Engine runs rough?

you are going in right direction see pic to check VCT actuators maybe the problem. there is a TSB for later model ford trucks for this, but shown is test and what to check. then check fuel pressure for misfire if you still have them as well as doing freeze frame to read sensors to see if one low or out of spec. See picture.

We can forego the common stuff since I am sure you have done that already. Let me shift your thinking in a different direction. Look if your engine has an EGR system with eight individual tubes running to the cylinders. Some of these systems operate by allowing a measured amount of exhaust gas flow, then that is supposed to divide up equally among all eight cylinders. Over time one or two tubes become blocked with carbon. Those cylinders run especially fine because they get only fresh air. The other cylinders get too much EGR, and eventually misfire. As this progresses, there may be only one or two cylinders still getting EGR flow, but they are getting that which should have gone to other cylinders. It is the cylinders with clear EGR tubes that misfire, and those with blocked tubes run okay. Since EGR shouldn't take place at idle or low speeds, the misfires do not show up there.

If I am off-base, consider re-posting your question, as this one has gone "off the list", and none of the other experts will see it or have a chance to respond.

I replaced the spark plugs in my truck and now it's running bad and shaking when I drive at a continuous speed and when idling. It ran fine before I replaced them. Any suggestions on what it might be?

make sure they are set right and firing order is correct it may run rough for a bit until the computer gets used to them, especially with your mileage. This guide can help us

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Thanks I appreciate the advice. About how long will it take for the computer to get use to them?

It shouldn't take long, as long as they are the correct plugs. If it still doesn't straighten out then something else is wrong with it. If the check engine light is on scan for codes and check for a vacuum leak.

They have been in there for about a week. I thought that maybe one of my coil packs was causing it. I actually put those in a year ago without changing my plugs because it was acting up, it has been running fine untill I changed the plugs. I ordered some which ended up being the wrong ones after they said they would fit. Do you think that my coil packs could be it or would a vacuum leak more likely be it?

Could be either, have it scanned for codes. Most auto parts stores does it for free. Then check the plug wire and coil pack for resistance. The plug wire may have been damaged on removal.

a little bit back my truck started to stumble at lower rpm.. ran the diagnostics and said cylinder 3 was mis-firing or not firing... I changed the plugs and wires and still no fix. I asked a mechanic for some info.. He said to stick a screw driver on the plug to see if there was spark... there was spark at all the plugs.. It is also a SINGLE coil pack.. I preformed the same tests at each port of the coil pack.. When I gave him the results of my tests.. He stated its not the coil pack.. Before I go spend more money that I dont have. I don't think the cylinder it self is shot because it prefoms pretty normal at a higher rpm's... any suggestions or tips that I might try would be very very appreciated. Thanks

When you say single coil pack, do you mean 1 per cylender? Also, have you checked the compression in that cylender? Has the mechanic checked to see if there is an injector pulse at that cylender? If you only have one coil for all cylenders, have you checked the spark plug wire? If not, at night with the lights off, start the engine and spray a mist of water on that plug wire to see it there is an arc coming from it.

Let me know what you find.

Washed engine on Tuesday it sate until Thursday drove Thursday running fine drove32 miles ran fine came home sate for awile drove it to the lake started running rough checked oil ther was oil on the stick when I sipped it and checked it again none on stick put 4quarts in also Tuesday I removed the battery cable to clean it off also added to the over flow bottle could it be spark plugs coils

I have seen many times when the coil packs are damaged when the engines are cleaned. However, you should have a check engine light to indicate which cylinder is affected. Tell me, you added 4 quarts of oil. Did that fill the engine? Are there any noises from the engine?

Not unusual just the phasers which are lifters which is common for that year idles rough in drive and reverse I had a similar problem no light and for replaced the plugs ther was oil on the stick when I pulled it out put it back in no oil showed up added 4 quarts takes 5 .5 ford said ther was a proble with the phasers lifters that year many friends have the same diseal sound

Yes it filled to full line oil stick

Just the usal phaser sound like a disel truck yes 4q filled it I had bad plugs before my light never came on took it to ford and they replaced them

i added some Restore to my truck, and almost immediately the check engine light came on and it started running really crappy. it has a rough idle, and almost no power. i was slowing down for a stop sign and the rpms started fluctuating rapidly. once the engine's warm, it doesn't do it as bad or as much, but still acts up occasionally. any idea what could cause this?

With so many treatments on the market, if you don't mind me asking: What is "Restore?" Is it gas, oil, or something else?

I'm not sure why the light isn't coming on if there is a misfire. My first guess, however, is a coil pack.

"With so many treatments on the market, if you don't mind me asking: What is "Restore?" Is it gas, oil, or something else?"

it's an oil treatment that is supposed to restore engine compression by adhering and "filling in" the cracks and wear marks inside the cylinders. it has nothing to do with the fuel/emissions system, yet it seems to have triggered something in the engine...unless it's a coincidence. my wife filled up on thursday, and there was just under 3/4 tank when i dumped it in. i would think that if it was a fuel problem it would have happened prior to the additive. don't know, i'm stumped!

Have you checked it for codes? Even if the light isn't on, it may still leave a code in memory. I would be leaning towards a mass air flow sensor, but it may be something else. I know autozone will scan codes for free, but don't buy anything until you post back. It could be something entirely different.

[quote:7119141848="flexy5"]Have you checked it for codes? Even if the light isn't on, it may still leave a code in memory. I would be leaning towards a mass air flow sensor, but it may be something else. I know autozone will scan codes for free, but don't buy anything until you post back. It could be something entirely different.[/quote:7119141848]

my buddy has a code reader and i plugged it in tonight. it was the cam/timing. i cleared the code and the light went out. the wife says it's been running fine the last couple days. maybe the restore built up on the sensor and caused a faulty code or something...no clue. we'll see what happens, but it seems to be alright now. thanks for the reply/advice.

I had my oil changed,and it ran good for a couple of days. Then it started to run very rough (cutting back, hesitation, and low idling). The oill needle went to zero and my truck wouldn't hardly go. I checked the oil and it was empty, and smoke was coming out of the dipstick. iput two quarts of oil in, but it didn't do any good. The next day I went to crank it and it was still running rough, and the oil needle still would not move.

your going to need more the two quarts! fill it up with cheap oil and perform a oil pressure test. let me know what you find.

If it's a 5.4L, you'll need 7-qts w/filter.
Check your oil drain plug and oil filter area for leaks.
Also check around your radiator area for leaks, sometimes there is an oil cooling eliment in or out of the radiator.

after started and went to leave truck ruff running. Went to town check engine light came on went to part store. Codes are P0301. P0316. P0171

the 300 codes are a misfire which are very hard to diagnose and best left to a pro so yo udon't buy unnecessary parts. bu t you also have a lean code which 171 so check fuel pressure with a gauge auto parts rent it. that may be setting the other codes. see link. then if fuel pressure is ok then have a pro check the other. Auto parts will try to sell you plug wires, plugs etc which may not be the problem.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I took truck to garage today they did a test and it was the coil pack in cylinder 1 running good now.. they said must of threw all the other codes because of coil pack.. thanks for help

they took the coil pack off put on cyl 2 and it misfired.. so put new one in for $40.00