I thought crap- blown head gasket today. No over heating, no excess or any steam from exhaust, no coolant in oil dip stick but should I be concerned bout build up of dark brown scale on rad cap? Slight milk under oil cap and sump looks clear still. A15 did it too. Would it be just condensation build up from catch can again?
Just wondering if it's just scale from sitting or crap from the block. It's not head gasket sludge like I've seen.

I haven't driven it for 2 weeks. Just took for a drive and felt fine and no overheating etc. Still no steam from exhaust. There was some vapor from oil catch can, so left car running and took of oil cap. Big waft of vapour and no slight milk on oil cap.

Figure it's just condensation so incentive to drive more but concerned bout scaling.

Spoke with piggy, he reckons get an exhaust gas analyzer on rad to check if it's exhaust gas in coolant.

Any ideas or thoughts in it.