Difficult Cold Start/ Normal Hot Start My 2009 Challenger RT 5.7 developed a new issue....... stumbling cold start when it used to fire almost immediately. Once warm, normal starting. Did a little research..... read a note that said ‘since it’s temperature related, start with the ECT sensor’. Swapped it out this morning...... problem solved. The OEM sensor exterior was made entirely of plastic. The new MOPAR replacement part number is 05149077AB. ($41.35 with tax). The new part is made of brass, complete with thread sealant on the threads. Ten minute job. Hardest part was figuring out the release for the wire connector. There was a tell-tale sign of part failure. When I removed the wire connector, there was a tiny amount of coolant inside the end of the sensor.
Great location! Looking at the engine....sensor is on the right of the water pump, under the air inlet to the throttle body. ( from the drivers seat, that would be the left, drivers side. I have a cold air snorkel so it was a piece of cake to change. Snapping off the engine cover provided all the room I needed. Stock air inlet may need to be removed. Also..... I had no codes set in the PCM for this issue. DEFINITELY do this repair on a COLD engine. You’ll lose a little coolant but if you’re quick, you won’t lose much. Just add a little to the reservoir.
