My Subaru 2.5 is over heating only when driving. I've bled the cooling system, replaced the thermostat, top and bottom hoses, radiator cap and flush the radiator but still over heat.Cooling fan are working. I let the car run sitting in the driveway for over a hour and it went to normal temp with fans running but didn't over heat at all but when I drove it for about 20 minutes it pushed the coolant into the overflow and temp went to the hot mark. Can anyone tell me what to do next. I also did a compression check which was normal range.... 

Edited October 2, 20178 yr by fiveaces

electric fans working ?    If so your probably looking at head gaskets.

Definitely head gaskets. 1000%.

 

GD

Thanks guys I'll do another compression check and go from there.

Compression test will show nothing. That's not how these gaskets fail. Waste of time. Replace the head gaskets. You don't need any further testing. 

 

GD

All '96- '99 Subaru J25D engines will have headgasket failure (usually by 150K miles). We recently bought our '98 Legacy GT at only 94K miles and they already were replaced at 91K miles, so it can vary.

Coolant blowing into the overflow tank. 99% head gasket.

^ + bubbles and oily residue.

 

HG,

Edited October 8, 20178 yr by wtdash