Exhaust: Heater valve spring

[christophe]

HI folks,

I'm a little bit puzzled by my heater valve (OHV6). As its spring is said to be thermostatic, I thought it closed the valve when cold and opened it when hot. In fact, the valve is always closed when hot on idle and opens only on acceleration.
Is this the normal behaviour?
Everything has been overhauled and the spring is brand new. The weight is in the right position.
It is not very annoying but the exhaust line is very long to warm up when the car is on idle, therefore I get a lot of condensation and smoke.

Nice day to all.

[SN-60]

To christophe,----- Normally, those 'heat riser' valves slowly open as the engine comes up to temperature, and remain fully open when the engine is all warmed up and running.

[christophe]

Thanks Ed.

That's what I thought. Don't you know where I could get a real thermostatic spring? Mine came from S.I. but obviously doesn't make the job.

[warrlaw1]

Check the valve, itself, on the exhaust manifold. Sometimes they sieze up.