i have a 2004 outback 3.0 that started overheating 3 days after i purchased it. I had the obveous replaced; heat sensor. radiater cap. When I went to rewplace the thermostate I found that it had been removed. Put in an after market therm and it didn;t change situation. I replaced water pump. That didn't work. Situation now is that the two upper hoses get hot quickly and are under pressure; lower hose is much cooler and not pressureized.Logic dictates either a bad therm (but it overheated even when the therm was removed) or a bad radiator (but the radiator seemed to pass water freely when I had it out. I understand there is a chemical that detects carbon in cooling system. Seems that should be my next step to rule out hg. I also understand that heater plays a roll in cooling system but not sure how much it would effect water temp and pressure. Any suggestions would be appreciated
started overheating. I replaced heat sensor, radiator cap. Went to replace therm. but found it didn't have one. Did relace it with a non subaru therm. Didn't solve problem so replaced water pump. Also didn't solve problem. Current situation is that the top two hoses heat up and pressurize very quickly while the bottom stays cool and non pressurizes. At this point the engine is still cool to touch. I understand there is a hg problem with Subaru engines so I am getting the chemical that will show if there is carbon in your cooling system. I also understand that the heater core is a part of the cooling system. Don't know if it would cause this problem. Radiator seems like a logical fix except I ran water through it and it flowed smooth and clean. Any suggestions would be greatly appreciated.