Lotus Elan and Lotus Elan Plus 2 Forums

I've just had the radiator on my S2 recored and, after running a few miles, there is contaminant in the coolant. It is honey coloured and looks like an emulsified light oil. The engine has also just been rebuilt by a reputable twin cam specialist. Clearly I'm hoping the cause is not head gasket. Could it be flux residue from the recoring process?

Any thoughts much appreciated.

Vernon

Honey coloured? Emulsified engine oil always seems to go white in coolant in my experience, but perhaps modern oils are different.

I would have thought that rad re-corers would flush the rad after soldering, but an easy test would be to drain and flush your system (a garden hose in the top of the rad with the bottom hose off should do it) and re-fill. If the problem goes away it was something nasty in the rad that has been flushed out, if it reoccurs, then its on the phone to the engine builder.

Good luck.

Thanks Andy

Vernon

if it's a small quantity of oil gathered up at the top of the radiator (remnants of the assembly process possibly) you'll find out easily after flushing or moping out the top part... if there is somehow pressured oil pushed into the cooling circuit under operation you'll soon see issues with the oil (that you may want to monitor carefully, as when turning off the engine the cooling circuit is likely to push coolant back)
Imho chances are the first is more likely, esp. from a reputable builder...

keep it on the road !

Thanks, wise words indeed.

Vernon