Chrysler 300 LX

392 cubic inches, 4.09-inch bore, 485 hp — the biggest factory NA V8 of the 2020s. Forged steel crankshaft where the 5.7 uses cast iron — the real upgrade. Powder metal rods, cracked-cap design. Pistons are hypereutectic, not forged — ring lands too thin for boost, supercharger kits crack them. Same MDS lifter failure on automatics — engine replacement $15,000. Manual 392s skip MDS. VVT and active intake give 45 lb-ft more than the old 6.1 SRT. On 0W-40 at 5k intervals, the rotating assembly outlasts the car.

• !! MDS lifter failure — $15,000 engine replacement from 120,000 km

  Same MDS failure as the 5.7 but with higher stakes. Deactivated rollers destroy camshaft, metal contaminates oil. Engine replacement $4,800-15,000 — replacements can fail the same way. Class action: Petro v. FCA. Manual 392s have NO MDS.

  Symptoms: Progressive ticking to knocking, misfires, check engine light, metal in oil
  4,800–15,000 $
  Ad MDS lifter 6.4 Hemi 39253021726AE lifter 6.4LMDS delete kit 6.4 392
• !! Piston failure under forced induction (modified only)

  Stock cast pistons not designed for boost. Ring land too close to crown, ring gap too wide. Supercharger or turbo kits crack pistons. Forged internals required before adding boost. Only affects modified engines.

  Symptoms: Misfires under boost, loss of compression, knocking, catastrophic failure
  3,000–12,000 $
  Ad forged pistons 6.4 Hemi 392Mahle forged piston 392
• ! Exhaust manifold stud breakage from 210,000 km

  Cast-iron manifold on aluminum head — thermal expansion mismatch breaks studs. Grade 8 replacement studs (6509863AA) are the fix.

  Symptoms: Ticking on cold start from exhaust leak, disappears as metal expands
  400–1,600 $
  Ad 6509863AA manifold stud Hemi 6.4ProMAXX 6.4 Hemi bolt repair

+ 1 more engine weaknesses + vehicle weaknesses

5.7L Hemi V8, cast iron block, pushrod two-valve — 375 hp and that unmistakable idle burble. MDS deactivates cylinders 1, 4, 6, 7 under light throttle — deactivated lifters run dry on cam lobes, metal debris destroys the camshaft. Class action: Petro v. FCA. Manual cars skip MDS entirely — no deactivation hardware, no lifter lottery. That is THE buying tip. Software delete via DiabloSport/HP Tuners: $400-650, prevents activation but lifters stay, voids warranty, costs 2-4 MPG. On 0W-40 at 5,000 mile intervals, the bottom end is solid.

• !! MDS lifter failure — camshaft destruction from 160,000 km

  MDS deactivates 4 cylinders under light load. Deactivated lifter rollers run dry, metal debris destroys camshaft. Class action: Petro v. FCA (1:22-cv-00621). Engine replacement ~$5,000. Manual cars have NO MDS — this failure doesn't apply to stick-shift Challengers.

  Symptoms: Loud ticking progressing to knocking, misfires, check engine light, metal shavings in oil
  1,500–5,000 $
  Ad MDS lifter 5.7 Hemi5038785AD lifter yokeMDS delete kit 5.7 Hemi
• !! Water pump failure from 160,000 km

  Plastic impeller separates or bearing wears. Weep hole dripping coolant is the early warning. Bearing failure causes pulley wobble.

  Symptoms: Coolant puddle under front, squealing noise, overheating, pulley wobble
  400–1,200 $
  Ad 53022091AA water pump 5.7 Hemiwater pump 300C 5.7
• ! Hemi tick — harmless or catastrophic from 75,000 km

  Metallic ticking from valvetrain on cold start. Can be harmless exhaust manifold leak or dangerous MDS lifter damage. Tick that persists past warmup is a red flag for lifter failure.

  Symptoms: Ticking on cold start, may disappear after warmup (exhaust) or persist and worsen (lifter)
  0–500 $
  Ad 5038785AD lifter yoke 5.7 Hemi53021726AE lifter bridge Hemi MDS

+ 1 more engine weaknesses + vehicle weaknesses