2007 Ford Taurus studders/jerks at 45 mph *Fixed*

All I can say is thanks alot to everyone on this forum! I was starting to think my transmission was slipping and a huge repair bill was in store. Fix was coil pack and spark plug wires

The problem I was having was when I was driving in O/D everything seemed to work fine. HOWEVER if I was driving up a hill around 45MPH and only around this speed it would chug, or kinda jerk/studder, as if something is slipping or the engine is missing, the RPMs would stay the same, I could let off the gas and re apply and it would be fine. I was not getting any codes or engine lights, so I did not think it was a misfire.

After lots of reading on here and many people suggesting to buy a new coil pack and spark plugs/wires (plugs are newish, 6 months old), I went and did that. A hour or so later the fix was done. Its been a few days of driving now and the issue seems to be fixed. Not only that, the hesitation I would have sometimes when trying to accelerate is gone and it picks right up now.

Thanks alot guys! Love this forum and how everyone is so helpful! Just had to say thanks!


===================== UPDATE 2021 =================
So I thought The coil pack was the issue, however the problem came back, the spark plugs caused the same issue also.

On my 2007 Ford Taurus (Vulcan engine), I kept getting misfires when holding the throttle at a lower setting and going about 40-45 up a hill. If you push down on the accelerator, it would pick up just fine, it only seemed to miss at a lower range of throttle.

I changed out the coil pack and it went away for awhile. It returned about a year or so later. I finally found the solution to my misfires that I have been dealing with off and on for a year or so trying various things.

The problem was when my dad picked up some spark plugs for my vehicle the store mistakenly looked up and sold him "Champion 7963 Iridium" spark plugs, however these plugs are gaped at the
3.0L DOHC .052-.056 range which will cause a misfire at certain engine load and throttle position on the Vulcan.

After taking them out and noticing the gaps were almost .01 too big, I did some research and found out these were not the right gap or plug for the Vulcan engine, The Vulcan engine is gapped at 3.0L OHV .042- .046

I went and bought some Motocraft AGSF-32FM / Part# SP432 and VERY CAREFULLY checked the gaps on them. All of the plugs needed to be gaped slightly smaller. VERY CAREFULLY gap your plugs, they are easy damage because of the coating. Check a few youtube videos if you are not sure how to gap the coated ones,

After inserting the correct plugs and using the correct gaps my misfires are completely gone now. It's been a few months and my engine hasn't had any noticeable misfires anymore. Before the fix, it use to be almost every hill at speeds of around 40 if I didn't adjust the throttle to try and prevent it. Now it cruises up hills at any throttle position with out any issues.

hope this helps someone with their misfires.

CHECK YOUR PLUGS AND GAPS, TOO BIG OF A GAP CAN CAUSE MISFIRES...


EDIT: Spelling