Hi,

I am replacing the engine in a 2015 Ford Fusion 1.5. The engine I am taking out does not have the cylinder head temperature sensor. I am going to be installing a used engine with lower miles. I was wondering if the engine I purchase can have the cylinder head temperature sensor and I just don't plug it in due to the previous not having one? Or are there other manufacturing changes with the two engines that would prevent this?

Thanks

 

You will be fine without the sensor. The computer won't be affected by something it originally had no data from the begining.

 

Does the 1.5 with the cylinder head temp sensor still have an engine coolant temp sensor other than the one in the head?

 

There is usually a two wire sensor which supplies information to the computer and a one wire sensor which is used for the temperature gauge on the dash. You have to seek it out.

 

If you go by the logic of the manufacturer not requiring both sensors, how much they could save. They use both for a reason and to ignore the reasoning could leave you with problems you never anticipated..

Those sensors are there for a reason, not a good idea to ignore them.

The CHT sensor is there to initiate a special procedure to prevent engine damage if an overheat condition occurs..
The program initiates alternate injector operation so cyl don't fire thereby reducing engine temp.

 

I've swapped a few used Ford engines for sale, and in most cases, leaving the sensor unplugged won’t cause issues if the original engine didn’t use it. The main thing is to confirm that there aren't any other differences between the two engines, especially in the wiring harness or ECU.
Thumb is to try to match the replacement engine as closely as possible to the original. If the engine installing has a cylinder head temperature sensor and the original doesn’t, it’s usually fine to leave it unplugged if the rest of the system doesn’t need it.