jhlankford

This has been going on for several weeks now. 5.4L 3V, while driving or sometimes at idle there will be a miss in the engine. No check engine light. It might be a mile down the road before it happens, might be 10 miles or more. On occassions there are consecutive misses, but not as a rule. I bought a coil, and rotated the coil around the engine to every cylinder. It made no difference. I changed the recently changed fuel filter anyway. As a last resort, I took it to the Ford dealer here. They put the portable computer on it, drove it, and immediately told me the #3 cylinder was spiking and that it was the coil and perhaps a plug if it had fowled due to the coil. I asked specifically if they were sure that was the problem, because I had told them what I had done to try to find the problem. They said they were sure, so I gave them the go ahead. $238, and the problem remains. Now, they say to bring it back the day after Thanksgiving because they are trying to get cars out that have to travel (we'll get to your service rework later). I really need some help here. Anyone have a clue here? Seems as though the dealer doesn't.

roc73

My 05 5.4L has been doing this since I bought it in 07. To me, the thing sounds like a diesel sometimes. I took it to the Ford garage and they told me nothing is wrong and it is just the way Fords run. It just doesn't sound right and I don't hear others sounding like mine. It still runs okay, but I don't know how else they run since this is my first one and it has been doing it since I bought it.

fx4_soldier

my dad has a 99 explorere that sounds like a mini diesel lol but theres nothing wrong with his truck, my 05 fx4 does the same thing never bothered me and i dont really feel like im losing power, truth be told i wanna change the plugs but ive heard they break so ill take it in when i get some extra cash.

jhlankford

That IS normal because of the sorry cam sensors. I am not talking about the sound of the engine, this is a hard miss, like the engine stops for a half second, no power for a blink. Although, it is most certainly only one cylinder, not all.

Trapper

I'd let the dealer try again to figure it out but if they don't or can't, I'd suggest replacing the PCV on it. Most likely the dealer will tell you it is not a replaceable unit- that's not true and it does require service. Some of these units have been malfunctioning and yields a miss especially at cylinder #3. Yours should be a heated unit and is hard wired to a connector. Look for it in the intake manifold if you want to replace it yourself. It's a bolt in unit. Use only a Motorcraft unit. Other brands may not be specifically tuned for your engine and can create even more problems.

rok73, go to the following link and look at Episode 22 concerning the VCT on your engine. It will explain to you the differences in sound of the injector tick and a cam phaser that has gone bad. The video is Ford training vids for their techs so yer getting it straight from the horses mouth.
http://www.flatratetech.com/index.php?categoryid=4

You must have high speed internet to watch- not for dialup.

04SilverF150

Is that PCV you are talking about the one on the drivers side, or the passenger's? Reason I am asking is that I have what looks to be factory on the drivers side and a piece of rubber hose on the passengers (I bot it used, obviously)...

jbhill

crappy 2 piece spark plugs sound like the culprit.

roc73

Thanks Trapper. I think mine sounds like the faulty valve lash adjuster. Will driving it like this do any harm to the engine or is it just annoying?