remind me - stuck thermostat?

[sgray]

At the weekend the heater in the car was only blowing cold air, even after a decent run. Doesn't that suggest the thermostat not opening (or is it closing)..? I don't have a temp gauge..

[bmcecosse]

Well - it could mean the stat is stuck open, or just that the valve to the heater is closed, or more sinisterly that the head gasket is blown and the water level is low! So - first check is water level - fill right to the top - run the engine and watch for bubbles - and feel the hoses (watch out for the fan). Some may suggest an 'air lock' - but in my experience this is only after the system has been emptied/refilled - and clears within minutes of running the engine. If all seems ok - take the stat out and inspect.

[sgray]

Well it's been a couple of weeks since I worried about the head gasket, so I guess it's due..

Popped out after your message and checked the water level, which is fine and hasn't moved since the run on Sunday. I can't run the engine in the garage without gassing myself, so will have to wait.

and just because I don't have enough to worry about I took these pictures - of oil around the first (last?) plug. I did check and top up the oil before taking her out at the weekend. It's definitely oil or oily water.
[frame][/frame][frame][/frame]

She's running really smoothly now but is still quite low on power (I think) - if that's a clue

Simon

[andrew.searston]

looks like oil pushing past the rocker cover
i would replace that and the head gasket just to be on the safe side.
might as well decoke it while your at it.

[mike.perry]

If you run the engine and and you can see water movement in the radiator header tank, go and have a cup of tea. When you return the top hose should feel hot.
Check that the heater wire onto the valve at the back of the cylinder head is firmly attached then push the heater knob inside the car fully in and check the position of the lever on valve. Pull the knob right out and check again. The lever on the valve should move the full range and with the valve in the open position the heater pipe should feel warm.
You can check if the valve is working by turning it off, disconnecting the hose, turning the valve on and revving the engine and you should get a flow of water out of the valve.
The oil around the back of the engine is coming from the rocker box gasket which needs to be replaced. They are nomally made of cork. General question, are rubber ones available?
Clean all the old bits of gasket and the oil off the cylinder head and the rocker box and stick the new gasket to the rocker box only with Hylomar. When it is dry then fit the rocker box in position without disturbing the gasket and pinch the two bolts up just tight.
Your lack of power could still be the timing is out. Have you turned the distributor to get the fastest tickover yet? Don't start taking the head off until you have checked everything else and you have done a compression check.

[bmcecosse]

The oil is just a dribble from the rocker cover - don't panic! The heater valve looks to be wide open - so - you need to decide if the whole engine is running cold, or is it just a lack of 'flow' through the heater that's the problem. As MP syas - let it run for a bit with the rad cap off - top it up right to the top - and watch if there is a stream of bubbles. If you can hold of a thermometer to measure the water temperature - do so!