Not sure what to suggest but I would check that when it gets to operating temperature that both hoses are about the same temp. If one is cold then the thermostat may have failed closed. One of those IR Temp sensor guns could be handy.

Otherwise, you may need someone to test it I believe there are test kits to detect exhaust gases present in the coolant.

The other possibility would be a bad water pump. I'm not a fan of miracles in a bottle. Totally clogged my cooling system once, stopped the leak too.

 

Thanks Gerard

My thinking now is I'm getting air into the system from the head gasket which is then over heating and expanding ,thus pushing out my coolant into the expantion bottle due to higher pressure, I don't think it's a simple case of airlock due to changed radiator. Everything gets hot and the top hose doesn't get rock hard until the thermostat opens but then it blows into the bottle.

 

Terry
Did you find the problem, I have done exactly the same, loosing water, new rad and now on long drives coolant is pushed into expansion tank.

 

Same problem here - any solutions on this?

 

Unfortunatelly, this is a common problem of this engine. It's head gasket. To be accurate - not head gasket but head deformation. No coolant in the exhaust because exhaust leaks to the cooling system - not vice versa. You loosing coolant through the expansion tank which is not pressurised by design - not through radiator. Do exhaust in coolant test

Cracked EGR is also possible however many topics on the forum point to the head gasket.
Regards,
Yuriy

 

Egr cooler can cause this. Likely cracked