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Jared D
Jared D, ASE Certified Technician
Category: Ford
Satisfied Customers: 1777
Experience:  Shop Supervisor at County Fleet
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I have a 2007 ford expedition, after vehicle is warm while

Customer Question

I have a 2007 ford expedition, after vehicle is warm while driving it has this hesitation, feels like I'm going over rumble strips on side of the road. The hesitation comes and goes as we drive.
Submitted: 1 year ago.
Category: Ford
Expert:  Jared D replied 1 year ago.

I have seen the 5.4l engine on the 2007 expedition misfire with no accompanying trouble codes (check engine light). Sometimes it will hesitate and shudder for miles with no code set.

When was the last tune up on the vehicle (spark plugs and boots)?

Your symptoms could also be a restricted fuel filter; when was it last replaced?

Customer: replied 1 year ago.
did plugs within last year, never fuel filter, also replaced all plug coils
Customer: replied 1 year ago.
my mechanic seems to feel its a drive/ tran issue although cannot pinpoint it
Customer: replied 1 year ago.
definitely no engine light or code set
Customer: replied 1 year ago.
had to replace tension bar and belt , then problem seemed to start?
Expert:  Jared D replied 1 year ago.

A hesitation from the drivetrain? Does it feel like the transmission is slipping?

Does is change based on pushing the gas more or less?

Customer: replied 1 year ago.
doesn't seem to, just happens randomly but always when engine has warmed up and at lower speeds 35-50
Expert:  Jared D replied 1 year ago.

Did the mechanic use Motorcraft plugs? We have a fleet of about 1200 fords, 200 of them are the 5.4l engine. If you use anything other than Motorcraft plugs it will misfire, just as you describe.

Rarely do we get them in with slipping transmissions; they usually just go out completely when they go.

Expert:  Jared D replied 1 year ago.

Is it most noticeable when you are just barely on the gas, almost coasting?

Customer: replied 1 year ago.
not sure I will have to ck.? But wouldn't they misfire immediately ? or would they break down over time
Customer: replied 1 year ago.
no, more noticeable when pushing on gas.... never when coasting
Customer: replied 1 year ago.
I am no mechanic but have worked on vehicles for 30 years, I feel it is a engine issue more than a drivetrain issue. but with that said that while I am talking to a professional
Expert:  Jared D replied 1 year ago.

Then I would definitely say it's the plugs.

No, they don't misfire right away. They usually start acting up about 5,000-10,000 miles after replacement.

You also have to fill the coil boots with dielectric grease- this sounds unusually, but it is essential to keep them from misfiring down the road.

Customer: replied 1 year ago.
ok that's seems about the timetable on mileage since we replaced plugs .
just to clarify it feels like a vibration/hesitation when it happens very noticeable to
Customer: replied 1 year ago.
what if the are motorcraft plugs we used ?
Customer: replied 1 year ago.
also what if we used after market coils, will that have same effect not using motorcraft like the plugs
Expert:  Jared D replied 1 year ago.

If they are motorcraft plugs then you may just have to drive it until they set a code. You will also want to inspect the boots for signs of spark jump, which would be caused by no dielectric grease when they were changed.

Aftermarket coils aren't as big of a deal. Most of the brands you can get will perform as well as the factory brand.

Expert:  Jared D replied 1 year ago.

Please let me know if you need additional information.

Expert:  Jared D replied 1 year ago.

Let me know if you need additional information.

Please don't forget to rate. They don't pay us if we don't get a positive rating.