2000 Forester
Temp gauge hits red during light stop and go traffic or highway driving within 20 minutes, does not hit red just from idling.
Temp gauge rises with coolant temp viewed on scan tool.
Thermostat opens at correct temp (lower radiator hose gets hot), has new Fail-Safe thermostat.
Fans turn on at 95 C.
When the gauge hits red the temp is 100 C, highest temp I saw was 101 C, temp stayed between 90 C and 95 C at first but once it hit 100 C it wouldn't drop unless it sat and idled for about 10 minutes. I didn't push it too much because I didn't want to damage anything, A/C off and heater off, ambient temp 80 F. Cooling system was burped when thermostat was replaced and then a week or two later burped again and I got more air out of it.
Burping procedure: with spill proof funnel on radiator, run engine until thermostat opens, let engine run and occasionally rev to about 3000 rpm until no more bubbles are seen. I waited about 15 minutes after thermostat opened each time.
Head gaskets have been recently replaced.
I don't trust the dash gauge, I don't think 101 C should be red-line but it does seem high, I haven't been able to find a maximum temp spec or normal operating range. I haven't worked on Subarus much and this is my first time messing with a Subaru cooling system. I haven't yet blown out the radiator fins, that's on the schedule this weekend. Is this a normal operating temp? At what what temp is engine damage likely to occur? I'm not even sure if I actually have a problem or not with a coolant temp of 101 C.
