2000 5.4. 145K. I've owned the truck since brand new, and know all the history.

injectors flushed, and plugs replaced at 100K

My problem is it has an annoying little misfire at low RPMS. Usually when it does this, I can hear what sounds like old school "pinging" sounds like it comes from the drivers side. 90% of the time, if I put the pedal to the floor, and it downshifts and revs up, the problem goes away. However lately it seems to be getting worse. NO check engine light. I did put a scanner on it, about a year ago, and it didn't find anything. It doesn't do it all the time either. I can go a few hundred miles, and nothing, then all the sudden it does.

FYI, I don't drive the truck much. I doubt the fuel filter has 10K miles on it, but I plan to change it to rule it out.

Any advice before I take it in?

thanks
-Shane

 

Update.

replaced fuel filter. the fuel from the filter was NASTY! Truck runs much better now. Hauled my enclosed trailer with my sons go kart racing equipment for a few days back and forth to the track. Noticeable difference in power, and only one time for a split second did I notice this miss on the interstate. It usually happens when driving about 55-65mph.

crossing my fingers its fixed, and if it does happen again, I will change the filter one more time, just to rule it out. Can't believe how bad the fuel in the filter was with only 10K miles on it.

 

Plenum is known for the EGR port clogging. May not be enough to throw a CEL yet, but a restricted EGR system will cause pinging. It's worth removing and cleaning. You should expect to find very hard carbon build-up. Probably some YouTube videos floating out there on it. I've done it personally and it was a pain to clean out those holes, but made a huge difference. This one was completely clogged and throwing a P0401 code.

Other thing to look for is a small vacuum leak. First thing I'd look at is the PCV hose. If it's collapsed or rotting, replace it.

Last thing that is of concern is a fuel filter that was clogged after only 10k. May want to pull the tank and inspect for rust inside. That will quickly clog a fuel filter and the strainer. Only real fix is to replace the tank.

All of this assumes that your plugs and are not due for a change, and you don't have a weak coil or check engine light.

There are of course other things that could cause this, but I'd look at the things above.

 

thought I would bump this thread up again.

after replacing the fuel filter, the truck ran great for about 3 weeks, then went back to having the annoying miss, although it rarely pings anymore.

I noticed the valley full of antifreeze, and lurching out the back, so I am currently in the middle of replacing the intake. I decided to do the whole intake, instead of just gaskets. I could actually see the antifreeze dripping from the bottom of the intake while the motor was running. Also doing the RS valve cover gasket while its off. Plugs / boots are recent, so not messing with them. My neighbor is ford service advisor, and said he had 3 trucks in with the same issues as mine (leaking antifreeze, and intermittent miss) all getting new intake gaskets. All the hoses looked good, and everything is disassembled, and cleaned up, ready to be put back together tonight. Hopefully it takes care of my issues.

truck has 147 on the clock, so I can't complain to much about putting some money in it.

 

New intake back on, and truck is up, and running again.

I cleaned the throttle body, egr port, MAF, injectors, and coils up as best I could while everything was apart. Ran like azz for about 90 seconds, and blew some nasty smoke, but cleared up, and ran great, no miss, drove it around the block (still need to change oil) and seemed to run great, but I need to put some miles on it to be sure. No leaks.

I bought the dorman intake. I was a little concerned about some of the mounting tabs, namely the throttle linkage bracket. Screwing into plastic isn't a real assuring way of doing it, but we shall see the original intake had metal inserts for machine screws to attach too.

I did unbolt the crossover from the old intake, and sure enough it was cracked/broke on the passenger side. I am assuming that is where the majority of the leaking antifreeze came from. Seems to be common problem.

Took me about 6 hours all said and done. I was taking my time, and could easily do it in 3-4 the next time around. Love this truck, just wish I could get ahead of the rust. For a truck that sees 5K/year, I think its still got a few years in it. I suspect I might have a weak coil, but planning to run it, and see if I still have the miss, if so, it will get new coils this winter as well.

 

Good Job! Congratulations!

 

I just helped do an intake today and same deal the crossover was cracked broken. I also replaced the orings in the heater tube and put a hose over the connection and clamped it just to be safe..

 

yea I didn't do the heater tube, only cause I didn't know about it, and didn't have the o rings while it was apart. I did check out the clearance with the new intake, and I think worst case I could still get to it, with out removing the intake again. Won't be easy, but I think it can be done.

Put a few more miles on her yesterday. Still no miss, or leaks. Keeping fingers crossed.

 

no way you get at that with the intake on. No way.

 

care to explain why? I'm not disagreeing with you, but the dorman intake has quite a bit more clearance then the OEM did. I can put my entire hand on the pipe, even with the alternator on there. What am I missing?

Like I said, mine isn't leaking anyway, but you never know.

 

Just getting to the bolts on the back of the block then getting your hands down there to remove the o-rings. Clamping a hose? forget it. no way you get at the clamps.

 

gotcha. I wasn't sure how the pipe came apart (at the back of the block) so that makes sense.

Well, guess I'll just hope it doesn't leak. If it does, at least I have some practice on removing the intake. LOL. FYI I could easily get the clamp on the pipe, and tighten with a swivel, I'm pretty sure. The new intake is actually quite a bit easier to get to the actual pipe itself. But I see what you are saying about the back of the block. That would be a PITA.

 

You must have small hands! There might be a little more room but I dont see that much space!