2016 F150 5.0 Code P0308
Thread Starter
|
6th Gear
Joined: Aug 2024
Posts: 6
Likes: 0
2016 F150 5.0 Code P0308
Hi Folks!
I am an old school gearhead with decent electrical and software skills from my days as an F-15 Avionics Tech and an industrial automation salesperson.
My son-in-law Joe is a 20 yr retired Navy Seebee with a used 2016 F150 4wd fancy model with the 5.0. - just over 100k on the odometer.
He and my daughter are raising my three beautiful pre-teen and teenage granddaughters - so money is tight and I work on their vehicles no charge - most times even buy the parts.
I will try to remember the events and timing, but it's been kind of a blur due to the extent of time that has passed and lack of documentation.
Joe has had misfire issues with this vehicle for what seems like the last 2 years. It either started with him changing the spark plugs or the spark plug swap was an effort to clear the code.
He used non-motorcraft. We changed them to the approved motorcraft plugs and the truck ran well for months.
Then a few months later - CEL Light came on - Using a basic OBDII reader - coded cylinder 3 misfire (P0303) - I changed the coil pack connector as it looked suspect (Joe is not gentle with things) - and that seemed to clear it up.
Then cylinder 5 misfire (P0305) to which I decided to change all the coil packs with new ones as Joe had piecemealed new ones in with old ones and we did not which was which.
That didn't resolve the code so I replaced the coil pack connector, and it ran well again for several months.
Now the truck is obviously running rough and throwing Cylinder 8 misfire (P0308). I swapped the plugs between 7 & 8 - code still there. Then swapped coil packs - code still there.
Replaced Fuel Injector - no change. Checked injector signal with Noid light and there is a pulse signal.
Then I compression checked all the driver's side cylinders (5 thru 8), and they were all at around 190-200 psi, including cyl #8.
I also learned about Forscan, and decided to download the software and purchase an adaptor (bbfly-BF32302).
Hooked it up, but that only confirmed the Code P0308 #8 Misfire.
Bought a new battery as the old one failed test. That changed nothing.
Removed the valve cover on the drivers side to look for any obvious mechanical issues with the valve train - especially on #8.
Everything in the valve train looked great - replaced both VCT solenoids while I had the cover off. No change.
I confirmed #8 is getting spark.
So if #8 is getting air, spark, and timing (at least mechanically) looks good, and the plug looks good - (seems dry when removed right after engine was running though)
I ran Forscan looking at the Manifold runners - see attached.
Looks suspicious to me but I don't know what the data should look like.
I could really use some help here...Any assistance is greatly appreciated!!
Thanks in advance!!
Tom Wright in Southern PA
I am an old school gearhead with decent electrical and software skills from my days as an F-15 Avionics Tech and an industrial automation salesperson.
My son-in-law Joe is a 20 yr retired Navy Seebee with a used 2016 F150 4wd fancy model with the 5.0. - just over 100k on the odometer.
He and my daughter are raising my three beautiful pre-teen and teenage granddaughters - so money is tight and I work on their vehicles no charge - most times even buy the parts.
I will try to remember the events and timing, but it's been kind of a blur due to the extent of time that has passed and lack of documentation.
Joe has had misfire issues with this vehicle for what seems like the last 2 years. It either started with him changing the spark plugs or the spark plug swap was an effort to clear the code.
He used non-motorcraft. We changed them to the approved motorcraft plugs and the truck ran well for months.
Then a few months later - CEL Light came on - Using a basic OBDII reader - coded cylinder 3 misfire (P0303) - I changed the coil pack connector as it looked suspect (Joe is not gentle with things) - and that seemed to clear it up.
Then cylinder 5 misfire (P0305) to which I decided to change all the coil packs with new ones as Joe had piecemealed new ones in with old ones and we did not which was which.
That didn't resolve the code so I replaced the coil pack connector, and it ran well again for several months.
Now the truck is obviously running rough and throwing Cylinder 8 misfire (P0308). I swapped the plugs between 7 & 8 - code still there. Then swapped coil packs - code still there.
Replaced Fuel Injector - no change. Checked injector signal with Noid light and there is a pulse signal.
Then I compression checked all the driver's side cylinders (5 thru 8), and they were all at around 190-200 psi, including cyl #8.
I also learned about Forscan, and decided to download the software and purchase an adaptor (bbfly-BF32302).
Hooked it up, but that only confirmed the Code P0308 #8 Misfire.
Bought a new battery as the old one failed test. That changed nothing.
Removed the valve cover on the drivers side to look for any obvious mechanical issues with the valve train - especially on #8.
Everything in the valve train looked great - replaced both VCT solenoids while I had the cover off. No change.
I confirmed #8 is getting spark.
So if #8 is getting air, spark, and timing (at least mechanically) looks good, and the plug looks good - (seems dry when removed right after engine was running though)
I ran Forscan looking at the Manifold runners - see attached.
Looks suspicious to me but I don't know what the data should look like.
I could really use some help here...Any assistance is greatly appreciated!!
Thanks in advance!!
Tom Wright in Southern PA
Last edited by tomthegtrplyr; Aug 24, 2024 at 02:14 PM.
Moderator
Joined: May 2005
Posts: 8,224
Likes: 1,236
From: San Antonio, TX
Welcome to FTE, tomthegtrplyr
Fords are real particular about spark plugs and coils. Nothing works very well for long except Motorcraft parts. That’s especially true for the coil packs.
Also, did all of the spark plug boots get replaced when the plugs were done?
Fords are real particular about spark plugs and coils. Nothing works very well for long except Motorcraft parts. That’s especially true for the coil packs.
Also, did all of the spark plug boots get replaced when the plugs were done?
Thread Starter
|
6th Gear
Joined: Aug 2024
Posts: 6
Likes: 0
Hi JKBrad,
Thanks for the reply.
That cylinder has spark - I took the coil pack and plug out of #8, had my son in law hold and ground the plug and it fired and even shocked him.
I already swapped the coil pack and plug between 7 and 8, and the misfire stayed with 8.
Installed a new injector in 8 - still coding misfire on 8 code P0308.
Can the fuel rail go bad on a 2016 F150 w/5.0?
I'm fairly confident it's not timing or spark so the only thing left is fuel.
Tom
Thanks for the reply.
That cylinder has spark - I took the coil pack and plug out of #8, had my son in law hold and ground the plug and it fired and even shocked him.
I already swapped the coil pack and plug between 7 and 8, and the misfire stayed with 8.
Installed a new injector in 8 - still coding misfire on 8 code P0308.
Can the fuel rail go bad on a 2016 F150 w/5.0?
I'm fairly confident it's not timing or spark so the only thing left is fuel.
Tom
Thread Starter
|
6th Gear
Joined: Aug 2024
Posts: 6
Likes: 0
In case you want to know how this troubleshooting process is going - go to the following link:
https://www.f150forum.com/f118/2016-...e-code-563144/
https://www.f150forum.com/f118/2016-...e-code-563144/
Thread
Thread Starter
Forum
Replies
Last Post
jarvisv77
Electrical Systems/Wiring
2
Sep 5, 2021 06:41 AM
tenneseetitanfan
2007 - 2014 Expedition & Navigator
3
Oct 5, 2020 02:02 PM
gdudik
1987 - 1996 F150 & Larger F-Series Trucks
15
Mar 25, 2020 07:31 PM
Resto Guy
Modular V8 (4.6L, 5.4L)
1
Nov 9, 2019 04:35 AM
