Feels like misfire but no codes | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Feels like misfire but no codes

apanello

Active Member
Joined
October 26, 2011
Messages
98
Reaction score
1
City, State
Illinois
Year, Model & Trim Level
2003 Explorer XLT 4.0
4.0, I seafoamed my ex a week ago. Ever since I have had issues. At idle rpms drop off and come right back sparatically. Under load and while driving, I feel like I am being rocked back and forth. Put it in N and it goes away. it feels like a misfire but I have no CEL on. What the heck did I do ? Very frustrated
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Ford PCM won't throw a code for misfire until it gets really bad. Start with checking vacuum leaks. I had a lot of trouble with rough idle and finally got it pretty well fixed but it took a while. See this thread.

I honestly don't think Seafoam or any similar product can do much good, and maybe cause problems like in your case. Where did you inject it? Maybe you fouled out some sensor or something...
 






released build up

SeaFoam removes carbon and other deposits that have accumulated in the engine. If the deposits are in the intake manifold (like from the EGR valve) they flow downstream (into the heads) when released. They can collect on the spark plugs and foul them. A similar thing can happen when adding certain fuel injector cleaners to the fuel tank. Some cause the deposits in the fuel tank, fuel lines and injectors to collect on the valves. That's why I normally use Techron fuel injector cleaner which was recommended by Volvo about 30 years ago. I used SeaFoam once to loosen the compression rings on my 850 Turbo Wagon engine after the previous owner had let it sit in a field for more than a year.
 






Update: it threw a code-cylinder 6 misfire.
 






I pulled Cyl 6 plug. It was black. I cleaned it up and put it back in. I put two cans of sea foam thru the brake booster. It ran great for a day, now it's back to the same crap.

So it must have something to do with Cyl 6. What do I do now? I'm stuck guys.
 












You mean coil pack? I was thinking about getting the screaming demon coil pack.

What do I test the cylender for?
 






compression

I would have tested the compression while the spark plug was out to see if it was low. Apparently you have coilpacks instead of a coil over each spark plug. Measure the resistance of cylinder 6 ignition wire and compare it to another cylinder wire resistance. Check the condition of each end connector. Read this thread: Engine misfire procedure
 






Nice thread, I'll test and post results
 






I replaced the plug in cly # 6. Idle feels rock solid at this time. We will see if it stays that way.
 






plugs

yesterday my engine 4.0 sohc engine was missing, there was no light on. I was surprised, I thought there was carbon on one of the plugs, so I tried to get the truck to a high rpm to burn off the carbon, the service engine light starting flashing, the truck went into safe mode, came to an idle and light shut off, changed plugs and wires all good now.
 






I just hope not to see any fuel or oil fouling in the future.
 






Back
Top