'06 4.6 Bucking and Kicking :(

[Savage Exploder]

Good evening. Ive been searching around the forums for quite awhile, and I haven't quite come across anything similar to what I'm seeing on my 06 Explorer 4.6 with 54K miles. When I am on the highway in 6th gear, with my foot lightly on the throttle (feels like just enough to open the throttle blade), and I give slight pedal pressure to accelerate, it seems to buck and kick. If I give it enough throttle to downshift, it takes off just fine. No CEL's at the moment. Is this a common occurrence, that is most likely caused by coils/plugs, or am I in for something more invasive?

I've owned the vehicle for 3 days, and have an appointment with my mechanic on Monday to go over the truck with a fine toothed comb (dealership gave me 60 day warranty) to make a list of things to be fixed.

So far very happy with my new 4th Gen versus my old 3rd Gen.

Thanks in advance, and I apologize if I've missed something simple in my earlier searches. I try not to be the new guy, who doesn't do their homework before posting.

 

[Bill MacLeod]

If you don't know the service history of the vehicle, then plugs as well as fuel and air filter is where I would start. Observing what parts (brand or part #) may indicate whether or not they have ever been replaced. 54k on a 2006 is very low mileage so it is possible that little service has ever been done.
What you describe sounds like misfire (worn plugs) to me. Don't believe the 100k hype.

 

[Tech By Trade]

Plugs and coils. Probably looking at around a grand to get them replaced in a shop and none break off in the heads. 2 if you are in Canada.

 

[tripplec]

Its all guess work until you scan get the codes from it.

 

[boominXplorer]

Put a set of Motorcraft plugs in and go from there. Since its not a constant miss I figure your coils are just fine.

 

[tripplec]

Yeah if you or they are going to replace some plugs have them do them all even if you have to pay for it. Then its done. Changing one ore two when the others are old will lead to problems later. If not very soon.

 

[Savage Exploder]

So I brought it to my mechanic today... he scanned it and there was no misfire history within the last driving cycle. Should I still proceed with a plug change?

 

[tripplec]

Well was it doing it when you brought it to him.

NOTE: If you change the plug use the new specified plugs and not something else. I believe they've switch to a one piece plug now and if he has the tool to get out difficult ones its up to you. Millage wise its not due but something is causing it so its a matter of time whether you do it now or later. Without codes there is no way of being sure what else to look at. Thought your dealer was taking care of it!!!

Anyway it may only act up if hot and underload. Not enough info...

 

[Savage Exploder]

Thanks for the replies so far. I really appreciate the input.

It is only acting this way under load in 6th gear, but a down shift into 5th seems to clear it. I will add that acceleration seems somewhat flat, lending to this being caused by an ignition issue. As I am reading, the ECU needs to really see something problematic before it will present a misfire code, so that might also explain why there aren't any codes.

I brought it to my mechanic, simply to compile a list of items that I am going to have the dealership I bought it from address, before the 60 day warranty runs out. Just got off the phone from making the service appointment with the dealership for next Monday morning. I am going to get them to replace the plugs under the warranty, as it is truly impacting drivability.

 

[tripplec]

Yes IMO they should start there. Be sure they are clear its in 6th under load. Any mechanic will or should realize something is breaking down. EG Plugs and or coil. Plugs are old as likely original.

Good luck

 

[Savage Exploder]

Much appreciated. I will report back.

 

[jlmust]

I have an 07 spot trac limited with the 4.6 and I've dealt with your exact issue since I purchased it 6 years ago with 100000 km. I had ford do the plugs and it still did it. No codes ever showed up, they road scanned it and found what cylinder was acting up and changed the coils accordingly. 6 years now and I still get the same miss fire kicking in 6 th gears. Changing the coils only seems to last a 6 months to a years and it starts again. I have 200000km now and have been sinking money into it steady again. 1st Drive shaft, 2nd LF wheel bearing, 2nd LR wheel bearing, 2nd radiator. Dual heater control now has cold on one side and heat on the other side. 1st exhaust now needs to be changed. Stereo cd works perfect but has no lights in it. From Ontario Canada Took off the running boards last year due to calcium aluminium blue corrosion. Rocker panels and cab corners are showing rust now. It's been and still is a endless money pit.

 

[Explorer_PL]

The sparkplugs and coils on those v8's can cause all kind of issues. People replaced torque converters, and even transmissions for nothing.
Ford was trying to sell me new tranny for $ 5,000 since I was getting a communication error between ECU and tranny, and they said my mechatronic was bad so they recommended the whole tranny since back then the car had already over 200k miles. Luckily, I did not fall for it, and kept googling that issue, and it turned out to be coils on one side. I was surprised since I just put there new accel yellow coils, but those engines seem to like motorcraft only ones. I installed new Motorcraft coils, and the tranny still pulls strong at 247k miles.

 

[Savage Exploder]

Appreciate all the input folks. Really happy I joined this community

 

[jlmust]

Not sure why i still love my truck but you definitely need deep pockets to own one.

 

[tripplec]

LOL
For some that was true and was also said about the Jeep Grand Cherokee's 2002-2004 vintage which I had. I did not find it that bad though. Front suspension needed a major overhaul but the powertrain ran to near 300k km before I sold it and got something newer. Still running strong a mileage was great for the beast.

As was for the Cherokee the Explorer parts are all robust and IMO not likely to wear out as in many Lighter body SUV's as they are true CUV highway machines. As for the Sports Trac I don't personally see the advantage. A very small box pretending to be a pickup. When my son got his first vehicle the 02 Sport Explorer he looked at them but opted for the closed in 2 door being single, 4 wasn't a must have. It was bigger inside than my Cherokee. The newer 09 is considerably bigger now. All your cargo is out of the weather. We have trailer should additional space of stuff need be hauled.

 

[joel_s]

My vote is for coils. Had the exact same problem and if it did it long enough to throw a code to isolate which one, replacing the coil for that cyl has, so far, always fixed it...knock on wood.

 

[tripplec]

Yeah, but in this case no code yet. Dealer not likely to swap em all out. I'd still start with plugs myself. Who knows after 10 years on them plugs there could be tons of carbon build up etc (OLD PLUGS). Either it was used for a lot of very short drives or sat a lot of the time. Either way the plugs can't be that great or ruled out. There isn't a way as in the old wired ignition systems you could scope and see the firing voltage on a screen on the big 8's. Now with COP its invisible and likely more than a misfire anyway with that symptom Carbon could be the issue. Pre-ignition anyone...or is that too old a cause for most of you.

 

[joel_s]

10 years! Yikes. I missed that from the OP. Yeah, I replace my plugs every 100k like a good boy, but for some reason cyl 1 (iirc) goes through coils.

Oh, and OP, don't just "drive through" the bucking and kicking, you can trash your tranny that way. Ask me how I know.

 

[Savage Exploder]

Just checked the carfax to see if plugs had been replaced at some point within the 11 years, but as expected, no such luck. I am leaning toward replacing all of the plugs regardless of what the dealer says for all the same reasons stated above. I really wish this darn thing would throw a code!

Just a little added detail....
the bucking and kicking is occuring at 2500-2800ish RPM, and clears once it has revved past that, but still only in 6th gear.