2011 Expedition XLT poor acceleration

[Burt1631]

My expedition will not accelerate, driving is fine but when I need to accelerate it has a long pause then "slowly" start to increase power. I had new cam phasers, new timing chains, sensors..etc. It's been in the Ford dealer since July 23, 2025 and they can't find the problem. I guess the mechanics are too tech savvy! I assume they have used all their equipment to test the fuel pump, injectors COPs, plugs and everything else. Now what. Any comments, guesses or what the hells, would be appreciated. Thanks in advance.

 

[99WhiteC5Coupe]

My expedition will not accelerate, driving is fine but when I need to accelerate it has a long pause then "slowly" start to increase power. I had new cam phasers, new timing chains, sensors..etc. It's been in the Ford dealer since July 23, 2025 and they can't find the problem. I guess the mechanics are too tech savvy! I assume they have used all their equipment to test the fuel pump, injectors COPs, plugs and everything else. Now what. Any comments, guesses or what the hells, would be appreciated. Thanks in advance.

What dealer in Cincinnati or the Tri-State?

 

[Burt1631]

Croin Ford in Middletown

 

[DieselMonk]

Does it have any codes? What about fuel pressure, MAF, vacuum in the fuel tank, etc.?

 

[Burt1631]

Friday I have a meeting with the dealer to find out what they have done, tested or replaced.

 

[GlennSullivan]

First question, did it have the power problem BEFORE they just did all the engine work? If not, something was done wrong during the work.

If the power problem was there before, Have they looked into plugged cats? Have they driven the vehicle and watched live data while driving.

 

[ChaLug]

My expedition will not accelerate, driving is fine but when I need to accelerate it has a long pause then "slowly" start to increase power. I had new cam phasers, new timing chains, sensors..etc. It's been in the Ford dealer since July 23, 2025 and they can't find the problem. I guess the mechanics are too tech savvy! I assume they have used all their equipment to test the fuel pump, injectors COPs, plugs and everything else. Now what. Any comments, guesses or what the hells, would be appreciated. Thanks in advance.

I had a similar issue on my 2015 Platinum. It would "bog" at take-off and also when cornering. It was like a hesitation. After much research I found one suggestion that worked; I changed the air filter. I didn't see in your post that they had looked at that because it seems so trivial, but the Ford mechanics I go to at the dealer here never looked at mine. After changing the air filter, my Expy responded when I wanted to accelerate.

 

[Burt1631]

Does it have any codes? What about fuel pressure, MAF, vacuum in the fuel tank, etc.?

Talked with the Ford mechanic today, no codes, fuel pressure fine but he stated the timing is retarting vs advancing when accelerating.

 

[Burt1631]

First question, did it have the power problem BEFORE they just did all the engine work? If not, something was done wrong during the work.

If the power problem was there before, Have they looked into plugged cats? Have they driven the vehicle and watched live data while driving.

Parts were replaced because of the same problem. Mechanic stated vats were not plugged and he did drive it and data reflecting the timing retarting vs advancing when accelerating.

 

[Burt1631]

I had a similar issue on my 2015 Platinum. It would "bog" at take-off and also when cornering. It was like a hesitation. After much research I found one suggestion that worked; I changed the air filter. I didn't see in your post that they had looked at that because it seems so trivial, but the Ford mechanics I go to at the dealer here never looked at mine. After changing the air filter, my Expy responded when I wanted to accelerate.

That was changed 3K ago, but I will check it out.

 

[Burt1631]

Ford mechanic does not know why it's not accelerating properly. He stated the timing is "retarting" vs advancing upon acceleration. He stated it may be the PCM or oxy sensors. He wanted to changed those as a way to troubleshoot. I said if it doesn't work I'm not paying for parts or labor. Ford couldn't agree with that.

 

[GlennSullivan]

Talked with the Ford mechanic today, no codes, fuel pressure fine but he stated the timing is retarting vs advancing when accelerating.

Have they logged or live observed knock sensor operation during acceleration? A faulty knock sensor “seeing” knock would def retard timing and not throw a code as that is a regular function of that subsystem.

 

[DieselMonk]

Retarding instead of advancing? That will certainly put a stop to your go! No missfires or knock or whatever codes? Baah… timing chain skipped a tooth or stretched, something wrong with the phasers maybe?

 

[Fastcar]

Retarding instead of advancing? That will certainly put a stop to your go! No missfires or knock or whatever codes? Baah… timing chain skipped a tooth or stretched, something wrong with the phasers maybe?

Ya think???? Christ sounds like at their last job these so called "techs" were asking "would you like lettuce and tomato with your cheeseburger?" Sounds like they are a bunch of parts replacement specialists wanting to throw more parts at it. Tell them you want a copy of every RO reflecting everything that has been done to it thus far. You might want to ask to see a written diagnosis and how it was arrived at. Damn! the next thing will be to rotate the tires.

 

[Burt1631]

Ford mechanic does not know why it's not accelerating properly. He stated the timing is "retarting" vs advancing upon acceleration. He stated it may be the PCM or oxy sensors. He wanted to changed those as a way to troubleshoot. I said if it doesn't work I'm not paying for parts or labor. Ford couldn't agree with that.

I've written to Ford asking for assistance.....yeah, I know, but it's worth a try.

 

[BigOleFordFan]

Damn! the next thing will be to rotate the tires.

Yea, but don't forget to replace the running boards & Mud flaps while they're at it, as those being faulty have been known to severely "retard" the acceleration/response times, hahaha

And they might as well check that the mirrors are functioning properly too....

j/k !

 

[Burt1631]

My expedition will not accelerate, driving is fine but when I need to accelerate it has a long pause then "slowly" start to increase power. I had new cam phasers, new timing chains, sensors..etc. It's been in the Ford dealer since July 23, 2025 and they can't find the problem. I guess the mechanics are too tech savvy! I assume they have used all their equipment to test the fuel pump, injectors COPs, plugs and everything else. Now what. Any comments, guesses or what the hells, would be appreciated. Thanks in advance.

Turned out it was the dreaded cam phasers and cat converters, the phasers replacement kit, a bolt broke and had to be redone. Also a cam and cam rollers were replaced. Cost a lot but cheaper than 60 months of payments. There were no codes during all of this