Howdy. First post, but I promise, I searched. I found one thread from 2007 that mentioned an identical problem, but no solution posted.
Last October my mother bought a 2000 Outback (2.5, AT). The previous owner had paperwork for a timing belt, and said the head gaskets were done but had no paperwork. My brother took it to a shop for an inspection and they say it's obvious to them that it was done at some point within the last couple years, along with a new radiator. So we're driving the car, and it never heats up. The CEL is on, so I get it scanned, and there's a code for a bad thermostat. I've never heard of a code for a thermostat, but whatever. My mother doesn't drive much, so we went through the winter with what I presumed was a thermostat stuck open. It's a PNW winter, so it's not that cold.
A couple weeks ago I got a new 170 degree thermostat from AutoZone and put it in. As it turns out, the old thermostat was busted up so there was just a metal frame in there, not the spring and closure flap, so basically no thermostat. The coolant looked good when I drained it, but I put new in anyway. I ran the car a bit, the gauge was right in the middle at the 9 o'clock position, let it cool, topped off the system and the reservoir, and everything seemed to be fine. Even the CEL went off as soon as I put the thermostat in. However, the car has a weird overheating problem now. I can run it on the highway no problem, or in town no problem, but if I'm driving at highway speeds, then get off an exit and my speed drops to city traffic speeds, the temperature gauge spikes almost to the red. It will cool down after a couple minutes, but it makes me nervous and certainly doesn't seem normal.
I've been driving the car for 3 weeks, sometimes with the A/C on, and the temperature only spikes in that one specific situation. It doesn't lose any coolant, the heat works fine, both radiator fans work, and the radiator doesn't have any cold spots. I'm at a total loss. Only thing I can figure is maybe a sensor that's not turning the fans on at the proper temperature, but that's a total guess on my part.
Any suggestions would be appreciated.
Last October my mother bought a 2000 Outback (2.5, AT). The previous owner had paperwork for a timing belt, and said the head gaskets were done but had no paperwork. My brother took it to a shop for an inspection and they say it's obvious to them that it was done at some point within the last couple years, along with a new radiator. So we're driving the car, and it never heats up. The CEL is on, so I get it scanned, and there's a code for a bad thermostat. I've never heard of a code for a thermostat, but whatever. My mother doesn't drive much, so we went through the winter with what I presumed was a thermostat stuck open. It's a PNW winter, so it's not that cold.
A couple weeks ago I got a new 170 degree thermostat from AutoZone and put it in. As it turns out, the old thermostat was busted up so there was just a metal frame in there, not the spring and closure flap, so basically no thermostat. The coolant looked good when I drained it, but I put new in anyway. I ran the car a bit, the gauge was right in the middle at the 9 o'clock position, let it cool, topped off the system and the reservoir, and everything seemed to be fine. Even the CEL went off as soon as I put the thermostat in. However, the car has a weird overheating problem now. I can run it on the highway no problem, or in town no problem, but if I'm driving at highway speeds, then get off an exit and my speed drops to city traffic speeds, the temperature gauge spikes almost to the red. It will cool down after a couple minutes, but it makes me nervous and certainly doesn't seem normal.
I've been driving the car for 3 weeks, sometimes with the A/C on, and the temperature only spikes in that one specific situation. It doesn't lose any coolant, the heat works fine, both radiator fans work, and the radiator doesn't have any cold spots. I'm at a total loss. Only thing I can figure is maybe a sensor that's not turning the fans on at the proper temperature, but that's a total guess on my part.
Any suggestions would be appreciated.
