2007 Fusion low coolant temperature OBD code

I have an '07 Ford Fusion with 94,000 miles. The check engine light came on a couple of days ago, so I took it to a shop to have them pull the codes on it. The code that came up said the coolant was not reaching the proper temperature, and the mechanic told me the thermostat should probably be replaced.
Two questions:

  1. Should I go ahead and get it done, or wait and see if the check engine light comes back on? I usually only drive the vehicle about 10 miles a day, and it’s all city driving.
  2. What kind of cost should I be looking at? He said it would be a system flush, replacing the coolant and thermostat (which they would get from a dealer), and it would cost $270.

I replaced my thermostat for a similar code. Price is probably a bought right, though I did it myself. If you have a timing belt and water pump replacement due, do them all together.

Replace the thermostat. If the coolant doesn’t reach the proper operating temperature, the computer stays in the open loop mode. This then causes the engine to use more gas.


It’s only 6 years old, so the coolant shouldn’t be gunky or with a lot of crud. The long-life coolants they use are typically good for a bit longer. I’m nervous about doing a flush. A chemical flush should not be done, and a simple rinse with clean water is all that is needed. All else sounds good.

Change the thermostat as Tester said. This is even more important since you drive on a lot of short trips. With your driving style, especially in winter, the oil doesn’t get hot enough to burn off all the condensation and other volatiles that collect in it, and carbon can accumulate in the cylinders as well. With the thermostat not allowing it to warm up all the way, you’re making it worse.

I’d also give the car a nice long highway run at least once a week if you can to get the crud out of it.