disappearing coolant

Post by **cherry** » Thu Mar 27, 2008 11:19 pm

Hello chaps & chapesses, my radiator keeps emptying itself & I can't believe it's all going down the overflow pipe. when I switch off the engine after a run there's a lot of gurgling& i have to fill up with at least two pints of water before travelling again. it's a 1098 recon engine eight years & 60000 miles ago,with an unleaded head which was changed for a ported leaded one a couple of months ago as the old one kept blowing gaskets. water in oil & oil in water which I thought would clear a while after changing heads. no emulsion on dipstick can't see any water leaks, any ideas gratefully received.

Post by **bigginger** » Thu Mar 27, 2008 11:32 pm

Inspect all the joints in the rubber hoses, and if no sign of leaking, the radiator itself, which may have holed. Don't forget that the water flows through those pipes high up in the engine bay, which will have been disturbed during the head change
Andrew

Post by **kennatt** » Fri Mar 28, 2008 8:26 am

if you can find no obvious leaks,fill the rad and leave the top off let the engine run at tickover untill up to operating temp ie thermostat open then watch the level of the water in the rad.it should be holding a level,then standing back from the rad rev the engine and see what happens the level in the rad should fall slightly as the pump pulls water through the system. If it pushes water out then you probably have a problem with the head,ie gasket or crack.this presurises the system and blows water out of the rad through the overflow.Dosent take very long to drop the level and risk overheating Good luck

Post by **bmcecosse** » Fri Mar 28, 2008 11:17 am

Could be the rad cap is letting the water out - put a plastic bottle on the overflow pipe and see if it fills up during a run. Have to say - if no external leaks, and it's not just the cap - then it will be head or head-gasket problem.

Post by **cherry** » Wed Apr 09, 2008 9:24 am

Well i checked all hoses again no leaks, rad cap's not letting anything out so removed it and checked what was happening when engine was ticking over. water spluttered out quite forcefully until i revved it and the water level dropped and smoothed out. seems that water loss occurs when idling rather than at higher revs. still checking this though.

Post by **rayofleamington** » Wed Apr 09, 2008 4:22 pm

what was happening when engine was ticking over. water spluttered out quite forcefully until i revved it and the water level dropped

sounds like a small headgasket leak

However it might be from water boiling due to overheating.

As you mentioned gurgling sound after key off, I thought it fair to warn you that this is water boiling somewhere in the engine

i.e. it is overheating. This may be due to gas in the cooling system due to the head gasket failure, or may be due to some other reason (e.g. the overheating may be causing the other problems)

Post by **bmcecosse** » Wed Apr 09, 2008 4:30 pm

Well worth thoroughly flushing the system out - to get rid of any blockages. If it's really gungy - maybe try some drain cleaner in the system - but only for 10 minutes with the engine heating up and running it round - then drain off and flush with clean water again. Head gasket problem does seem quite likely though - when it blows it can cut a passage in the block surface - changing the head won't eliminate that.