Coolant Loss From Axpansion Tank Cap

[Alistair E]

I seem to have some problems with my waterworks and have had for some time. I'm currently topping up the system on a regular basis so it's time to ask for some advice and try and fix the problem.

I'm losing water from the cap and don't seem to be able to stop it, despite replacing the cap. Everything is fine until up to temperature. Then I end up with the cap leaking, sometimes until the expansion tank is completely empty. I've tried bleeding the system and this appears to be successful but it's not fixing the problem.

The system appears to be over pressurised but I'm not sure if this is the case. Nothing milky on the oil filler cap so no indication that the head gasket gone between water and oil.

Any suggestions gratefully received.

Thanks

Alistair

[steve briance]

Would it be time to get a sniff test done on the coolant to see if it is combustion pressure forcing the coolant out? A small crack in the gasket between combustion chamber and coolant channel wouldn't necessarily mix oil with the water...

I don't have any advice as to where to go but I guess contact a reputable garage and ask them if they have the kit.

How is the temperature when running? Emptying the coolant bottle sounds like it being forced out quickly / boiling / leaking.

[Error404]

I’d check the tank for a crack or damage around the neck / thread. If that looks fine, do a sniff test.

Dont leave it too long if it is a headgasket leak it will soon start erroding the head face and cause more damage.

[De80q]

I had the same problem on my 10vt swapped 80q. turned out to be more than one crack in the head gasket. Changed the gasket, and haven't had the problem after.

[Alistair E]

Thanks guys. I'll the sniff test done.