Heat problem

[Davcud]

now the weather going cold finally put the heater on and yes its cold, Temp gauge is normal etc ,has anyone any ideas thanks

[heinkeljb]

Heater temperature gauge lever not operating the heater matrix valve properly? Air lock in the heater matrix?

[Mad smart person]

Greetings, to give an idea, if the lever goes back and forth without any friction, the end of the bowden cable is probably not fixed at one end? Either it's slipped off or the attach point has broken off the actuator arm?? Cheers.

[Buckster]

Are you sure it is not taking longer to warm up, it may be the thermostat, you can still see three blobs but have cool air if the thermostat is goosed.

[mottofreee]

What is Smart about? 450 petrol, 450 cdi, 451cdi, ...?
Heating systems differ.

[Davcud]

sorry its a 450 petrol it warms up as normal i.e 3 blobs on the dash , all switches move freely and are connected etc

[mottofreee]

450 gasoline is without auxiliary heater and the passenger compartment warmth is deficient due to the panoramic roof.
Also the rest of the thermal insulation is insufficient.
These issues can be remedied by:
- using a restrictor
- increase thermal insulation
-Adding an auxiliary heater

[tolsen]

Heater matrix on a 450 is being bled via expansion bottle which is attached to radiator. No sign of engine overheating indicates there is no air lock or air needing bleeding out of cooling system.

No heat in cabin when engine is warm can therefore only be caused by problem with heat control. Look in right side foot well and check whether heat control cable has come off the lever that operates heat control flap.

[heinkeljb]

Heating in a petrol 450 is perfectly adequate for British weather. If your thermostat is showing 3 blobs but your heater matrix when set to hot does not produce any hot air, then you have probable issues with the heater matrix.
The issue could be that the valve the lever on the console does not operate correctly when the lever is moved. - Stuck valve.
The pipes connecting the heater matrix to the rest of the engine cooling system are damaged. - i.e. blocked
The heater matrix is damaged. - i.e. blocked
There is a air lock in the heater matrix.

The most efficient way to diagnose any of these conditions is to take the front cowl off and feel the hoses coming from the engine and the hoses going to the heater matrix. From this you will be able to tell if there is hot coolant going to the heater matrix or not.

If the coolant pipes coming from the engine are hot, but the coolant pipes going to the heater matrix are cold, then the valve is at fault or the pipes are blocked. If the pipes going to the heater matrix are luke warm, them the issue is in the heater matrix.

John

[tolsen]

You can feel on outlet hose from heater matrix where it connects to expansion bottle. Access is through the left front service hatch.

[Davcud]

Thanks i will check all of these and let you know the outcome

[Davcud]

Right pipes to heater matrix are warm/ hot : pipe to expansion bottle is warm/hot :
BUT the rad in the engine bay is cold and never gets warm/hot and the engine now has started to overheat (just what i need )
am i now looking down the route of water pump

[Thrumbleux]

Rad in the engine bay is an intercooler and has nothing to do with liquid coolant or heating.
Water pump failure would cause engine to overheat and would probably be leaking as well. A leak there can also draw air into the cooling system which could cause an airlock. Check for leaks around the pump and for play at the pulley (if possible - belt tension may mask it) and for any signs of distress on the belt (caused by misalignment of the pump pulley). Are you losing coolant?
Just to be sure - your heater is BLOWING cold air - not not blowing. Correct?

[Davcud]

No leaks belts fine , The heater blows warm then goes cold , no signs of leaks no loss of coolant

[Mr T]

Sounds to me like you've got an airlock. Have you tried bleeding the system?

https://www.evilution.co.uk/index.ph...engine&mod=133