While driving to the airport on Monday in 110F+ heat, the Grand Prix's cooling system wasn't working too well. My ODBII scanner told me the coolant was sitting at about 212F while cruising at a steady 65 mph. I got back last night and checked the radiator this evening to find:
I don't know what I'm looking at but assume it is either oil in the coolant or Dexcool sludge (although I thought the gasket issues leading to sludge were worked out by the 2006 model year). I did a full distilled water flush when I replaced the coolant elbows and thermostat (Stant SuperStat) 2 years/23k miles ago and only used Prestone Dexcool and distilled water for the refill. No additives, cooling system tabs, etc.
What is the likely culprit here and what should I do next? Take it to a shop to have the cooling system pressure tested? Do another coolant flush? I was already planning on doing a drain and fill while replacing the thermostat with an ACDelco unit and putting in some ACDelco cooling system tabs since I have heard that using the tabs is recommended even if there are not any issues.
I am starting a new job in a week and will have to make the 900 mile round trip twice in the span of two weeks until I can move my family out and do not want to get stranded in the middle of the desert with an overheated engine.
I don't know what I'm looking at but assume it is either oil in the coolant or Dexcool sludge (although I thought the gasket issues leading to sludge were worked out by the 2006 model year). I did a full distilled water flush when I replaced the coolant elbows and thermostat (Stant SuperStat) 2 years/23k miles ago and only used Prestone Dexcool and distilled water for the refill. No additives, cooling system tabs, etc.
What is the likely culprit here and what should I do next? Take it to a shop to have the cooling system pressure tested? Do another coolant flush? I was already planning on doing a drain and fill while replacing the thermostat with an ACDelco unit and putting in some ACDelco cooling system tabs since I have heard that using the tabs is recommended even if there are not any issues.
I am starting a new job in a week and will have to make the 900 mile round trip twice in the span of two weeks until I can move my family out and do not want to get stranded in the middle of the desert with an overheated engine.