a good check for cylinder head problem, check underneath oil filler cap if there is a lot of whitish creamy residue here ,this is water mixing with the oil and emulsifying, if this is the case, get an engine compression test done takes about 60 mins to do, as to your other comment, brown water in the cooling system indicates rust, after successfull flushing, water should run clear, this is important, as residues in the system will contaminate your new antifreeze, I suggest check all hoses for tightness and condition, they should be flexible to the touch and not cracked, if all ok fill system and open any bleed screws if fitted this allows any air in system to escape, if air remains in system heater will not work properly, it may be helpful to purchase a haynes manual about 14 pounds from halfords, this topic covered in detail and troubleshooting tips also. good luck r dalton
r dalton, January 2009