Volvo: 97 Volvo 850 GLT, volvo 850 glt, accelerator pedal

Question
My check engine light came on and the car was difficult to start.  My husband finally got the car started by keeping his foot on the accelerator pedal and pumping the gas.  We drove to the mechanic and when I turned off the ignition I noticed that the engine fan kept running for about 5 minutes.  Very odd.  

The mechanic replaced the temperature sensor and the car drove fine for two days.  Then the same thing happened again (although the car was easy to start this time) - the Check Engine light came on and the fan ran for 5 minutes after the ignition was shut off.  

I brought the car back and the mechanic said some oil (or fluid) dripped on the sensor wire which had caused the problem.  He fixed that and the car ran well for one day but the same thing happened again (check engine light - fan blowing)!  

I don't know what to do at this point.  Should I bring it somewhere else?  Can something else be causing the problem?

Answer
Mary,
Go to a shop that knows the Volvo. They have the proper tools to repair and read codes in your car. The teck you when to possibly read codes and had a temp sensor code and replaced it, but the sensor was not the problem and is still running cold. The thermostat maybe at fault. I see many broken t/stats and that will set a temp sensor code.