Hi - My 2006 H6 3.0 Outback with 95,000 miles on it, overheats when going highway speeds up long grades. I bought the car from the local Subaru Dealer who had replaced the blown head gaskets
on this engine before selling it. The reason for replacement was that the engine had overheated and blown the headgaskets. I have checked everything possible, including replaced the radiator, T-Stat, etc. There is no coolant loss, no bubbles coming in to the overflow tank, and passes the coolant system pressure test. The Subaru mechanic is at a loss as to why its running hot going uphill. If you have any ideas, they would be greatly appreciated.
JA: Have you checked the coolant? Have you noticed any leaking?
Customer: yes - no leaking
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: replaced T-Stat, radiator, pressure test
JA: Anything else you think the mechanic should know?
Customer: I think Ive shared all I know