I'm having issues with my 2001 lariat shifting on the interstate. The truck runs fine around town, but when I get on the interstate and get up to speed, usually above 55mph and when I'm going uphill, the truck gets more of a lunge/shake for a second like it's having trouble getting into gear. Kind of like a rough shift. It happens once I've reached speed and then try to maintain it by giving it a little gas. It's intermittent and doesn't happen all the time. There aren't any codes being thrown. I took it to the shop yesterday and they mentioned a possible shift solenoid or maybe a fuel issue. I'm taking it back in Monday but wanted to get some input as to what y'all think it may be. Thanks for the input.

 

How many miles are on the truck? Sounds like COPs to me. Have you ever changed the plugs and COPs?

 

It's at 138k. I replaced one of the plugs/packs after it went out back in November on cylinder 1.

 

Geenerally when on coil fails the other 7 go to. 1 at a time for months/ years. Sound like another one went out. I'd just replace them all..

 

Have you ever flushed your transmission fluid?

 

Are the rest of the plugs and coils original? If so, the plugs are WAY overdue for replacement.

 

Plugs are not original, but are not brand new. Previous owner had replaced them. However 7 of the coils are original to my knowledge. And this was my original thought as well. The more I have thought about it, fuel is out of the question and the symptoms seem more like the precursors I had when the first one went. Any suggestions on plugs to run? Thanks again for the replies!

 

Motorcraft plugs, Motorcraft or Visteon cops.

 

X2, run as much motor craft you can on the engine. Best stuff for it.

 

Thanks guys!! Going under the knife Monday.

 

Motorcraft plugs:

4.6: SP493
5.4: SP479

COPs:

http://www.ebay.com/itm/1998-2008-LINCOLN-TOWN-CAR-IGNITION-COIL-VISTEON-BRAND-NEW-ALL-8-PCS-/370944224459?pt=Motors_Car_Truck_Parts_Accessories&hash=item565dffaccb&vxp=mtr
Do not use antiseize on the plugs, torque them to 28 ft/lb.

 

Could be torque converter too. Vibration under load. Ignition, fuel, tranny, U-joints, center support bearing

 

My 2003 F250 4X4 Superduty (89000 miles)has vibration and power loss when shifting from 2nd to 3rd only and occasionally. It must be under load as when climbing mountains or hills. It does not matter if the overdrive is on or off. It must be hot for it to happen and does not seem to do it if you shift it manually. However, I tend to ease off the throttle when manually shifting. It only happens for 2-3 seconds and then recovers. It has been getting worse for the last 10000 miles. I was wondering about a U joint, center support bearing myself, or transfer case.

 

My guess would be an ignition coil or possibly a spark plug.