Lurch while driving, transmission problem?

[Horace]

Hi! This is my first time posting here, though I've found a lot of useful knowledge while browsing previously.

I have a 2007 Ranger base model (2.3L 2WD, w/ Mazda M50D-R1 tranny I think, and w/ 50,000km) and lately I've been getting a lurch while driving. It's happened in 2nd, 3rd, 4th and 5th gear, and happens most when I'm driving at a constant speed. I can feel the truck slow very slightly, then lurch forward and continue on normally. I haven't seen any shift on the tach while this happens.

As for history, the problem started right after I had the truck in for an inspection on the front end (unrelated problem) and an oil change. The weather was cold (-20C) when it first started happening. I tried some gas-line anti-freeze as I thought maybe the fuel was having trouble getting to the engine. It seemed to stop for a while, but it has resumed. I've bought the truck new and have operated it in cold-weather conditions for it's lifetime so far and never had this problem so I don't think it's weather related. I also tried injector-cleaner but to no avail.

So, I'm wondering if something is going on in the drivetrain somewhere, perhaps the transmission. Thanks in advance for any advice you might have!

Luckily I'm still under the drivetrain warranty if something is up.

 

[strvger]

probably a long shot, but i'd take it to the dealer and let them run the codes to see if anything comes up. if not, the mechanics there should be able to duplicate the problem as it seems to be happening frequently for you. glad it's still under warranty for you. it honestly doesn't sound like your clutch is slipping or anything like that. doesn't sound like a fuel filter either. you would think that you'd be seeing a change in your rpm's if it were engine or transmission related.
good luck with this problem and welcome to TRS.

perhaps a brake sticking? still seems like it should bring the rpm's down if that's happening.

 

[adsm08]

Dirty MAF could cause that.

My recommendation would be to clean the MAF, replace the air and fuel filters if they haven't been done lately (Ford says every 30,000 miles on the fuel filter. I say they are cheap enough to do annually) and maybe a top engine cleaner. Seafoam up the EGR or 4x4 line.

If you had an auto, I'd say trans could be to blame. Since you have a manual I'd say it's unlikely a transmission issue.

 

[adsm08]

probably a long shot, but i'd take it to the dealer and let them run the codes to see if anything comes up.

Codes won't show anything, but Mode 6 data may show something. Mode 6 is the computer's record of things like evap leak and misfire rates. It's intended to help find things that are noticeable, but don't meet the threshold for setting codes.