I am sort of in a bind withmy 2002 Chrysler Sebring limited 2.7 engine. I don’t know why this car is overheating.I had the motor replaced with a known working engine from anothercar. I had this mechanic which is not certified do the work, firstmistake. He told me the car was good to drive. So I drove it 16miles and car overheated and shutoff. When car was cooled of it startedagain. I let it run in the driveway at idle and 10 minutes or so itstarted to overheat and discharge water from the reserve tank. Idon't know if I blew a head gasket when I overheated the car. How can I checkthis? I am mechanically inclined so I have an understanding. Idid install a new thermostat with the spring side inside theengine which is correct? I do know the fans work when disconnected butwhen connected the fans don't run.



Here is the issues,

1. The fans do work only when disconnected from the sensor on the motor
2. The temp gauge in the car only reads halfway will not read past this point . The gauge never read hot. How can I fix this?
3. The A/C system is not working is there any correlation to the car overheating?
4. Is there a radiator cap on the radiator itself? I have pressure cap on my reserve tank is this my radiator cap?

 

1. Disconnecting the sensor should cause the fans to come on. It's a fail-safe feature that turns on the fans if the computer (which controls the fan operation) loses input from the sensor. The fans are not supposed to work all the time.
2. That's what it's supposed to read.
3. Probably not. There are lots of possibilities for the A/C not working. Get it checked by somebody who knows what he is doing.
4. No. Yes.

From what you have written, I'm not sure your car is overheating. You say that the gauge never goes past the center. The first thing I would do is replace the pressure cap. If that is bad it could allow the system to boil over without overheating. It's a lot cheaper than replacing a head gasket and might do the job. Make sure you have the correct antifreeze in the correct dilution in there.
If you still think the car is overheating but not showing it on the gauge, try replacing the sending unit.
If you still suspect the head gasket(s), get a compression check to verify that before you spend big money replacing them.

 

When the ac is on the fans will come on if the dont U prob have a fan issue. Been know to be bad. But unless u plan on testing things out not just replacing take it to some one with the tools and knowledge to test items out no guessing.