Hesitation under hard acceleration

[mmaylock]

Recently I've started getting a hesitation while trying to pass or in any situation requiring hard acceleration. I can't tell if it's engine or drive train related. Has anyone experienced anything similar and do you know what might be causing it?

I'm considering taking it to the dealership but thought I'd check here first in hopes that it's something simple.

Thanks...

 

[Whack]

Recently I've started getting a hesitation while trying to pass or in any situation requiring hard acceleration. I can't tell if it's engine or drive train related. Has anyone experienced anything similar and do you know what might be causing it?

I'm considering taking it to the dealership but thought I'd check here first in hopes that it's something simple.

Thanks...

Year? Miles? Ever replace the plugs or Coils?

Whack

 

[GAINMOB]

check ur manifold for leaks...I had similar probs and both manifolds needed to be fixed

 

[mmaylock]

Year? Miles? Ever replace the plugs or Coils?

Whack

2007 - 120,000 miles. I replaced the plugs at 100,000 miles. Did not replace the coils.

 

[k9education]

2007 - 120,000 miles. I replaced the plugs at 100,000 miles. Did not replace the coils.

I guarantee that someone is planning on telling you that you must replace the coils, but they don't necessarily ever have to be replaced. Check them and if they look good, leave them alone.

 

[mmaylock]

I guarantee that someone is planning on telling you that you must replace the coils, but they don't necessarily ever have to be replaced. Check them and if they look good, leave them alone.

Will do. What am I looking for when inspecting them?

 

[Flexpedition]

Nothing to really check on a coil pack other than visually looking at it for external damage like it being cracked or melting, that its snugly in place, etc. If it was misfiring, even periodically there outta be a code present or pending. You didn't mention your check engine light being on, so we'll assume no code was thrown, but you could still use a code reader to see if anything is pending. What brand/model plugs did you install 20K ago? Did you check the gap on them? Air filter clean and changed regularly, using a stock housing? Can you see a dark ring of gunk around the throttle body plate? Have you ever cleaned the mass air flow sensor? Has transmission fluid ever been changed?

 

[GAINMOB]

I guarantee that someone is planning on telling you that you must replace the coils, but they don't necessarily ever have to be replaced. Check them and if they look good, leave them alone.

they are supposed to be replaced at 100K...so if u haven't done the 100K maintenance I would start there as it calls for plug and coils to be replaced along with other stuff

 

[JollyRoger]

Nothing to really check on a coil pack other than visually looking at it for external damage like it being cracked or melting, that its snugly in place, etc. If it was misfiring, even periodically there outta be a code present or pending. You didn't mention your check engine light being on, so we'll assume no code was thrown, but you could still use a code reader to see if anything is pending. What brand/model plugs did you install 20K ago? Did you check the gap on them? Air filter clean and changed regularly, using a stock housing? Can you see a dark ring of gunk around the throttle body plate? Have you ever cleaned the mass air flow sensor? Has transmission fluid ever been changed?

X2 on the above. Been down this road with both an '07 and '10. My list of things for hesitation/misfiring are:
Air Filter
Clean Mass Airflow Sensor
Clean throttlebody
Replace Spark Plugs
Replace COPs-no, you can't tell if they are bad by looking at them or metering them.

Those four things will typically result in noticeable improvement.

Somewhat related: I just replaced the VTC Solenoids on my '10 to take care of a wicked 'diesel-like' condition that happened occasionally when idling. The old ones were visibly bad. After replacement it not only eliminated this problem, but remarkably improved throttle response because it now instantly puts the valve timing where it needs to be when taking off from a stoplight. I can really tell the difference, and honestly didn't know the engine could run 'this good'. Really glad I did that, although it was a serious PITA!

Good luck!

 

[k9education]

I guarantee that someone is planning on telling you that you must replace the coils, but they don't necessarily ever have to be replaced. Check them and if they look good, leave them alone.

they are supposed to be replaced at 100K...so if u haven't done the 100K maintenance I would start there as it calls for plug and coils to be replaced along with other stuff

According to who? The COPs are not listed as a scheduled maintenance item in the owner's manual or the service manual for that matter. I know they're a common problem on some model year Expeditions, but if they're not throwing a code, showing any signs of damage (e.g. cracking), In the absence of a code or any visible sign of damage, I would leave them alone. If you're really convinced that one or more COPs is a problem though, test them (yes, they can be tested); don't just go replacing them for the heck of it. That's essentially what the stealerships do; just keep replacing stuff until the problem is resolved by dumb luck.