- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
Misfire code on 5.0 f150 (Update)
Posted on 8/15/19 at 12:05 pm
Posted on 8/15/19 at 12:05 pm
Code is P0306 Cylinder 6 misfire
Changed all spark plugs
Changed ignition coil.
New injector
Cleaned all injectors
Cleaned throttle body
Smoke test - no leaks
Compression test on cyl 6 showed 125psi
Code will show up for a week or so then go away for a week or so. Only problem I can pick up is it idles a little rough around 500-600 rpms but will smooth out around 700-800 with a little gas.
Any ideas?
Changed all spark plugs
Changed ignition coil.
New injector
Cleaned all injectors
Cleaned throttle body
Smoke test - no leaks
Compression test on cyl 6 showed 125psi
Code will show up for a week or so then go away for a week or so. Only problem I can pick up is it idles a little rough around 500-600 rpms but will smooth out around 700-800 with a little gas.
Any ideas?
This post was edited on 8/21/19 at 12:52 pm
8
Posted on 8/15/19 at 12:06 pm to jgthunt
Full disclosure I know nothing a out vehicles. I've been bringing it to a mechanic suggested by some good family friends.
Posted on 8/15/19 at 12:13 pm to jgthunt
quote:
Changed ignition coil
Motorcraft coil or cheap Chinese knockoff?
Posted on 8/15/19 at 12:16 pm to weadjust
Duralast, however we switched coil on cylinder 5 (oem) to 6 to see, and it still shows a 6 misfire.
Posted on 8/15/19 at 12:30 pm to jgthunt
So let's assume you have fire.
You appear to have compression. Did you take compression on any other cylinders?
So you could have a bad injector. Can you swap with another cylinder?
Or timing. I have seen a stretched timing belt do that, but normally on one whole bank.
You appear to have compression. Did you take compression on any other cylinders?
So you could have a bad injector. Can you swap with another cylinder?
Or timing. I have seen a stretched timing belt do that, but normally on one whole bank.
Posted on 8/15/19 at 12:35 pm to cajuncarguy
quote:
I have seen a stretched timing belt do that
quote:
5.0 f150
OP, Might have a crank sensor going bad causing random misfires
Posted on 8/15/19 at 12:39 pm to Bedhog
Ops, I meant timing chain 
Posted on 8/15/19 at 12:43 pm to jgthunt
Sounds a lot like a valve is not sealing off like a portion is burnt off. Compression builds with rpm and it goes to firing properly.
How many miles?
How many miles?
Posted on 8/15/19 at 12:44 pm to Barneyrb
100k
Posted on 8/15/19 at 12:47 pm to jgthunt
Checked the EGR valve?
Posted on 8/15/19 at 1:07 pm to TheDrunkenTigah
quote:don't think that motor had one
Checked the EGR valve?
Posted on 8/15/19 at 1:13 pm to jgthunt
was the spark plug on that cylinder really black?
or did it have any build up on it?
or did it have any build up on it?
Posted on 8/15/19 at 1:14 pm to Bedhog
I have no idea if it does or not, I just remember pulling one off my brother's f150 that was idling rough and misfiring. It was completely blocked with carbon. Cleaned it out and it eliminated the issue.
Posted on 8/15/19 at 1:22 pm to bbvdd
No, spark plug looked normal
Posted on 8/15/19 at 1:27 pm to TheDrunkenTigah
I'll check on the egr valve
And crank sensor
And crank sensor
This post was edited on 8/15/19 at 1:35 pm
Posted on 8/15/19 at 1:30 pm to TheDrunkenTigah
quote:a completely blocked off egr valve will cause no running issues. It's when they get stuck open is when you notice.
I have no idea if it does or not, I just remember pulling one off my brother's f150 that was idling rough and misfiring. It was completely blocked with carbon. Cleaned it out and it eliminated the issue.
Posted on 8/15/19 at 1:40 pm to Bedhog
I'll take your word for it, I just know the truck performed much better after cleaning it. Completely blocked was excessive wording, it just had a ton of carbon in it, buildup could have caused it to stick open.
Posted on 8/15/19 at 1:49 pm to TheDrunkenTigah
quote:that is usually the case. More times than not, if a vehicle is getting an insufficient egr flow code but there's no running problems, the ports in the intake manifold leading to the EGR valve are completely clogged up.
buildup could have caused it to stick open.
Posted on 8/15/19 at 2:06 pm to jgthunt
Mine will rough idle and die on occasion at a red light when the oil has about 25% life left. Looked it up online and seems it has something to do with vct solenoids if I remember correctly.
Posted on 8/21/19 at 12:54 pm to jgthunt
Brought it to Ford and they ran a diagnostic. Said I have low compression in cyl 6 and need a new head/gasket. Quoted me $4100 plus tax. This sound about right? Smaller shop do it cheaper? Should I just trade it in?
Page 1 of 2
Popular
Back to top
Follow TigerDroppings for LSU Football News