocked. . Sorry don't have a Gen8 to be more specific.
 

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Discussion Starter · #4 ·
Can you hear the heater fan blower working when you turn it up?
Sorry for late response. Been a tricky Xmas.
When I turn up the fan speed, naturally that makes more noise. When I increase the temperature, there is no change in fan noise..
Could that mean a duff fan?
 

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is temp gauge going up?
if im not wrong a few have had the actuaters stick or stop working to controll the valve to let the warm water through the matrix
 

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Discussion Starter · #6 ·
is temp gauge going up?
if im not wrong a few have had the actuaters stick or stop working to controll the valve to let the warm water through the matrix
When I turn the circular dial, the digital reading goes up through the 20's til it says 'Hi'. I don't know of another gauge.. where can I find it?
Thanks.
 

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the cars temp gauge to tell you its running at normal temperature and not over heating
the 1 in the clocks think its opposite side to fuel gauge
 

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Heres a link to a thread about the blend door actuator. Check your is working when you adjust the temperature.

 

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Discussion Starter · #9 ·
the cars temp gauge to tell you its running at normal temperature and not over heating
the 1 in the clocks think its opposite side to fuel gauge
Oh, yes the engine temp is good. About half way typically..
Will have a poke around this morning see if I can hear the heater fan/knock it into life..
 

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Discussion Starter · #10 ·
Heres a link to a thread about the blend door actuator. Check your is working when you adjust the temperature.

Oh this is interesting. I can totally believe it might be this. Will take a look.
Looks like the white plastic pulley shaft might go right through the black box so hopefully I can feel whether it's turning without removing it?..
 

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Oh this is interesting. I can totally believe it might be this. Will take a look.
Looks like the white plastic pulley shaft might go right through the black box so hopefully I can feel whether it's turning without removing it?..
that was the thing i was trying to think off
 

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Discussion Starter · #12 ·
Everything seems to be in order. Actuator moving, fan noise changing from cold to hot, believe this is going to be a clogged heat exchanger... Anything I can try before writing it off as not economically viable?
 

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I guess you could find the pipes on the engine side of the bulkhead and see if they are getting hot on both inlet and return.
 

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Discussion Starter · #14 ·
I guess you could find the pipes on the engine side of the bulkhead and see if they are getting hot on both inlet and return.
Could these be them? See first pic with blue and light green knobs on. One is significantly wider than the other, the thin one is warm to touch, the thick one is ice cold.
Motor vehicle Vehicle Car Automotive design Auto part

Second pic is the same pipes going behind engine and into back of dashboard..
Automotive tire Hood Motor vehicle Automotive fuel system Automotive design


Not sure if I have the right pipes here but I don't see any obvious other pipes disappearing into dash..
Can anyone tell me whether I have the right pipes for the heater and what the knobs are for? Should I try turn them??
Cheers!
 

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Discussion Starter · #16 ·
I think those are the aircon pipes as those caps cover the valves that allow for gas recharge etc.
Only other pipe I can see is this black one right at the back. Difficult to see let alone trace. 😕
Could that be it? This could be where I nope out of this..
Motor vehicle Automotive tire Hood Automotive fuel system Automotive lighting
 

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Discussion Starter · #17 ·
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This looks more like it. They are quite far back. I managed to feel them both after having the engine rev for a good few mins. Neither pipe is warm to touch.. nothing like the temp of the radiatior which is getting hot..
 

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That last picture looks like them. Could be an air lock in the heater matrix. I assume those pipes have the factory crimped clip as opposed to a jubilee style clip? If it was an airlock if you removed the top hose on air should come out, followed then hopefully by coolant.
Does the coolant in the radiator look good and is blue? It could well be a blocked heater matrix if the wrong coolant has been used.
 

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Discussion Starter · #19 ·
Good suggestion. Theye look like factory crimps. Will try see if I can work top one loose assuming I can get far enough in!
Cheers.
That last picture looks like them. Could be an air lock in the heater matrix. I assume those pipes have the factory crimped clip as opposed to a jubilee style clip? If it was an airlock if you removed the top hose on air should come out, followed then hopefully by coolant.
Does the coolant in the radiator look good and is blue? It could well be a blocked heater matrix if the wrong coolant has been used.
 

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If the radiator is getting hot and the engine is not overheating that would rule out a failed water pump. The temp gauge sit just below the half on the dash?
 
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