I have a 2002 FX4 with the 5.4. Lately, my truck has began to shake while in overdrive. Anytime it is in overdrive, and I try to accelerate, it starts to shake, but quits if I give it enough gas to make it downshift. I thought that overdrive was the only gear it was acting up in, but today I got on it from a dead stop, and it kinda hesitated before it wound on up. I orginally thought it was the transmission, but it acts like it is being starved of fuel. Also, if I pull up to a stop light, the truck will sometimes jerk when it's idling, or just idle rough. No codes or sensors are being thrown either. Any ideas on what it could be, or what I could try to correct this? Thanks.

 

Have you changed your air filter, or cleaned/oiled it lately? Over-oiling an air filter can gunk up the MAFS and cause problems like those

 

COP's would be my guess. The spark plugs have a coil on them that act as the spark plug wires. (COP = Coil Over Plug). If it throws a code, read it and it will tell you a misfire on what cylinder and thats the one you change. They are like 60 bucks from autozone. Good luck

 

I just put a new K & N in it about 8,000 miles ago. Can it be a COP and a code not be thrown?

 

I don't know anything about COPS, but a cheap and easy thing to try would be to get a can of Electrac contact cleaner (or something like that). It's a metal pressureized can with red, white, and black on it. It says it is for cleaning electronics. The point is that it doesn't leave any residue. Then pull your MAF sensor out and spray all the sensors good and plenty. Let it dry for a minute or two, and pop it back in. I would also reset the PCM by unplugging the battery for 20 minutes while you clean the sensor.

 

Check this thread out -

https://www.f150online.com/forums/sh...d.php?t=280844

 

I would say it's the coil as well my wife's 02 expedition has done the same thing along with two other expeditions that we have had. According to Ford you are suppose to change them out at 90k miles.

 

There is no instruction by Ford to replace the coils at 90K or at any other interval. I wonder who told you that.

The OP has a misfire. This is an axtraordinarily common problem and object of discussion on these forums. There is nothing wrong with his MAF sensor and there is no indication it needs attention.

jbrew and I have both posted several times about how to find the fault when the CEL is not yet on. SEARCHing for "misfire" will locate these threads and instructions.

Steve

 

So I should replace all 8 coils while I'm at it? Also, should I go ahead and change my spark plugs as well?

 

That's up to you , it's a good idea since COP's are now cheap to replace. I replaced mine @ 165,000. If you replace them all you equalize your ignition therefore keeping the integrity in tact. IMO that's important with COP systems in these motors and also beneficial as far as performance. You'll maintain your motors full potential as far as power this way..

You must replace them right - greasing is a very very important part of the process..

Swapping out the plugs for new is also a good idea - use Motorcraft Plugs - there the failsafe plugs for these motors...

Good Luck