I took the holden from matamata to napier on friday, she overheated twice on the way down, so flushed the radiator and block with the garden hose, drove it, still dumped all its water out the overflow, then noticed a lil steam from the exhaust but no water on dipstick and thought head gasket so dropped a cylinder head sealer in as a temporary fix, still over heated probably quicker than before i have checked the water pump is ok, gave the radiator another flush and got a fair bit of crap out of it and it seems to drive ok but lost a lil bit of water so am still wondering if its the head gasket. what do you guys reckon??