So............Do any of those bodges in a bottle actually work? (k-seal, bars-leaks etc). or will a retorque of the headbolts possibly help?
Sodium silicate can be used to fill gaps within the head gasket. Commonly used on aluminum alloy cylinder heads, which are sensitive to thermally induced surface deflection, and can be caused by many things including head-bolt stretching, deficient coolant delivery, high cylinder head pressure, over-heating, etc."Liquid glass" (sodium silicate) is added to the system through the radiator, and allowed to circulate. Sodium silicate is suspended in the coolant until it reaches the cylinder head. At 100–105 °C sodium silicate loses water molecules to form a glass seal with a re-melt temperature above 810 °C.A sodium silicate repair will last two years, sometimes longer. The repair occurs rapidly, and symptoms disappear instantly. This repair only works when the sodium silicate reaches its "conversion" temperature at 100–105 °C. Contamination of engine oil is a serious possibility in situations in which a coolant-to-oil leak is present. Sodium silicate (glass particulate) contamination of lubricants is detrimental to their function.
Has anyone had joy with tightening the head bolts another 45 degrees (TTY 10.9 bolts) to nip this sort of thing in the bud?
... it's what they used to bake the motors in all the cash for clunkers cars to insure no parts could be used to repair other cars.
I always hated that stop leak stuff.