Engine Performance problem
2000 Ford Expedition V8 Two Wheel Drive Automatic 213538 miles
i'm not the original owner so i'm not sure what kind of thermostat was in the vechile. I recently replaced my thermostat and now when the vechicle gets to the new hotter operating tempature the engine is running rough when in gear. I first thought radiator fluid on the plugs or on the coil, but enough time has passed, (two days) and the truck has been driven a few times without getting to the full tempature, that any fluid should have evaporated. Next I thought head gasket but no oil in the radiator fluid or radistor fluid in the oil. Please help
Hi kmcgee, Welcome to 2carpros and TY forthe donation
If its actually running rough due to engine temperature get it block and pressure tested-if not check and test the following idle air control valve, EGR and PCV valves -throttle position sensor and mass airflow sensor, fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), dirty fuel injectors, low fuel pressure, or contaminated fuel.