coolant level

[copilot]

I've not had my cerb very long and have noticed the coolant level does drop to the bottom of the filler tank (although does not appear to drop any further). I top it up when cold to the correct mark i.e.where the join is on the tank, 40 mile later its low again. Does the car loose fluid through expansion when hot or should I start looking for a leak?

[ridds]

I'd start hunting for a leak.

[thegreengoblet]

You can also over fill it which will lead to water loss through the expansion cap when the engine has been run for an hour or so. I remember only topping my up to half way once and it all blew out after a long blast! Also, ensure that the cap is done up tightly. It could be escaping through this route and you're not noticing it. I was told that as long as you can see some water in the expansion tank, then that's fine. I pressume you haven't noticed any rise in running temp? I presume that your fans are kicking in ok?

[copilot]

The engine temp appears to be fine. Fans cut in at arround 105 degrees. The coolant level drops to the extent that you can see the holes at the bottom part of the header tank, but does not drop any further....yet

Edited by copilot on Tuesday 21st November 21:53

[copilot]

ridds said:

I'd start hunting for a leak.

mmm...that's was my first thought.

[SI-PEN]

Probably leaking from top of rad where the rivets are on each end. You'll never notice it as it dries after leaking but enough to show a short fall in the expansion tank after 40 miles.

Si

[copilot]

SI-PEN said:

Probably leaking from top of rad where the rivets are on each end. You'll never notice it as it dries after leaking but enough to show a short fall in the expansion tank after 40 miles.

Si

...I'll have a look, thanks.

Edited by copilot on Tuesday 21st November 22:00

[keithyboy]

Make sure that cap is screwed up nice and tight

[gazzab]

the rubber hoses can perish and develop pin holes.

[ridds]

Worst case will be head gaskets and have heard of a fair few of these going now.

[southendpier]

ridds said:

Worst case will be head gaskets and have heard of a fair few of these going now.

happened in a car I once had, Omega 3.0 24v no body could find the leak - including main vauxhall dealer, but the fuid kept running out....then bam BIG engine problems as the oil and water decided to see if they could get along with each other.

get it checked ASAP.

[gazzab]

Any engine running too hot will cause premature engine wear (eg glazing and valve guides). The Cerb engine bay is very very hot and so it is very sensitive to too much heat (in my 2 x rebuild experience).

[methodwares]

I've got the same issue, but i have noticed that one of the bleed stop cocks on the coolant tubes along the side of the engine has some dried antifreeze on it. so it looks like that may be causing my leak.

some you can do to check for a blown gasket (other than finding the white sludge in the crank case) is once the car is getting warm (not normal running temp) take the coolant fill cap off and wait for the water in there to start getting nice and warm (hot) which will indicate that the thermostat has opened. once this has happened, fill it up so it covers all the holes in the bottom if the expansion of the water has not done this. Now look for gas bubbles comming out. This will indicate if there is a blown gasket as hot gases are being forced into the coolant.

[ridds]

You can also buy a "combustion gas sniffer" that you can plug into the expansion tank and it will tell you if you have gas in your system.

[V800MPH]

I had a similar problem a few years ago,it turned out to be the header tank itself that was leaking,you could smell burnt coolant fluid,but no sign of fluid on the garage floor,so i presume it leaked only under pressure around one of the plastic moulded areas.I was told by TMS that they had had several cerbs with the same problem at the time.Hope it helps certainly a cheap fix.

[marcus1970]

Be very careful here. Best thing to do is drain the whole system and then fill it back up again until your sure you have as near as 12 litres in there as possible because - the expansion tank may only look as if it is empty to the bottom - ie you can see water. However mine looked like this and I was still able to add another 6 litres of water before it was properly full again (left top off and 6 litres emptied/bubbled onto the promenade at the beach).

I didn't drain the whole system but did this...Topped up tank to an inch or so from the top. Ran the car til it hit around 85/90 degress - no higher - and turned car off. Slowly - very slowly undid the filler cap until I heard a faint hiss - this was the air escaping under pressure. Did not undo any more. Kept going out to car until hiss had stopped. Added .5 to 1 litre of hottish water (not boiling but more than warm - about 65 to 70 degrees of water) and repeated the whole process until eventually when I took the cap off the water was still pretty much upto the top of the expansion tank. This will mean that the system is pretty much as full as it can be - 12 litres roughly. Checked this after each drive and topped up if necessary, whatever happens you don't want to be driving around with very little water, as your engine will go bang eventually.

Next, like the others said you need to find out where the leak is coming from (usually denoted by crusty coolant marks in white, light blue or light pink - dependant on your coolant additive). Good places to look are around the radiator, bottom of expansion tank, jubilee clips on coolant hoses or at worst round your head bolts / seals..

Good luck...

MB