Engine?cooling problem?

[dec]

ny help will be much appreciated.
Thanks Dec.

[NOT ANOTHER LEAK]

hi dec,you dont exactly say what the promlem is,
nice to have someone else from preston theres quite a few of us now,have to arrange for us all to meet up sometime

[dec]

Ill try again! Had a new engine fitted 1 year ago. Problem is expansion tank is being pressurised - which after only 1 mile from cold engine- water blown out into overflow tank and low level water light comes on, after every short trip i have to top expansion tank up. Im not losing any water its just being pressurised and blown out. Question is how do I pin point the problem. Is it a head/barrel gasket problem or a crack in a head or what.
Engine runs ok, compression tests all 4 cylinders about 150/160 psi.
Any help will be appreciated, thanks Dec.
p.s. this is the first time on line (in chat rooms etc)so bear with me while I get the hang of things)

[Louey]

presuming it is a petrol beast??

Perhaps the coolant system hasn't been bled properly, that would be my first port of call.

[NOT ANOTHER LEAK]

assuming your in preston lancs,if you need a hand(ive bled my van more times than i can remember)pm me in i`ll come round and help you

[Diamond Hell]

H'mmmmmm, the pressurisation of the water system is a sympton and bleeding the system is a temporary remedy, but the issue here could be that you're not treating the root of the problem.

NAL - how is the air getting into your coolant system? Sounds like there's possibly a small leak (yes, another leak) which is allowing air to be drawn into your system as the van cools down - hence you're having to bleed it regualarly. Check the pipes under the van, especially the large one on the left hand side of the engine bay as you peer down on it from above. There's a T in it that corodes - caught the one on mine just before it rotted right through!

Dec, take NAL's generous offer of a bleed up of the cooling system, but if it's suddenly started pressurising the system, unless there's been a very slow leak, then something's changed/broken/is breaking on your cooling system.

Inspect all of the pipes carefully for leaks etc. Mocki has suggested putting paper or card under the whole length of the van for a few hours to find the source of the leak by catching any drips. If that doesn't reveal anything then you need to get the coolant 'sniffed' for carbon monoxide (quick AA or RAC job if you're a member) - it's possible that combustion gases are being blown into the coolant from combustion chambers due to a blown head gasket, or cracked head. This may only happen when the engine has warmed up - hence OK combustion pressures at rest.

Good luck and welcome to 80-90.

[NOT ANOTHER LEAK]

dec is the thermostat working ok,does the heater get hot?

[dec]

Thanks for all your replies. Some further information. It is a petrol 1915cc.
I think i've bled it OK, Ive followed the detailed instruction as per brickyard site. Im not losing water (under vehicle). At the moment Ive got the thermostst out (I have a new one ready to fit). The heater and all the pipes to rad get hot. Diamond Hells suggestion seems ok except everything gets pressurised befor the engine gets really hot. The coolant "sniffed" idea to check for combustion gases appears to be the route to follow. Do garages do this test? If it is a head gasket or cracked head can it be pin pointed ie which cylinder BEFORE I strip the engine.
Richard (member no 2278) give me a call on 01772 687124 and I will take up your offer.

[Aidan]

Your local radiator specialist will be able to do the sniff test, if not a decent garage, just be a case of ringing around to find one that has the tool, and is prepared to do it and not charge the earth. Difficult to pinpoint which side is leaking as the coolant passes through both sides before the expansion tank iirc.