General No hot Air

[Italian Job]

guys help please

Punto mk2 8v. I no hot air coming out of the heater. I have bled the system as per the guide. Both hoses input and output to the heater matrix are hot. Checked the hot /cold flap and its working OK. Temp gauge reads half way (normal)

Any ideas
THanks

 

[rallycinq]

Stuck cock?

Cheers

D

 

[Italian Job]

Stuck cock?

Cheers

D

Please explain

 

[SamuraiDragon]

*bites tongue to stop any comments that are in any way seedy.*

 

[ChrisUK]

Think he means thermostat.

 

[Italian Job]

but both top and bottom hose are hot and it would get hot after a long run which it dont.???????????? and also the temp guage is reading correct.

 

[RB2009]

Clogged heater matrix?
if the heater matrix is clogged, the hoses will heat up still because the heat from the coolant in the pipes which they are connected to will heat them up.

but if theres no flow accross the heater matrix you wont get any heat.. had to change a few earlier on in the year, car just wasnt getting hot inside.. pulled the heater matrix out and all the waterways inside were clogged.

could also be thermostat although if the thermostat was faulty, then the engine would take a long time to warm up.


other things to check are the flaps inside the heater box are moving properly and its not stuck on cold or something which would block any heat

 

[D4nny8oy]

There is no 'valve' to control coolant flow into and out of the heater matrix.

If both pipes are hot, then it suggests the cable/gear system linking the temperature knob and the flap covering the heater matrix has broken/come adrift.

You need to lay in the footwell (not sure which side) and look up under the dash while turning the controls and see if you can see what has caused the temp. control flap to stay on 'cold'.

 

[rallycinq]

If its an air blend system then its flap trouble or a blocked matrix.

If its a water blend system, its cock trouble or a blocked matrix.

Everything else you've done is fine.

If the matrix is working properly one of the pipes should be a bit colder than the other, after all the matrix is supposed to take heat from it.

If coolant is not flowing the water will get hot from both sides just from the engine heat.

Cheers

D

 

[Italian Job]

Can you tell me if the bled screw is on the input or output to the heater matrix. Tomorrow i will try and back flush it and see what happens.

 

[D4nny8oy]

Check the operation of the heater control cables first- takes 5 mins to ensure the mechanism is moving fully in both directions.

 

[Italian Job]

will do

Thanks

 

[Italian Job]

Thanks guys
Checked the hot / cold flap control and all ok, so i disconnected the matrix pipes and back flushed refilled with paraflu and bled the system, now I have and nice hot car.

Thanks again for all your help.

 

[DaveMcT]

Air was in the cooling system because coolant leaked out so there has to be a leak somewhere.

Check the radiator, water pump & core plugs for leaks and dont trust the head gasket for long term reliability as its been stressed.