Used 7.3 Godzilla (gas): what to check before you buy

1Before you go

Run the VIN and ask for the paperwork on the campaigns below: a done recall or program is a solved problem, an open one is a free repair the seller has not had done.

• Run the VIN

  It confirms the engine and lists the campaigns for that model year. Whether a recall is still open on this VIN: nhtsa.gov/recalls.

• Safety recalls on this engine
  • 20V-599 · 2020 · Power train
• Programs, extended coverages and emissions recalls
  • Ford 24B27 (and supplements S1-S3) · Program · 2020-2024 F-250 to F-550 Super Duty, 2021-2025 E-Series / Econoline, 6.8L and 7.3L gas

  Plus 2 service bulletins on the recalls page.

2Cold start and idle

Ask the seller not to start or warm the engine before you arrive. Most of these only show on a cold engine; then let it idle and listen.

• Exhaust manifold leaks (broken manifold bolts)
  • ticking at cold start that quiets as metal warms (classic leak signature)
• Fuel delivery service (in-tank pump / filter / PFI injectors)
  • long crank / low rail pressure complaints on high-mileage trucks
• Ignition service wear (plugs / coils)
  • gradual roughness, longer crank, misfire codes at service mileage
• Cracked oil pump drive gear (front-of-engine tick at idle, 2020-2022 7.3)
  • ticking / clicking / tapping at idle, loudest at the lower front where the timing cover meets the oil pan

3Scan for codes

A basic OBD-II reader shows stored and pending codes; on a diesel ask a shop for a full scan if you can. These are the codes our records tie to known failures on this engine.

What a code means on each engine: trouble codes by engine.

4Hood up and underneath

Engine off, in daylight, with a flashlight.

• Cam lobe and lifter (tappet) wear, worst with long idling
  • metal in the oil filter; owners report engine replacement once metal has circulated

  To confirm: locate the noise: lower front at the timing cover/oil pan seam on 2020-2022 = check the oil pump drive gear first (SSM 50830/51330); top end and following one cylinder = lifter/cam

• Cooling service (water pump / thermostat / degas)
  • weep-hole seepage / bearing noise on the water pump at higher mileage
  • temperature swings under tow; degas bottle level drift

  To confirm: pressure-test the system; inspect the weep hole and bearing play

5Test drive

At least 20 minutes, including a highway run and a hill or a load if you can.

• Cam lobe and lifter (tappet) wear, worst with long idling
  • tapping noise that progresses to a misfire on one cylinder and a rough run
  • check engine light / misfire codes (P0300-P0308), sometimes a flashing light under load
• Broken valve springs (sudden single-cylinder misfire)
  • sudden rough running / flashing misfire light on one cylinder, often at speed
  • compression miss that follows the cylinder, not the coil or injector
• Cracked oil pump drive gear (front-of-engine tick at idle, 2020-2022 7.3)
  • noise still present with the accessory belt removed

What it costs if you find it

Parts budgets from our repair recipes for this engine: Dave's Auto Center's prices where Dave's lists the part, approximate OEM and maker catalog prices (rounded) for the rest; labor not included. A campaign listed next to a failure may make the repair free on a covered truck: check it by VIN.