I try to be pretty savvy with my vehicle but this series of incidents has me stumped. I've asked every technical person around me and they're coming up with nothing I'm not coming up with, thought I'd try here. I'll try to make it concise, but unsure if able.

Vehicle: 2016 F150 5.0L with 174,000mi

Initial problem: After 3 days of no driving (a week+ ago), started my truck on a cool morning only to have it make an awful noise from the engine (CLAK CLACK CLAK) spit whitish/grey smoke and stall itself in about a 3 second period. Freaked out, started it again under flooded start (in case phasers were to blame in a panicked mindset) and after this it started fine with no other issue I notice.

Findings: No codes thrown, started driving with Torque Pro on and monitoring everything, have looked at Forscan mode 6 data frequently. From this point forward, cold starts in the morning yield a bit of whitish smoke, kids complain of smelling gas at times.

I'm experiencing misfires across all bank 1 cylinders. Not enough to throw a code. Maybe 30-60 misfires per cylinder per 45 minute highway drive commute.

Misfires more common at elevated RPM (2500-3500) however they do occur in limited values at 1500-1800RPM cruising speeds.

LT fuel trim on bank 1 is always slightly negative between -3%- -6%. LT Fuel trim on bank 2 is always 0-4%. No issues on bank 2 whatsoever.

Monitoring O2 Sensor voltages shows some variance of bank 1 vs bank 2 with some dips on bank 1 that bank 2 never seems to match. During coasting/decel and a lot of crusiing the sensor behaviors match mostly.

Limited attempts to isolate; I've rotated some ignition coils from bank to bank no change. I cleaned up spark plug 3 (previous worst actor) and it reduced misfire some as it had some black buildup on it but it still misfires along with 1, 2, & 4.

What's next: I'm going to replace all spark plugs (they only have 40K miles on them, but whatever). I'm going to replace the fuel injectors. This one is a wild ass guess in that I think the LTFT on bank 1 is telling me I'm running rich, the smoke smells gassy on startup, maybe I have a leaker that's throwing the system array? My next path would be to look at the upstream O2 sensor on bank 1 but I don't want to go nuts on parts changes. (Being 175,000mi basically I feel like some parts changes are worthy, but within reason).

HELP: If anyone has any other ideas or data I can pull/look out I'll do it. Would appreciate any help on this as it has me lost.

Data from today while cruising at 72mph on flat hwy. Notice bank 1 voltage not matching bank 2

I think this was while I was lightly accelerating in the 50mph area

Order a borescope and inspect cylinders while you have the plugs out.

Interesting idea. Can you tell me what I'd look for (before I google it)?

You might have a cracked head gasket or crack in one or more cylinders allowing oil and/or coolant to accumulate in the cylinders. So you looking for rust, discoloration, a ridge in the cylinder at TDC or any other anomaly between cylinders.. Get one that connects to your phone and pics on here.

Have you disconnected your car battery for an hour or so... to see if forwhateverrason your vehice suffered an electonic anamoly... you know... to reset everything>

Just a wild-ass guess as that would be the first thing I'd do.

Pulling plugs... moving coils... boroscope sounds like a lot of BS when, you know... KISS.

lol gonna go do that right now.

Though I think the smoke on cold starts disqualifies a "brain" hiccup but we'll see.

McInnis 03 said:

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lol gonna go do that right now.

Though I think the smoke on cold starts disqualifies a "brain" hiccup but we'll see.

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Your smoke... likely the air/fuel ratio messed up caused by an electronic bug.

Yesterday replaced the battery in my 986. Went to start and it coughed... sputtered... and jerked when in gear backing up. Worse positioning it back into the driveway. Left it for the evening returning this morning. Same.

Put it in gear... gave it some gas... a little smoke... a little jerking... then everything settled in. Sometimes just an anomaly.

Keep us posted.

maybe try running some injector cleaner first? or bg44k

driver trims look ok to me. you typically add the ST and LT trims and if it's +/- 1-3% it's fine. passenger side looks slightly rich though.

sts7049 said:

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maybe try running some injector cleaner first? or bg44k

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Ran a 1/2 tank with a bottle of Redline SL-1 already. No changes.

txyaloo said:

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driver trims look ok to me. you typically add the ST and LT trims and if it's +/- 1-3% it's fine. passenger side looks slightly rich though.

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Yup, this is bank 1 and this is where the problems are.

I'm wondering out loud if a stuck open injector could cause faulty behavior across all 4 cylinders though.

Bank 1 and bank 2 o2 voltages continue to show differences even at steady state......I feel like I should be able to figure this out

Don't know that engine well but in a single bank on a dohc, the common parts are the fuel rail, the head gasket, the cam shaft and gear, maybe some intake parts.

I'd hope it isn't a jumped cam gear on a chain, or a cam shaft issue.

If it were the latter, would it possibly present itself far more frequently? This seems to be a minor issue if I'm being honest? At least at this point it is

Clack clack clack and white/gray smoke after sitting for 3-days in cool weather is what moves the needle here imo.

Garage camera caught it

https://streamable.com/t88ox0

Clacking sounds to me like chain tensioner. After sitting for a few days could have been a timing chain tensioner/guide bouncing before oil pressure got to it. Pressure is bleeding off due to worn out tensioner due to the mileage?

Could have resulted in a timing jump that is causing the random misfires across the bank now as others noted.

Any parameters for commanded vs. actual timing via scan tool?

The stall after the noise definitely concerns me, but it's running generally fine now minus the misfires. You are doing all the right things otherwise it seems. If you still have the issue after swapping plugs and injectors, timing would be the next thing to look into. Unfortunately I don't think that is possible to check/redo without pulling front cover.

I think I can get that data on forscan not not on Torque Pro. I'll check tomorrow

JamesPShelley said:

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McInnis 03 said:

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lol gonna go do that right now.

Though I think the smoke on cold starts disqualifies a "brain" hiccup but we'll see.

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Your smoke... likely the air/fuel ratio messed up caused by an electronic bug.

Yesterday replaced the battery in my 986. Went to start and it coughed... sputtered... and jerked when in gear backing up. Worse positioning it back into the driveway. Left it for the evening returning this morning. Same.

Put it in gear... gave it some gas... a little smoke... a little jerking... then everything settled in. Sometimes just an anomaly.

Keep us posted.

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Ugh. 986 is as analog as it gets. Never had that on my 986 from a battery disconnect. Maybe reset your secondary air intake system.

I know what's wrong with it. It ain't got no gas in it mmmmm hmmm./Carl

Side-pocket16 said:

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Clacking sounds to me like chain tensioner. After sitting for a few days could have been a timing chain tensioner/guide bouncing before oil pressure got to it. Pressure is bleeding off due to worn out tensioner due to the mileage?

Could have resulted in a timing jump that is causing the random misfires across the bank now as others noted.

Any parameters for commanded vs. actual timing via scan tool?

The stall after the noise definitely concerns me, but it's running generally fine now minus the misfires. You are doing all the right things otherwise it seems. If you still have the issue after swapping plugs and injectors, timing would be the next thing to look into. Unfortunately I don't think that is possible to check/redo without pulling front cover.

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So top 4 lines are bank 1 and bank 2 desired intake or desired exhaust minus actual intake or exhaust. They seem to be in line with one another..... but I'm no mechanic.

austinag1997 said:

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JamesPShelley said:

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McInnis 03 said:

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lol gonna go do that right now.

Though I think the smoke on cold starts disqualifies a "brain" hiccup but we'll see.

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Your smoke... likely the air/fuel ratio messed up caused by an electronic bug.

Yesterday replaced the battery in my 986. Went to start and it coughed... sputtered... and jerked when in gear backing up. Worse positioning it back into the driveway. Left it for the evening returning this morning. Same.

Put it in gear... gave it some gas... a little smoke... a little jerking... then everything settled in. Sometimes just an anomaly.

Keep us posted.

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Ugh. 986 is as analog as it gets. Never had that on my 986 from a battery disconnect. Maybe reset your secondary air intake system.

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Agreed. ABS and that's it... unlike my wife's G80. It's an attractive nanny, that's all.

Yeah... pulled the failed 8-year Bosch H6... plugged in the WM AGM H7... fired up... stumbled. Never had that happeeen... so I figured a remap.

The secondary system... fine. Coincidentlly... and if you know anything about that appliance throwing a code, not passing emmisions... I purchased after I bought the car a small device, off a seasoned forum member, that is installed in line/some wires/I'm not an electrician... and 100% guaranteed the car will pass SMOG. I digress. Tell me about your P-Car.

Changed plugs and injectors. Runs smoother. Won't know about smoke on startup for a bit but here's what the bore scope yielded.

I feel like I see some oil coming from the heads? Unsure.

Filllllthy cylinders.

Is there this much oil in every cylinder? If so, it almost seems like a cam timing issue may be causing this blow-by. Is this a VVT engine? It so, I'd replace those phasor injectors. If this is not the problem, then maybe pressure is getting build up in the crankcase somehow (failed PCV system?).

Bonfire97 said:

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Is there this much oil in every cylinder? If so, it almost seems like a cam timing issue may be causing this blow-by. Is this a VVT engine? It so, I'd replace those phasor injectors. If this is not the problem, then maybe pressure is getting build up in the crankcase somehow (failed PCV system?).

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Every cylinder on both sides had it. Only one side "acting up" though.

What did the old plugs look like? Anything to be gleaned from that?

They had a black layer on all of them. Both sides.

Misfires have decreased some on bank 1 with the cleanup. I'll have a better idea after the morning commute tomorrow.

Finally. Just got a pending p2610

McInnis 03 said:

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Finally. Just got a pending p2610

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So interestingly enough the pending code went away after I drove to the gym, turned the vehicle off and turned it back on. I wonder if remote starting is part of the problem? The P2610 code supposedly means the engine didn't know how long it was off since last start........could remote start be toying with it?

Anyways, drove to work just fine after the gym and I drove higher RPMs to try and burn off some of the gunk in the cylinders, left it in 4th gear and drove about 20 miles at 3000RPM on cruise control.

The O2 sensors and fuel trims on both banks were remarkably equal. Just to be sure, I pulled DTC codes on Forscan when I got to the office and noticed a P316 (startup misfires) which I believe was timed to be the startup when the P2610 pending was thrown.

Also interesting to me is that when this P2610 pending code was brought into the system, I got a TON of "U" codes from other modules. The "U" codes are all "Lost communication with" and tie to all the modules like the BCM, HVAC, ICM, Power Steering, APIM, etc. If I were a smarter man I might think this is some electrical snafu somewhere...........

Anyways, here's the meat and potatoes of when the code supposedly encountered:

Module: Powertrain Control Module

Freeze Frame #1:

Freeze Frame #2:
-TOTAL_DISTANCE: 173626 miles - Total Distance
-FUELSYS: Closed Loop - Fuel System Status (Open/Closed Loop)
-LOAD: 27.84 % - Calculated Load Value
-ECT: 75 F - Engine coolant temperature
-SHRTFT1: -7.03 % - Short term fuel trim 1
-LONGFT1: 1.56 % - Long term fuel trim 1
-SHRTFT2: -7.81 % - Short term fuel trim 2
-LONGFT2: 3.91 % - Long term fuel trim 2
-MAP: 4.6 psi - Manifold absolute pressure sensor
-RPM: 1267 1/min - Engine Revolutions Per Minute
-VSS: 0.0 mph - Vehicle Speed
-SPARKADV: 15.00 - Spark Advance
-IAT: 59 F - Intake Air Temperature
-RUNTM: 37 s - Time Since Engine Start
-EVAP_PCT: 0.00 % - Commanded Evaporative Purge
-FLI: 51.37 % - Fuel Level
-BARO: 14.5 psi - Barometric pressure
-VPWR: 14.83 V - Control Module Voltage
-TP_REL: 7.06 % - Relative Throttle Position
-TAC_PCT: 8.63 % - Commanded Throttle Actuator Control
-RPMDSD: 1250 1/min - Desired Idle Speed RPM
-O2S12: 1.58 V - Heated Exhaust Gas Oxygen Sensor (bank 1, sensor 2)
-O2S22: 1.65 V - Heated Exhaust Gas Oxygen Sensor (bank 2, sensor 2)
-TQ_CNTRL: Idle Speed Control - Torque Control Requested
-ENGOFF_TIMER: 58293 s - Timer since Engine Off
-APP_FLT: No Fault - Accelerator Pedal Position Sensor Status
-CHT_F: No Fault - Cylinder Head Temperature Sensor Status
-CHTIL: Off - Cylinder Head Temperature Indicator Lamp
-IAT_F: No Fault - Inlet Air Temperature Sensor Status
-ETC_TRIM_LRN: Yes - Throttle Angle Offset has Learned
-MISFIRE: No - Engine Misfire currently detected
-TP_F: No Fault - Throttle Position Sensor Status
-FF_LRND: Yes - Inferred Flex Fuel Learned
-IMRC: Off - Intake Manifold Runner Control
-IMRC_F: No Fault - Intake Manifold Runner Control Fault
-MP_LRN: Yes - Misfire Profile Correction Learned
-MAF_F: No Fault - Mass Air Flow Sensor Status
-MAP_F: No Fault - Manifold Absolute Pressure Sensor Status
-OTS_STAT: Enabled - One-Touch Start Status
-SMC_MON: Off - Starter Motor Control Output Detected
-STRT_RLY: Disabled - Starter Motor Relay Enable
-APP1: 0.75 V - Accelerator pedal position sensor 1
-APP2: 0.38 V - Accelerator pedal position sensor 2
-TP1: 4.22 V - Throttle Position Sensor 1
-TP2: 0.77 V - Throttle Position Sensor 2
-GEAR: 1 - Gear Commanded
-GEAR_OSC: 1 - Gear Command by Output State Control
-TSS_SRC: 1248 1/min - Actual Turbine Shaft Speed
-OSS_SRC: 0 1/min - Actual Output Shaft Speed
-TFT: 60 F - Transmission Fluid Temperature
-TR: Park - Transmission range

What kind of gas are you running? If you have e85 nearby, I'd switch over to it for a while.

ETA: Presuming Galveston County is correct, here's a map of e85 for you. I get mine from the Sunoco at 96 & 45.