Radiator problem

[lloydy]

Noticed the temp on my 1.6td was getting pretty high, felt radiator-cold. Big pipes going to it cold to slightly warm, smaller pipes nice and hot.
Pressure tank and expansion tank have correct levels. Checked the darlek cap and i could suck and blow through it. Undone bleed valve on radiator no water or hiss.
Will a faulty darlek cap stop the system pressurising enough to be able to fill the radiator up?
I hope so as i've got one coming tomorrow
Cheers, Lloyd

[kevtherev]

is the thermostat opening?

[16vmini]

Would the t/stat stop water getting to the radiator?

yes , basically stops the water circulating untill it thinks the engine is warm enough ( gets engine upto temp quicker .. well thats the idea )

can be tested by sticking thermostat in a pan on the hob of boiling water ... watch it open ... make sure wife is not around

Matt

[lloydy]

Would the t/stat stop water getting to the radiator?

yes , basically stops the water circulating untill it thinks the engine is warm enough ( gets engine upto temp quicker .. well thats the idea )

can be tested by sticking thermostat in a pan on the hob of boiling water ... watch it open ... make sure wife is not around

Matt

Soooo the stat cuts off both flow and return to radiator? Hmmm hoping its just the cap then, don't really want to be draining the coolant

[16vmini]

well flow and return in my mind is the same thing .. maybe vw works a bit different , only saying what i have learnt.
if the hose is cold that comes out of the thermostat , then i would have said that its the cause...

but as i said still learning..

Matt

[jed the spread]

don't really want to be draining the coolant

Be prepared to get your arms and armpits wet when changing the stat then

jed

[Ian Hulley]

You shouldn't be able to suck and blow through the dalek cap.

Ian.

[jed the spread]

Doent it start to dump the coolant through the expansion tank when hot if the cap is duff?

jed

[lloydy]

You shouldn't be able to suck and blow through the dalek cap.

Ian.

My thinking was if cap is faulty, system won't pressurise and i wont get any water to the rad. I don't think the guy i bought the van off filled the sytem properly, as i noticed this problem on it's first run

[kevtherev]

the pipe FROM the rad to the thermo housing is cool

[lloydy]

Looking at that diagram water can get to the rad if the stat is broke [not circulation, just being able to bleed]
So could just be a pressure issue which could be fixed with a new cap, or could be a blocked radiator

[kevtherev]

indeed it could be blocked ...and not uncommon
simplest job first would be to remove the stat... while it's testing run the engine without it and see if the circulation returns

[lloydy]

Cheers mate, I bought mine straight after a top end rebuild. It got trailered to me, noticed engine temp hot while I was letting van idle on my drive. Checked rad which was cold, tried to bleed but got no air or water. I'm hoping it's the cap not letting the system pressurise, but could also be the rad. Fingers crossed it's the cap
Lloyd

[..lee..]

air lock, t stat faulty, rad blockage or water pump fault will cause lack of circ` the pressure cap in itself wont cause a circ` fault but will cause the van to "overheat".

[lloydy]

If the system doesn't pressurise properly, I was thinking you wouldn't get any water or air into rad, due to it being higher. I've got a cap and t/stat on it's way (should have arrived yesterday)
Im sure it's wishful thinking, and it will be something more expensive The smaller heating pipes get hot, so I think that means water pump is working? So might well be a blocked rad