Q: Transmission shifting issue, rough idle

asked by on January 27, 2018

My car shifts harshly with a jarring kind of forward motion almost like leaping ahead. only on the 1-2 shift, the 2-3 shift and downshifts from 5-2/1. No codes are stored fluid has been changed with Motorcraft FNR5 fluid and the filter has been changed with a motorcraft filter. My car also idles poorly. it hovers around 650 but vibrates throughout the car mostly in the steering wheel and seats and only when in gear and at a complete stop. I had a valve gover gasket leak into the plug wells that i changed myself so i changed all 4 plugs because 3/4 were submerged in oil but i did not change or test the coil packs, i'd figured theyd be okay could both of my issues be related to this? all 3 of my motor mounts are OEM and new. besides the passenger side is a used OEM but i may change it out as well.

My car has 64000 miles.
My car has an automatic transmission.

If the engine is not running properly this can cause the transmission to shift poorly sometimes. I would recommend resolving the issue with the engine running poorly before having any transmission repairs performed. It is also possible that the amount that was not replaced could be causing the issue since faulty engine and transmission mounts can cause severe vibrations and also harsh shifts.

You may have a bad coil pack if it was covered in oil and shorted out into the spark plug hole. This may affect the transmission shifting if the engine is misfiring. If the engine light is coming on then it may set a misfire code to the cylinder that has a bad coil otherwise you may need to replace one at a time until it is found.

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