Chrysler 300 SRT8
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.
Last true SRT8 300
470 hp, Brembo brakes, adaptive suspension — the maximum in performance sedan from Chrysler. Rare to find, expensive to maintain.
Engine Weaknesses 4
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
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
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
Same tick as the 5.7 from MDS valvetrain. Tick persisting past warmup signals lifter damage. 0W-40 synthetic at 5,000 mile intervals is the best prevention.
Symptoms: Ticking on cold start, may persist or disappear after warmup
Vehicle Weaknesses 5
Totally Integrated Power Module controls all electrical functions. Relay failures cause: fuel pump runs continuously, horn sounds randomly, vehicle won't start. Repair service $200-350, new module up to $1,000.
Heater core leaks coolant into the cabin. Sweet smell, greasy film on inside of windshield. Very labor-intensive replacement — full dashboard removal required, 8-12 labor hours.
NHTSA recall for 133 model year 2023 Chrysler 300 vehicles with improperly adjusted parking brake from factory. Vehicle may roll away. Dealer adjusts parking brake free of charge.
Window regulator cable snaps, window drops into door or won't move. 91 reported cases on RepairPal. Affects all years and all doors.
Small plastic gears inside the blend door actuator strip out. Persistent clicking or ticking after startup or temperature change. Dashboard removal required for proper repair.
