2.1 dj thermostat housing bleed valve??

[toolsntat]

Would it be possible for this to block up as had it open and shut yesterday with no sign of air or water
Thanks
Andy

[Ian Hulley]

It's not unknown for the bleed ring to become blocked if someone's attempted to use radweld or some other quick 'fix'.

Ian.

[billy739]

slowly twist a small drill into it.

remove the bleed screw first.

[toolsntat]

Cheers Ian
By 'bleed ring' I assume you mean the thin pipes around top of engine bay..... but then these are all higher than the valve

Does the cap come off if you keep unscrewing and pry apart the little hooks?

[billy739]

all the pipes going to the upper bleed ring can become blocked.

as the engine warms all but the thermostat hose will get warm if there is no blockage.
the thermostat leak off will get warm when the screw is undone

generally this wont cause a problem if there is no air in the system, but once you have a leak/drain the coolant ect it can prevent the colling system bleeding and cause overheating.

the pipes from the head to the bleed ring can also become blocked especially the smaller ones.

the early bleed rings are metal ,later are plastic, however both will block up

[Ian Hulley]

There should be 4off M6 x 10mm(ish) setscrews holding the cap on, sounds like as Billy say's the spigot needs clearing out though

Ian.

[toolsntat]

Ah!!
Was expecting something to come out of the screw bit itself and not it venting into the (obvious) pipe out of it

Thanks for the info anyway folks as it does help immensely towards my understanding of these things

Antifreeze and its quirks are my next topic I think

Andy

[tencentlife]

Yes, if you gently pry apart the tabs either side you can remove the bleeder screw. The orifice inside is very tiny. That screw just ports the orifice to the air purge hose atached to the cap, correct, no liquid should come out of the screw, there is an o-ring down on the shank to keep the fluid in.

If you can't clear the orifice inside, an alternative that eliminates the need for that bleeder is to just drill a small hole, 1/16" will do, thru the rim of the thermostat itself. Many t-stats for other engines come with this out of the box, it lets a little bleed of water flow thru the disc when the t-stat is closed, not enough to have any effect on warmup but it helps the system to self-purge. The reason the beeder screw is there is because that big hose returning from the radiator is a dead-end until the t-stat cracks open.