strange issue with 07 V8, no diagnostic lights

[absentx]

So I am having a weird issue with my 2007 Eddie Bauer V8. This just started about a week ago.

Basically when I am driving, I get random "hesitations" and I can't tell if it is the engine misfiring or some type of hesitation or problem with the transmission trying to change gears.

I will be going at speed and you feel like a "bump...bump..bump..........bump" and usually at that point I give it a bit more gas to "drive through the problem" which usually works.

I have tried a fresh tank of gas and some fuel injector cleaner. The problem is I am not getting any check engine or flashing O/D off lights!

Any ideas on what could be wrong? I am not sure where I should take it because a mechanic will have to reproduce the problem and have no codes to go on.

 

[edwx]

I wouldn't take it anywhere just yet. It's probably not doing the same thing for several drive cycles in a row, so it's not setting a DTC. Maybe try a different gas station for a while and try a good fuel system cleaner. The problem might go away. Have you ever changed the plugs?

 

[TowingExplorer]

Going with edwx's suggestion, I would also question the spark plugs.

My '06 V8 with 72k on it has a similar hesitation at very minor throttle when just cruising. I suspect a misfire from old plugs and will change them to find out.

I also tried some Chevron injector cleaner and had no luck.

 

[boominXplorer]

sounds like a miss fire under light load, either plugs or one of the coils is taking a crap

 

[absentx]

All I can tell you about the plugs is they are the updated type that wont break off...so that's good...Yeah maybe I will give em a change and see if that happens.

 

[TowingExplorer]

All I can tell you about the plugs is they are the updated type that wont break off...so that's good...Yeah maybe I will give em a change and see if that happens.

Were all '07+ the update plugs or does that mean yours have been changed?

If yours have been changed, at what mileage?

 

[absentx]

I just know that the plugs on my vehicle are the updated type...which I think you are saying all 07's are?

I bought the truck at 57k and now have 66k, I have not changed the plugs nor am I aware of the last time they were changed, so they certainly could be due for a change.

 

[BigBlockRanger]

Wifey's 2007 Mountaineer developed a intermittent miss just like the OP's problem with no check engine light. Pulled a coil pack and the plug boot looked like this.

I pulled all the coil pack/plug boots and squirted in some fresh dielectric grease (available at auto parts stores). Reinstalled and the miss was cured. I did this over a year ago and the problem has not recurred. Factory plugs/boots/coils, 79k miles.

 

[03 Explorer XLT]

I had the same problem. Slight acceleration on the highway would do it. It was one of the coil pack boots. New boot, no more problem.

The updated plugs went into engines built after November 2007. Mine was built one month too soon.

 

[absentx]

any way to nail down what plug or coil it could be on your own or best to just take it in?

Still no lights, but the problem was seemingly less apparent today.

 

[03 Explorer XLT]

You can pull the coils off and inspect the boots. Look for cracks, burn marks, anything that doesn't look like the others. Put some dielectric grease on the inside of the boots when you put them back on. If they're in decent shape, the grease alone might be good enough.

 

[mounted]

My 06 did the same thing. Replaced the plugs and it runs like new again. I had 95k on mine when I swapped 'em.