5.4L misfire rough idle
#1
Member
Thread Starter
5.4L misfire rough idle
OK i need some help. My truck just started this... After startup and driving for a bit my truck will suddenly idle rough and missfire (no codes). i push the gas and the idle smoothes out right away. Truck runs fine for a bit and happens again. It has done this a half dozen times now and seems to be getting more often.
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
The following users liked this post:
tamahue (07-04-2021)
#2
OK i need some help. My truck just started this... After startup and driving for a bit my truck will suddenly idle rough and missfire (no codes). i push the gas and the idle smoothes out right away. Truck runs fine for a bit and happens again. It has done this a half dozen times now and seems to be getting more often.
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
#3
Mark
iTrader: (1)
yep...thats where i would start...
#5
Mark
iTrader: (1)
Have fun...
#6
read up on the various issues with the 5.4l spark plugs.
There is plenty of information on this site. Some people have better luck than others.
I personally broke 7 off in the heads.
The lisle tool worked very well to get the remaining pieces out.
Just warning you.
There is plenty of information on this site. Some people have better luck than others.
I personally broke 7 off in the heads.
The lisle tool worked very well to get the remaining pieces out.
Just warning you.
#7
^ formerly hdub00
In my 5.4, I was noticing an issue about 3500-4000 rpm that the engine would shudder, if I was passing or just driving fast. I ignored it, until a week or so later, I was just driving around and the truck almost died, engine light came up, stayed on for about 20 seconds with terrible idle, then it cleared and seemed to run fine.
Took it to the ford dealership, 2 coils were burned out. I have some family friends up there and I got the 1500 tune up for 300. Runs like new now.
Took it to the ford dealership, 2 coils were burned out. I have some family friends up there and I got the 1500 tune up for 300. Runs like new now.
Trending Topics
#8
welding my life away
Join Date: Oct 2010
Location: Gwinnett, GA
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
OK i need some help. My truck just started this... After startup and driving for a bit my truck will suddenly idle rough and missfire (no codes). i push the gas and the idle smoothes out right away. Truck runs fine for a bit and happens again. It has done this a half dozen times now and seems to be getting more often.
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
Recent work
I have a K & N FIPK recently cleaned and oiled so we checked MAF and IA sensors and cleaned (very carefully)
Engine oil replaced with Lucus full synthetic cant see this causing any issue that would cause this?
Tomorrow will be using the scan tool to run diagnostics but i figured i would get a checklist going....
08 F150 SC 4x4 Lariat 5.4L Auto 110500Kms
Any ideas please
The following 2 users liked this post by Wizzard:
B-rad2 (12-22-2021),
MyBigRed89 (10-20-2022)
#10
I have a 2004, 5.4 3v and recently replaced plugs (E3’s) at 75,000 miles. After the plug change, CEL began blinking when accelerating, especially on the highway. Finally the CEL stayed on, truck ran rough and I had the code checked. Scan said multiple misfires and misfire on #6 and #8 cylinders. Replaced COP on #6 and #8, added fresh fuel with Lucas gas treatment. Now the engine only has a slight shutter on idle, not as bad as before. I want to pull the plugs on #6 and #8 and check them. Any other suggestions?