2018 Ford F150 5.0 Rough Idle and Timing Codes Diagnosis
Alright need some help diagnosing. 2018 F150 5.0 I start her up and she starts perfect. Idles for 15 minutes and then RPM’s drop below 500 and idle gets pretty rough. I then get the following codes: P0022 - Bank 2 timing over-retarded P0011 - Bank 1 timing over-advanced P0306 - Misfire Cylinder 6 I had a scanner hooked up and saw my oil pressure start out at 18-26psi then drop to 11-15psi at the same time the rough idle began. If I increase RPM’s to 1,500 or so, everything smoothes out and the misfires stop. If I place it in Neutral, RPM’s rise and problems stop. Stuff I’ve done: Replaced oil with 5W-30 Cleaned throttle body Replaced spark plugs Replaced camshaft position sensors Replaced VVT solenoids on Bank 2 My thought is the pump is bad. The oil gets hot, makes it thin, pump has an issue, can’t maintain pressure. or Theres another issue causing my RPM’s to drop which then causes my oil pressure to drop which then causes timing issues with the phasers which then causes misfires.
You’re on the right track. The most likely root cause is low oil pressure at hot idle — that’s what’s triggering the cam phaser (VCT) codes and the misfire. The 5.0 Coyote is sensitive to oil pressure for VCT operation. If the pump can’t keep up when hot, the phasers can’t hold position, timing goes out of whack, and you get misfires (especially on Bank 2, cylinder 6).
If oil pressure is truly dropping to 11-15 psi at hot idle (with correct oil and filter), the oil pump is suspect. But before condemning it, you need to rule out a false reading, a restriction, or a control issue.
If the idle is dropping because of a separate problem (like a vacuum leak or throttle control issue), that could also cause oil pressure to fall and cascade into VCT faults. But with your symptoms, oil pressure loss is the main suspect.
Most likely culprits
- Weak oil pump or internal leak — Can’t maintain pressure at hot idle, VCT phasers lose control.
- Sticking or failed VCT phasers — If phasers are leaking internally, they can bleed off oil pressure and cause timing codes.
- Incorrect oil filter or restriction — Cheap filters or debris can cause pressure drops, especially when hot.
How to narrow it down
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Verify oil pressure with a mechanical gauge
- Remove the oil pressure sensor, install a mechanical gauge, and check hot idle pressure. If it matches the scanner (11-15 psi), the issue is real. If it’s higher, suspect a sensor or wiring problem.
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Check for oil filter issues
- Make sure you’re running a quality filter (Motorcraft FL-500S or equivalent). Cheap filters can collapse or restrict flow, especially when hot.
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Inspect for oil leaks or consumption
- Check for external leaks, oil in the intake, or signs of burning oil. Low oil level can cause pressure drops.
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Scan for pending codes and monitor VCT data
- With the engine hot and idling rough, look at VCT actual vs. commanded angles. If they’re way off, phasers aren’t holding position — usually due to low oil pressure or failed phasers.
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Listen for timing chain/phaser noise
- Rattling or knocking at hot idle points to phaser or chain issues, often aggravated by low oil pressure.
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If pressure is low and all else checks out, suspect the oil pump
- Especially if the problem started suddenly or after an oil change with the correct parts.
Possible parts (if needed)
- Oil pump (if verified low pressure at hot idle)
- VCT phasers (if timing codes persist after oil pressure is fixed)
- Oil filter (if not Motorcraft or equivalent)
A few questions
- What brand/model oil filter are you running? (Some aftermarket filters are notorious for causing issues on these.)
- Did this problem start suddenly, or did it get worse over time?
- Any unusual noises at idle (rattle, knock, ticking) when hot?
Let me know what you find with the mechanical gauge — that’s the make-or-break step before tearing into the front cover.