Hey all- Have a 2001 Subaru Legacy GT, 5 speed manual, 194,000 miles.
A few months ago, I started noticing that my cooling fans are running more often. Even when it is cold out and the temperatture gauge was at normal temperature. The fans would turn on, and just keep running. Obviously, they would turn off when I shut the car off, but if the car is on, they will stay on. However, I found a trick to get them to turn off. If I am in neutral, and I race the engine up to around 3000 RPM’s or so for about 10 seconds, and let it come back down to idle speed, the fans are now off. Works almost every time, not just a coincidence.
I know my car, and this has never done this before. I know it is not normal. I have replaced the following- thermostat, coolant temperature sensor, flushed the system, changed the fan relays, and most recently, I put a brand new Subaru radiator in. All of this, and the issue is still there. I am beginning to wonder if it is the water pump. Coolant not circulating fast enough, so the fans come on to help cool down, but when I race the engine, the water pump works harder circulating coolant faster? Also recently, the temp gauge starts to climb going up long steep grades. If I pull over and race the engine, the temp gauge drops almost immediately back to normal. The pump is not leaking or making any noise, so I’m not sure if it could go bad any other way.
Before I go ahead and but a $140 pump, I’d like to hear some other possibilities.