thanks Fred

a bit more info in order to contextualise things.

i took the old therm out a while ago because it got knackered. it got
knackered because i poured some 'rad-weld' type stuff in to stop the rad
from leaking. subsequently changed the rad but couldn't get hold of a therm
for love nor money until yesterday.

btw, tried the thermostat in hot water routine. opened up but only when
close to boiling point. will see if there's a different type available that
opens a bit sooner.

thanks again for taking the time

mojo

"Fred W." <Fred.Wills@'remove this to reply to' myrealbox.com> wrote in
message ...
>
> "mojohotmail" > wrote in message
> .uk...
> > Thanks for that, Jim. forgot about the thermostat experiment in a
saucepan
> > of water trick - will do in the morning. the engine and circulation was
> > fine
> > before i tried installing a new thermostat. as i said earlier, the car
> > came
> > without a thermostat fitted. at present, no thermostat and circulation
ok.
>
> ...which would make me nervous. Why had the t-stat been removed?
Somebody
> was apparently attempting to circumvent some sort of cooling system
> problem...
>
> How do you know the coolant circulation is adequate? Without a thermostat
> the wide open path may allow enough coolant flow (even with a bad pump?)
to
> keep the temps down and allow the hoses to get hot. While it is not
rocket
> science, I would believe there is more to the problem than just the -stat.
>
> Also, when you do put the new -stat in, there should be a small hole on
the
> upper part of the large disc. It may have a little poppet in the hole or
> may just be a hole. This is there to allow the air trapped behind
the -stat
> to pass when you are filling the system. If you trap air in there it may
> boil over due to the uneven cooling.
>
> -Fred W
>
>