pas

I''l try to keep this short. Was driving the other day (2003 4.6l) on some rough dug up highway. Truck starts shaking violently. I'm thinking its the road. Get on smooth pavement and still shaking. I'm thinking I blew out a couple of tires. I get out on side of interstate all tires good. Its the engine. I drive truck to next exit which is 2 miles away cant even get over 25-30. I get off interstate start taking back roads to try to get truck home. A couple miles down the road there is finally an area to pull off. I put truck in park and rev it. Doesn't feel too bad but still shaking a little. My point is the truck was definitely starting to run better. I go to the closest autozone and have them run scanner. At this point they are telling me there are 4 misfires. I get the truck home and clear the computer. Run scan again and only cylinder 6 is misfiring. Now what ever happened on interstate yes I believe 4 cylinders went out but as I drove the truck it did get better where now its more believable that cylinder 6 is the only problem left. I changed plug and coil pack on 6. Still running rough. I even changed coil pack with another new one I had. I always keep them around for this truck. Still getting a bad miss. I tested fuel injector it has correct ohms. Has this ever happened to anyone? Any ideas what to look at? Also when I pulled plug it was very tight. It wasn't replaced that long ago (autolite double platinum). I was nervous it had been cross threaded but there were no shavings on the threads. Had a little difficulty getting it out. I couldn't get new motorcraft in to easily with fuel hose so I did use a little antiseize to get it in and started, seems to have gone in fine by hand and then tightened with ratchet. Trucks got about 197k on it. I bought it with 110k 10 years ago.

Has this happened to anyone? Any ideas on what to do?

Thanks

Jbrew

Autolite = Big mistake as heat range can go to hell at any given from install. Considered a knock-off. Should of used Motorcraft, they are manufactured to Ford spec.

No details how you determined it was cylinder 6 soo...

Never us a-sieze for a 3-4 thread plug chamber...it's doesn't figure out right with 30 % torque reduction. In-turn the plugs either get severely over torqued, cracking the porcelain or at the very least, compromise the seal. It is also VERY EASY to screw the thread chamber up...rounding the threads. All bad news when incorporating anti seize with these particular heads.

More problems than you know at this point is my guess. Might want to come here first and inquire before pulling maintenance on a modular....for a heads up.

white89gt

As Brew said, you're going to be chasing your tail unless you do that tune-up correctly. Anti-seize and Autolites are both not good on these motors. I use Autolite's on my Escape, and it's fine. Modulars are Motorcraft or bust.

You need to put Motorcraft plugs in, 28 ft lbs DRY so you don't mess with the torque value. Motorcraft plugs are nickel plated to act as an anti-seize (rust inhibitor).

pas

Scanner is saying cylinder 6. I replaced the autolite that was in there with motorcraft. I think I used the one autolite double platinum once as replacement because that was recommended on some board and the correct motorcraft wasn't available where ever I was buying the plug.The whole truck is not on autolites. I don't usually use antiseize but motorcraft wasn't going in all the way(it was very tight just like autolite was tight coming out and I didnt want to force it) with fuel hose as starter so I used a little antiseize for lubrication and it seems to have gone in fine and bottomed out just by hand without ratchet and then I tightened with ratchet

mbb

Change your fuel filter.

Then change your sparkplugs to motorcraft

Funny story
Once i thought my truck was riding kind of rough on interstate for a week or so...
But ran fine
I left it at airport for trip out of town for 2 days.
Got back 11 pm, started it, it idled a bit rough
Slowly drove to parking exit ,expecting it to clear up, it didnt
On interstate on way home, it barely ran, no acceleration, shaking , check engine light , then cel blinking. Wtf, it ran fine last time driven. Barely go 50.

Managed to barely get home at midnight, 22 mi from airport.

Looked at it next day....random misfire code, and misfires on 2 cyl.
Ran better that morning than before ..but not normal.

Changed fuel filter....ran like new.
Rough ride on interstate.....gone.... it was the engine that had made it feel that way.

Similarities?

pas

Changed fuel filter about 6 months ago with motorcraft. Did cylinder 2 misfire go away with filter change or did you have to change coil pack and plug?

Jbrew

Some have to learn by making countless mistakes on their own before finally listening. Yea, it's slow and can be very costly.

techrep

iTrader: (1)

don’t forget new boots and springs too...

mbb

Wasnt cyl 2, it was two different cylinders , plus random code
Totally went away

pas

I've reset computer twice by pulling battery cable drive truck until check engine light comes on. I have used 2 different scanners and get the same and only P0356 code for cylinder 6. I figured I should be focusing there. Are you guys telling me the codes on the 2 different scanners are off?