wastroupe

Hey guys, I finally upgraded from my 1998 F150 5.4 to a 2008 F150 Lariat supercrew 4x4 5.4 3v with 83k miles.




I've had the truck about a week and have already noticed an issue. During light to moderate acceleration, I notice a slight hiccup in the 30-40 mph range. This "hiccup" is best described as a quarter second dead spot in the throttle. At times, I have noticed an additional hiccup between 20-30 mph that does the same thing. Occasionaly, I will also feel a slight vibration on take off. It's important to note that if I acelerate at a quicker pace or really get on it, I can't feel the issue. I have also had a tough time replicating the issue when I deactivated overdrive. Not to say it wouldn't do it, but I really couldn't tell if it was doing it. Also, I've noticed that when I sreally tep on it, It takes maybe a second to catch before accelerating. (From what I've read, that's common for 5.4s though, just thought I'd note it)
I have had spark plug and coil pack issues out of my 1998 model, but they felt different than what this truck is doing. Is it possible that this is the same issue but is manifesting itself differently? I breifly spoke with my mechanic and he seems to think it sounds like a torque converter issue. He checked for codes and none were showing or pending in the computer. Transmission shifts good. Fluid is a pinkish orange color, and there are no metal shavings on the oil dipstick.
Any input is appreciated! I'd like to get it running like a top!

SCORGE

Sounds like a mild misfire to me. Did you by chance notice if the CEL was flashing whenever this shudder occurred?

wastroupe

I should also point out, I have notices sometimes (not all the time) it idles slightly rough. Just a little subtle shake

wastroupe

Thanks for the reply. The engine light hasn't flashed at all when this happens. It very well be a misfire, I just have never felt one that mild and assumed that a code would be stored if it was. I hope it's something that simple! Lol!

SCORGE

Unless it throws a code, best chance to catch it would be with a scanner.
Probably about time for plugs and coils (boots and springs if you don't want to replace the whole ignition coil)

wastroupe

Probably will have that done anyways. Won't hurt anything!

SCORGE

Note: When this truck has mild misfires like this, it definitely resembles a TC locking/unlocking over and over. I thought the same when it first happened to me. Eventually started throwing a flashing CEL and I replaced an ignition coil which solved the problem (as previously stated, you can just replace boots and springs as the actual Ignition coil may not be the issue). Eventually did the first spark plug change and replaced the remaining coils shortly after. This was around...100k.

GoldyGopher

It almost sounds like the same problem I had after having my differential fluid changed (07 Lariat Screw). The shop didn't add enough of the additive, and the truck would shudder just after changing gears at 25-35mph (ish). Had I not just had the fluid changed, my first thought would have been with the ignition system as well. I took it back in, and they added more of the additive, and she is smooth as cat poop on a linolium floor.

wastroupe

Quick update, I started to notice the truck would sometimes shift a little hard into 4th. I took the truck by my mechanic and he rode with me. I was able to replicate the original issue. He told me it felt like something in the transmission. He said that my fluid smelled a little burned to him, but it was still a pinkish orange color. He said he would service the transmission and adjust the bands. The truck has 83k miles so I'm not too worried about a major transmission problem. He said he was fairly certain the servicing would correct the issue. I'm also going to have him put a new set of coils and plugs on as well. I'll keep everyone updated

wastroupe

I appreciate the reply. When I take the truck to be serviced, I'll have him check that fluid as well. Thanks for the input!