Montana01

Hello,

I am new to the forum and have been doing research to try to figure out what is wrong with my truck. The truck has 116,500 miles on it and had about 111,000 on it when I bought it a few weeks ago prior to driving it from Alaska to Mississippi. I didn't notice anything wrong when I first picked it up. After hooking a light trailer to it and climbing hills or passing cars, it became apparent that something was wrong at high throttle settings under a load. It seemed that it was over downshifting and when it did, there was a rattling sound in the engine and the truck would actually slow down. At first, the engine light would flash, but then go out. Eventually it stayed on continuously. The truck sat for a couple of weeks while I was hunting moose and caribou. When I drove back to fairbanks after the hunt, the gentleman who sold the truck to me hooked up a scanner and said that there was a no. 3 cylinder misfire and that the plugs were probably fouled. I was on a tight timeline butchering and had him replace the plugs. He assured me that everything was good when he dropped it off. When I started it the next morning to start my drive back down to MS, the engine light was on and the truck was running rough. I took the truck into town and had a scanner hooked up which said one of the coils was bad but didn't specify. I found that the former owner had broken off the two-wire plug that connects to the no. 4 cylinder cop, and it was hanging on by a thread. I replaced the COP and the rough idle was gone, and the codes cleared. However, once on the road, the same issue under load came back.
I babied the truck 4400 miles back home, with no other option due to already being behind timeline. Enroute an exhause leak on the passenger side went from bad to worse. When I got to my brother's in MT, I pulled the passenger side exhaust manifold (which is a bear by the way) and replaced the two piece gasket set. Both original gaskets were blown out pretty bad. After putting it all back together there was still a minor exhaust leak between cylinders 3 and 4, but it was much better. I didn't have time to mess with it anymore and finished the drive to MS.
I limited myself to mid range throttle to keep the transmission from downshifting, the engine light from flashing, and the terrible racket that followed in the engine.
When I tested the codes at home there was a no. 1 and 3 cylinder misfire, and a o2 bank two fail (maybe because of the misfires?).
The truck seems to be getting progressively worse. It runs great at idle all the way through mid-throttle settings, but when you get on it, it sounds pretty nasty. Under a load at about 3000 rpms is when things go south. At idle, I have reved it up pretty good without anything unusual.
The former owner replaced the plugs and all 8 COPs about three years ago. He also had an injector stick open on him, which he had replaced. The injector, the misfire codes, and the blown exhaust manifold gasket have all been on the passenger side.
I swapped the COPs from cylinders 1 and 3 today to cylinders 5 and 6 and then pulled the negative battery cable to reset the codes. I took the truck out and it ran nasty, as expected, but I couldn't for the life of me get the engine light to come on or for it to pop any codes. That was weird because the engine light would flash every time I got on it before.
I did notice some pretty good oxidation on the electrode on the COP that I pulled out of the no. 1 cylinder, but not sure why no codes are popping now.
Anyway, any advice would be appreciated. One thing I'm thinking it might be is the Catalytic converter on the passenger side. Knowing that an injector was stuck open for some time on that side 3 years ago, coupled with the nasty rattling I'm hearing, and the fact that everything has been on that side of the engine is leading me down that path. However, I haven't seen any codes for the CC, nor have I noticed it looking different from the one on the other side (discolored from getting too hot).

I'm all ears.

Thanks

Montana01

One more thing...the plugs are autolite HT15s purchased at NAPA

firefighter1979

I don't know if this will help u any but my truck was doing the same thing except for the rattling noise from the motor its an 06 5.4 with 66,000 on it. It threw a code misfire #8 put new motocraft plug and excel coil and same problem but couldn't get it to throw a code again bit the bullet last night and changed the rest of the plugs and coils. Took it for a ride after and no skipping.

ellis4pa

Check all your plugs make sure the porcelain isn't cracked from installation, sounds like the guy was in a hurry breaking the cop and all, if you do need to change any, my preference is the Motorcraft 515 is the upgraded part i believe. You may want to pull a plug to check and see if anti seize was used, if not you'll want to get some on them before to long.
Driving it as far as you did with it misfiring would definitely have taken a serious toll on your catalytic converters.
As far as the rattling, how does it sound at idle? Does it tick or sound like a diesel at all? I'm asking because of the cam phaser issue, kinda makes me think the timing chain is loose, which would be from low oil pressure

ellis4pa

Just noticed your a 2006, i don't think the cam phasers were an issue in your year.
What oil filter is on it?

Montana01

Thanks for the reply. Yeah, it's possible it could be a couple of coils I guess. I doubt it is the plugs because they were just changed. I was hoping the codes would move to the cylinders I moved the suspect COPs to, but for some reason the codes aren't popping now.

Montana01

Thanks for the advice. I'll check the plugs tomorrow. In general, it sounds fine at idle. There is a bit of a tic but it is coming from the exhaust leak. It does act like the timing is off when it starts acting up under a load. However, it runs smooth at high rpms when in park. The oil pressure looks fine on the gauge (just above the midway mark).

lvledFX4

I have a 2004 doing the same thing.. I just changed my Solenoids and it got alot better. But the Misfire on Start-up is getting to me.. and I'm running money and patients...

CRF450

My 2006 just had a somewhat similair issue with the plugs. I already had new motorcraft plugs waiting to be put in, so I decided to wash out the engine, specifically the plug ports. The next day I drove the truck and it was fine, the day after that it It was running really rough like yours sounds. It was ideling really low and when driving it would hop/bounce and the engine would bog on acceleration. I told my dad about it, he's the best mechanic in town, and the first thing he said was "did you spray water on the engine recently?" He said I needed to replace the plugs AND boots, luckily that was my plan already. What happens is the moisture gets inside the boot and causes the spark to go down to the water build up and causes a line(forget what he called it) on the plug that makes it spark down it (passed where its supposed to). I replaced my plugs and boots and it fixed everything, you always replace the boots with the plugs.
Were the boots replaced with the plugs? I would suggest motorcraft plugs only.

Montana01

I just went out and pulled all the cops and plugs. I wanted to make sure nothing was broken when the previous owner installed the plugs and wanted to make sure he put anti-seize on the plugs. Everything looked pretty good. There was no anti-seize or dielectric grease on anything, so I applied both and reassembled. I also cleaned my MAF and replaced my air filter while I was in there. Truck is still doing the same thing. Gonna take it to a mechanic tomorrow and see if he can see any codes I'm not seeing. Still thinking it might be the catalytic converter. Some of the blades on the cops (electrode on the coil side) had some pretty good white build-up on them. Anyone know if that is normal? Those coils were replaced about 50,000 miles ago. I sprayed some MAF cleaner on them and put a little dielectric grease on them as well. Thanks.