Streetka heating irregularity

[Russ 6334]

Hi all

 

just bought a streetka as a second car, really good condition only 65k miles and virtually FSH only paid £600!! Bargain 

 

I've sorted the indicator fault with alarm by disconnecting the alarm but now have a heating issue.

 

now I know they are prone to overheating but mine is quite the opposite. It gets warm, heat comes out of the heater matrix then suddenly it goes cold again until it may get warm again.

 

at first I thought the thermostat was stuck open and the engine was heating then on faster roads cools down which would explain it but I stripped the housing down tested the thermostat and its fine.

 

also I've noticed it could all be town driving low speeds where the radiator isn't cooling efficiently or on the motorway where it is but still plenty of heat comes out then suddenly freezing cold?

 

ive tested thermostat and fully flushed the fluid and squeezed all air bubbles out.

 

any ideas? I'm completely lost?

 

still happy it's underheating not over heating!

 

the engine stays warm though the whole time as tested with heat gun!

 

russ

 

[Russ 6334]

Well after changing the thermostat no change, was advised to change the thermostatic control unit under the windscreen, changed this and again no change.

 

i have an infrared heat detector and the temp going in and return from heater matrix is 90 and about 85 degrees and the heat out of the cabin when on cold is 70 degrees! It's baking

 

so basically electrically something isn't telling that control valve to recirculate back to the engine.

 

does the temp dial in the cabin have a resistor on it? To control the flow return to the engine?

 

any help would be appreciated I'm baking in the cabin!

[Russ 6334]

Meant to add all fuses are in tact checked everyone!

[137699]

The Heater Control Valve needs replacing. A very common fault.