Engine overheating
Asked by Chasity May 19, 2019 at 08:28 AM about the 2002 Ford Focus SE
Question type: Maintenance & Repair
Hello, my vehicle is running hot.
Within the past 3 days I have
replaced the plugs and wires,
thermostat and it housing had AC
recharged and car is still running
hot. But if I turn the AC or the heat
on the car cools down.
2 Answers
Sounds like your engine cooling fan may not be working? When you switch on the AC the cooling fan automatically kicks on. That may be why the engine temp comes down. Next time you are driving (keep the AC off) and see the engine getting hot, park it (leave engine running) and open the hood, if fan is not running then either the engine coolant temp sensor is not working or fan controller is not working. PS: Some cars have TWO fans, one for primary engine cooling, and a second fan for the AC. If that is the case then check your primary fan is working.
You also wrote "when I turn the AC or the HEAT on car cools down". Turning on the heater can provide a meager amount of engine cooling as well, since it acts as a mini radiator, again that just means the engine radiator is not doing it's job which can still be the cooling fans, but also check your coolant flow.