head gasket?

[rubberhead]

hi all, done shepton mallet yesterday and on the way home boiled up a bit.pushed water out of rad into bottle,overflowed ran onto floor.very frothy water in bottle,strange but when I carefully released rad cap no pressure in system,poured water from overflow bottle back into rad and drove the last 10 miles a bit steady.
when I got home checked bottle to find about 3inches of water in it.rleased cap no pressure ?,I will confess to not sparing the horses on the way ,but why no pressure in system.last week I cleaned cooling system out as the water was a bit rusty,ran a rad flush for a few miles ,let go ,removed stat,flushed system ,refilled with new antifreeze,[tested stat].wondering if that is what the frothy stuff was..any idea why no pressure in system?.
whet for run today and water still pushing from rad into bottle.poss h ead gasket .oh and the bottom hose doesn't appear to have any water in it.

[Nick Jones]

Ah ha - then it was you I passed yesterday (driving Audi soot monster rather than my own Vitesse) apparently in convoy with rather slow Herald convertible - I overtook him but passed you when you pulled into a layby a couple of miles short of Keynsham .  Your car looks very nice.

Assuming that you are not loosing water overall (other than what is being blown out), rad pressure cap might be the first suspect - and also be aware that even if the rad cap itself is ok I've come across a couple of instances where the rad neck does not match the sprung length of the cap which also prevents it from holding pressure.  Foaming might be something to do with traces of the rad flush remaining or might be due to vigorous local boiling due to the system not being under pressure.

HGF indicated by bubbles in coolant smelling of exhaust (pretty severe), cooling system pressurises immediately the engine is started (pipes go hard), steaming exhaust even when warm, lots of mayo in the rocker cover or on dip stick.  No convinced this is your problem at this point.

Nick

[rubberhead]

thanks for the advice nick,will check out cap and reflush engine and try again.yeh mate that was me just outside keynsham waiting for my mate again.he has a spitfire engine in his convertible so he should keep up but he is more for the cruise/pose.we always go to shows together,he is like a talking Haynes manual.very clever man.
thanks for the coments about my car,makes 2 hours polishing worth it .will have to train the wife to do it.

[rubberhead]

dropped water from car flushed completely,think I got a faulty heater valve so just ordered new one along with new stat and will see where I go from there.