Header tank blow back

[handyman]

Coolant problems again

Does anyone know what causes coolant to be forced through the overfow pipe in the header tank?
Getting a bit miffed now what with replacing 2 hoses and a thermostat and after a week of checking the levels am back to square one with perhaps the same problem I had before changing the bloody thermostat!

Perhaps there is still air in the system??

[321Away]

sounds like an air lock, system needs bleeding

[rita]

Hi,
Have you checked your cap?

[handyman]

Think it might still be an air pocket, thanks 321,

Have already swapped the rad cap with the header tank rita.

Thinking of consulting Basil Fawlty.

[Ian]

Try shouting at it. And if that doesn't work, shout at the missus....

[dunslair]

But whatever you do.....Don't mention the war.... I did once but I think I got away with it (jap motors can be a bit touchy too you know)

[handyman]

Done that one already Ian when the poxy thermostat went.

Better, i'll give it to the Taliban , Bongo's love hot weather especially when there's an air pocket..should blow up nicely.

[bigdaddycain]

Coolant problems again

Does anyone know what causes coolant to be forced through the overfow pipe in the header tank?
Getting a bit miffed now what with replacing 2 hoses and a thermostat and after a week of checking the levels am back to square one with perhaps the same problem I had before changing the bloody thermostat!

Perhaps there is still air in the system??

Hi, Under what circumstances does it start to spew the coolant back out of the header? Is the new stat actually opening?

[missfixit70]

Silly question, but you aren't overfilling the header & it's just blowing out the excess?
When you bleed it, is the bottom hose getting hot?

[handyman]

BDC and Missfixit

The thermostat is opening on the last bleed I did a week ago. Bottom pipe hot.

I have been topping up to bring coolant level to the full mark.

For instance this morning I dipped the header tank and it was at min. So I topped it up to the full mark and 3 miles later with the needle at 11am I stopped at work and smelt burnt coolant, popped the bonnet and saw that coolant had blown through the little header pipe and the front fans were going ( forgot that bit this morning)

So left it to cool untill lunchtime and found that HT was down to min again. So I topped it up again and gingerly drove home.

Luckily the wife is in York on a course so I pinched her car back to work.

Reckon I will have to bleed more thoroughly. Never mind the Taliban. I might blow it up myself.

[missfixit70]

Are both heaters geting hot? it has been known for the front matrix to block, causing airlock problems. Could it be a small leak somewhere allowing air in?

[Doone]

Handyman you have a pm.

[bigdaddycain]

BDC and Missfixit

The thermostat is opening on the last bleed I did a week ago. Bottom pipe hot.



Reckon I will have to bleed more thoroughly. Never mind the Taliban. I might blow it up myself.

How did you bleed it Handyman? If the bottom hose got hot upon bleeding then that's a fair sign that it's bled up "ok"... If you are seeing poor or fluctuating heat at the rear heater you could well have an airlock in the rear heater matrix.

[Simon Jones]

If the problem remains after bleeding it several times, then it suggests you've got a head gasket problem which is resulting combustion gasses getting into the coolant .