5.4 help lease
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Post Fiend
Joined: Jan 2009
Posts: 6,521
Likes: 11
From: Greenwood, SC
5.4 help lease
I posted this topic in the expedition forum but I'm also asking y'all to give me advice too.
Hi all, our 2008 expedition has 105,000 miles on it, been completely reliable and pleasant to drive. Recently it has become very sluggish.
Down on power
Starts and runs normally
No other symptoms, temps all normal
Running same gas as always
Consistent maintenance, fresh air filter, frequent oil changes
It's just sluggish, noticeable when going 35 and wanting to accelerate to 55, takes a long time, high rpms just don't have the oooomph it used to.
So, what ages and makes this motor lose power? I need to bring it back to the way it should be but without any codes thrown or any noises/smells/symptoms it's hard for me to know what to do.
Please give me your ideas/experiences.
__________________
2011 F250 6.7 4X4 Lariat Ultimate FX4 3.55 ELock
Polk Audio component speakers, AFE Stage 7 intake
Sho Me Strobes, Shocker XL Horns, BakFlipG2
2 Kicker 10" subs, Rockford Fosgate amp
Ride-Rite air bags, VIAIR #10007 onboard air, AFE DPF back exhaust, power slot rotors/EBC pads, Nitto Trail Grapplers M/T 295/55 R20! Transfer-Flow 50 gal tank
Hi all, our 2008 expedition has 105,000 miles on it, been completely reliable and pleasant to drive. Recently it has become very sluggish.
Down on power
Starts and runs normally
No other symptoms, temps all normal
Running same gas as always
Consistent maintenance, fresh air filter, frequent oil changes
It's just sluggish, noticeable when going 35 and wanting to accelerate to 55, takes a long time, high rpms just don't have the oooomph it used to.
So, what ages and makes this motor lose power? I need to bring it back to the way it should be but without any codes thrown or any noises/smells/symptoms it's hard for me to know what to do.
Please give me your ideas/experiences.
__________________
2011 F250 6.7 4X4 Lariat Ultimate FX4 3.55 ELock
Polk Audio component speakers, AFE Stage 7 intake
Sho Me Strobes, Shocker XL Horns, BakFlipG2
2 Kicker 10" subs, Rockford Fosgate amp
Ride-Rite air bags, VIAIR #10007 onboard air, AFE DPF back exhaust, power slot rotors/EBC pads, Nitto Trail Grapplers M/T 295/55 R20! Transfer-Flow 50 gal tank
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 23,174
Likes: 1,679
From: Stephensville WI
These engines will last an easy 500,000 miles. Some have been documented to last over 1.2 million miles.
Something is wrong with your engine. Start with the basics. Was the engine tuned up at 100,000 miles?
What is your fuel pressure? When was the fuel filter last changed?
Something is wrong with your engine. Start with the basics. Was the engine tuned up at 100,000 miles?
What is your fuel pressure? When was the fuel filter last changed?
Thread Starter
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Post Fiend
Joined: Jan 2009
Posts: 6,521
Likes: 11
From: Greenwood, SC
Ok, will check the fuel system. Admittedly, I don't know where the fuel filter is. I will find out though.
Would new spark plugs help? I didn't put new ones on yet. Thanks for the ideas.
Would new spark plugs help? I didn't put new ones on yet. Thanks for the ideas.
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 23,174
Likes: 1,679
From: Stephensville WI
Yes. New spark plugs would help. Your spark plugs should have been changed at 90,000 miles, along with your fuel filter.
Continued driving like this could result in you burning up your catalytic converters.
Continued driving like this could result in you burning up your catalytic converters.
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 23,174
Likes: 1,679
From: Stephensville WI
Super Moderator
Joined: Aug 2003
Posts: 25,479
Likes: 742
From: Isanti, MN
All good suggestions, but I'm pretty confident many of these things would cause trouble codes that would set the CEL. For example a plugged fuel filter would cause a lean condition. The spark plugs definitely need to be changed if they're original, but I don't think they can cause lack of power without misfiring.
If there are no other symptoms it almost seems like you have an obstructed intake or exhaust system. Just a WAG, but your converters may be on the way out. Hope not, they're not cheap!
If there are no other symptoms it almost seems like you have an obstructed intake or exhaust system. Just a WAG, but your converters may be on the way out. Hope not, they're not cheap!
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Hotshot
Joined: Jul 2013
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a. carbon build up
b. spark plug status
c. how's the fuel filter
d. when does your area switch to modified gas ....is this what you are sensing?
b. spark plug status
c. how's the fuel filter
d. when does your area switch to modified gas ....is this what you are sensing?
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Post Fiend
Joined: Jan 2009
Posts: 6,521
Likes: 11
From: Greenwood, SC
Thanks for all the input gents.
Mpg is a solid 16 around town all the time, but my wife drives it and it may as well be my grandmother with the way she babies it. She's a careful moderate driver with our kids in the seats.
I went ahead and got new plugs, just got into it tonight to see what I'm in for. Turns out I'm kind of in trouble. The guy at the parts counter sold me new boots for the new plugs, and now that I took one apart I get it, seems like a good idea.
Anyway, it's running on 7 cylinders right now because I can't get the spring to seat on the top of the plug. How do I seat that spring properly? I think I will figure it out in the morning but dang, it's not easy is it?
Mpg is a solid 16 around town all the time, but my wife drives it and it may as well be my grandmother with the way she babies it. She's a careful moderate driver with our kids in the seats.
I went ahead and got new plugs, just got into it tonight to see what I'm in for. Turns out I'm kind of in trouble. The guy at the parts counter sold me new boots for the new plugs, and now that I took one apart I get it, seems like a good idea.
Anyway, it's running on 7 cylinders right now because I can't get the spring to seat on the top of the plug. How do I seat that spring properly? I think I will figure it out in the morning but dang, it's not easy is it?
Postmaster
Joined: Apr 2008
Posts: 4,724
Likes: 4
From: Rogersville, TN
X2. You can take an O2 sensor out and see if it runs any better. If the cat is clogged up this will allow the exhaust to escape before getting to the cats and choking the engine off.
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