Jeep Grand Cherokee
The cult V8 of the Mopar world — 360 hp with unmistakable Hemi sound. MDS (cylinder deactivation) is the problem: deactivated lifters receive no oil, needle bearings run dry on the cam lobe. Hemi Tick is NOT a normal sound but an early warning shot — MDS Delete with Hellcat lifters is the only permanent fix. Don't confuse exhaust manifold tick (harmless) with lifter tick (dangerous)! Sounds glorious, drinks heavily.
5.7 Hemi V8 — cult engine, MDS is the only real problem
360 hp Hemi V8: the best engine in the Grand Cherokee WK2. Sounds fantastic, runs 200k+ miles — if MDS is deleted and oil changed regularly. MDS Delete ($600) is mandatory for long-term owners. Fuel economy: ~13-16 mpg.
Engine Weaknesses 4
MDS cylinder deactivation shuts down 4 cylinders — deactivated lifters get no oil, needle bearings run dry on the cam lobe. Metal shavings in oil, camshaft destruction follows. MDS Delete with Hellcat lifters is the only permanent fix.
Symptoms: Loud ticking/knocking at operating temp, misfires, rough running, oil pressure drop
Water pump leaks or fails at higher mileage. Plastic impeller separates from the metal shaft, coolant escapes gradually.
Symptoms: Coolant loss, overheating, squealing from the engine bay
Metallic ticking from the valvetrain, especially on cold start. Can indicate dry-running lifter needle bearings — don't ignore. MDS tick (lifters) is far more dangerous than exhaust manifold tick (harmless).
Symptoms: Metallic ticking on cold start, disappears after warmup or gets louder
Exhaust manifold bolts snap from thermal expansion — the most common repair on the 5.7 Hemi. Manifold warps, bolts seize and break, especially rear passenger side.
Symptoms: Metallic ticking from engine bay, louder on cold start, exhaust smell inside cabin
Vehicle Weaknesses 5
Air suspension compressor fails — vehicle sags to one side or stays at wrong ride height. Expensive repair: compressor alone $500-1,200, more if air bag also failed.
545RFE/65RFE automatic transmission shifts harshly or erratically — valve body wears, torque converter slips. Especially on 3.6L versions from ~50k miles.
Alternator fails at higher mileage — typical for FCA vehicles of this generation. Battery no longer charges, electrics fail.
Electric liftgate actuator fails — tailgate no longer opens electrically. Typical wear on WK2 from ~50k miles.
Brake rotors warp from heat buildup — typical for heavy SUVs. Can occur as early as ~30k miles from aggressive or frequent braking.