Acceleration issue (help/advise)

Been a while since I've been on here. But hello again!

2006 4.0 DCLB 85,000 miles 4x4.

The problem I am having is when I'm cruising city streets or highway. I will give it a little gas to speed up. It will usually drop a gear, or two depending, and I get this weird pulsation while it is going through the RPM. It seems to be more predominately in 3rd gear. But noticed it in 4th and sometime in 2nd. I've cleaned the throttle body and MAF already. From what I've read, it's coming time for the tune up. Is this something to look at, or could it be tranny related?

Any and all advise, I do thank you.

 

Have you ever had the transmission fluid changed/flushed?

 

Pulsation? Vibration? Grinding?

Does it happen between 25-40mph?

Could be a needle bearing issue perhaps. Try putting it into 4x4 4H while it's happening. If it goes away instantly it's probably the needle bearing. If it comes back as soon as you go back to 2H it's the needle bearing.

 

I had somewhat of the same issue a while back when I changed the spark plugs. Turned out to be a cracked spark plug. It would stutter around 40-50 mph when lightly giving it gas to accelerate.

 

Roughly 15k ago I had the tranny flushed. No grinding/vibration. It seems to be at any speed above 35+. Since living here in Germany, getting on the autobahn, when it drops down a gear and it starts to accelerate pretty quickly. Thats when I feel the pulse like its hunting for another gear but never does. There is a slight hesitation/pulse when getting to speeds from 40mph to 80mph. It doesn't feel like there is any power lost. As it starts to go up on the RPMs, I feel it less. But it does still exist.

I will try to get a video of it when/if I remember to do so. But the only way to describe it typing it out.

aaaaaaa.aaaaaaa.aaaaaaa.aaaaaa (accelerating) LOL

 

Inspect your spark plugs. If they are original, they have a lot of miles on them and the gap could be out of tolerance.

Also, take it to the Ring and get some videos!!!

 

Figured that would be the next step. According the book I have left by the previous owner that he did maintenance on. The spark plugs were changed by previous owner at 50k. Do not know what he used but could of been some cheap stuff.

Thank you for the replies.

 

I recommend Denso IKH20, if your engine is N/A. This is all assuming that the transmission is perfectly fine.

 

N/A yes. Ring....I don't know about that lol. The thing is crap for traction around turns. When I bought it, I thought the LSD would help on the streets. Not so good as it breaks loose almost on any turn with very little throttle.

 

At least cruise it for all of us dying to drive it!!!!! Ahhhhhh. Lol

 

HAHA. Understood. I will see what their schedule looks like for openings and try to plan a trip around that time.

 

Just get it running right first though. You're the man!

 

Of course. Number one goal at this point. Just put my order in with Amazon. Now to the waiting game of 2 weeks before I see them. Guess I'll have to pull out the beemer to get around for now.

 

So....Sorry for the very late update on this. After changing the plugs. It seemed to lighten the hesitation by a whole lot. I still kinda hear and feel it, but nothing like it was. Going to test the coil packs next when there is time available. Thing about Germany is they have quite Sunday. We tend to travel on Saturdays which makes it harder for me to make time for the truck. Kids are into a bunch of things after school. So yep, there's my time gone lol.