2018 5.0 Cyl 2 4 Misfire & Random Mild Overheating

[Roweboat32]

Yes, I have read the other misfire posts but still have not resolved the problem.


Codes:

• P0300 (Random misfire)
• P05A1 (Active Grille Air Shutter A Position Sensor Min/Max Stop Performance)

Problems:

• Cyl 2 & 4 Misfires
  • Misfire counts after 10 min hard driving:
    • Cyl 1 = 5 - 10
    • Cyl 2 = 30 - 50
    • Cyl 3 = 5 - 10
    • Cyl 4 = 30 - 50
    • Cyl 5 = 5 - 10
    • Cyl 6 = 5 - 10
    • Cyl 7 = 5 - 10
    • Cyl 8 = 5 - 10
• Random Flashing CEL @ ~4000rpm & 20% load (varying ECTs)
• Random rich idle (11.5 - 13.0 throttle blip and goes away)
• Random rich/lean swings cruising @ constant throttle input (12.5 - 16.0)
• Random low power (engine sounds rough in high rpms + difference in butt dyno)
  • Drove to Denver from Minneapolis and the mountains greatly exaggerated this problem
• Random mild overheating (210 - 230F)
  • Drove to Denver from Minneapolis and the mountains greatly exaggerated this problem
• None of the above issues are dependent on each other

Diagnosis Steps:
New spark plugs (gapped 0.052)
New VCT solenoids (B1: Intake/Exhaust, B2: Intake)
Verified IMRC works properly
Replaced 2 problematic lower injectors
Bank swapped all lower injectors
Bank swapped all upper injectors
Bank swapped all coils except cyl3
Cleaned all upper injector o-rings & seats
Cleaned all lower injector o-rings & seats
Cleaned carbon from all intake runners
STP Engine Flush @ last oil change
Compression tested all cyls (w/ throttle closed, yes I know this isn't best practice)

• 1: 235 (low battery)
• 2: 235 (low battery)
• 3: 240 (low battery)
• 4: 230 (low battery)
• 5: 230 (low battery)
• 6: 240
• 7: 245
• 8: 250

Current Situation:
None of the diagnosis steps have made improvements except for carbon cleaning intake ports

Next Steps:

• Di-electric grease on porcelain of spark plugs
• Get motor hot, smoke test intake manifold
• Test wiring going to coil packs

If anyone has any recommendations or pointers I am all ears. Still haven't taken it to a dealer but if these next steps dont work I will.

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[Clint81]

I had a misfire on #4 that would only happen on track days. Flashing CEL, eventually the code would stick, the CEL would stay on and it would pull power. This would happen on every session, usually within the first couple of laps.

What eventually worked for me was executing a Misfire Monitor Neutral Profile Correction with HP Tuners VMC Scanner. Some would drag me across the coals, but I also set the Misfire detect sensitivity to 90% with HP VMC Editor. On my last weekend at Road Atlanta, I did not experience a single misfire-related CEL. I believe you can run the profile correction with ForScan as well, but I haven't tried it. I hope this helps with the misfires at least! Don't know what to say about the overtemps, 230 on the street seems way high.

 

[Call_Me_Bruce]

Have you checked fuel pressure?

For the overheat I'd get the shutter problem situated. That can't be helping.

 

[Roweboat32]

Have you checked fuel pressure?

For the overheat I'd get the shutter problem situated. That can't be helping.

No I haven't checked fuel pressure since its only on 2 cylinders, but I will cross it off the list.

The shutter problem: I have overheated with the shutters stuck wide open so I'm hesitant to say that's contributing, if I can get some more funds rolling in that is planned to get replaced. Unfortunate that you have to get the whole assembly instead of the motor.

 

[Roweboat32]

I had a misfire on #4 that would only happen on track days. Flashing CEL, eventually the code would stick, the CEL would stay on and it would pull power. This would happen on every session, usually within the first couple of laps.

What eventually worked for me was executing a Misfire Monitor Neutral Profile Correction with HP Tuners VMC Scanner. Some would drag me across the coals, but I also set the Misfire detect sensitivity to 90% with HP VMC Editor. On my last weekend at Road Atlanta, I did not experience a single misfire-related CEL. I believe you can run the profile correction with ForScan as well, but I haven't tried it. I hope this helps with the misfires at least! Don't know what to say about the overtemps, 230 on the street seems way high.

Thanks for the idea! I don't have an HP tuner but I will get ForScan downloaded and see if I can get that setup!

 

[Call_Me_Bruce]

If the shutters are stuck wide open and you experienced an overheat, I would then test the fan.

 

[ToddOman]

I had to perform the crank relearn after Roush SC installation & flash. Not aware it is an option in Forscan, but is in the Roush RDT per following:

PCM Flash with Roush RDT:



Following codes will likely exist after flash:
P160A: 2F-00 Control Module Vehicle Options Reconfiguration Error.
The PCM determines that clutch/transmission slippage is occurring & will go into a protection mode reducing throttle response.
P0315: AF-00 Crankshaft Position System Variation Not Learned.
Changes to the drive train or issues that exist can also generate this DTC which has the potential to result in a blown engine!

Resolve P0315: With Roush RDT after the KOEO (key on, engine on) of the EOL (end of line) procedure, choose the “Learn Misfire Profile” which requires at least one rev of the engine to ~4500 RPM.

Resolve P160A: With a tuner/diagnostic tool that can perform the PCM relearn function (i.e. Forscan).
Forscan: Click left "Configuration and Programming button" (computer chip). At the top, select "Module initialization/relearn vehicle data". Highlight that function and hit the play button, and follow the onscreen instructions. Rescan for DTC's and remove the P160A DTC if recurring by clicking on the yellow yield sign at the bottom. Drive and scan for DTC's again, but should be none. Also CEL should be gone.

 

[Roweboat32]

If the shutters are stuck wide open and you experienced an overheat, I would then test the fan.

@Call_Me_Bruce I finally got the car out of storage.
I removed the shutters and tested the fans. Fans run at 190. It now cruises at 185-195 instead of the usual 200-210. It does heat soak up to 215 at idle but I'm less worried about that.

I changed the air filter since it was dirty and put di-electric grease on the coil pack-to-spark plug connections on cyls 3&4.

Issues presented during 15mins of hard driving:
- Very rich idle (10-11:1)
- Very rich decel (13:1)
- no codes
Both of which were fixed by blipping the throttle.

Misfire counts after 15mins of hard driving:
1) 5
2) 106
3) 19
4) 170
5) 9
6) 9
7, 8) forgot to track these

Looked at live data after 15mins of hard driving:
Only thing that stuck out to me was...
LTFT = -7 to -8%

Conclusion: I am going to buy a data-logger to try and see what the injector duty cycles are on decel and at idle. The LTFT is telling me that it would be leaky injectors, but I've already bank swapped them so I'm convinced something else is going on.

Do you guys have a recommended data logger?

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