MERCEDES E63 AMG CLS63 W219 M156 V8 156.983 engine complete

the M156.983 engine is a legendary naturally aspirated 6.2L V8 (often marketed as a 6.3L) that powered the W211 E63 AMG and the W219 CLS63 AMG.

As these cars approach “modern classic” status, finding a complete engine in good condition has become more difficult and expensive, especially units that have already been “bulletproofed” against the M156’s known architectural flaws.

1. Technical Identification

• Engine Code: M156.983.

• Displacement: 6,208 cc.

• Output: Approximately 507–514 hp and 630 Nm (465 lb-ft) of torque.

• Applications: * Mercedes-Benz E63 AMG (W211)

  • Mercedes-Benz CLS63 AMG (W219)

• Distinction: The .983 variant is specifically tuned and bracketed for the W211/W219 chassis. While it is physically similar to the .985 (C63), the oil pan, accessory drive, and ECU mapping differ.

2. 2026 Market Pricing (Estimated USD)

By 2026, pricing is split strictly between “As-Is” salvage units and “Refurbished/Bulletproofed” units.

3. The 2026 “Must-Check” List

If you are buying a complete M156.983, you must verify the status of these four critical areas. If they haven’t been addressed, you should budget an additional $4,000–$6,000 for parts and labor.

• Head Bolts: Early M156 engines used bolts that could snap, leading to coolant entering the combustion chamber. In 2026, any engine without the updated “tapered” head bolts (or ARP studs) is a liability.

• Camshafts & Lifters: The lifter buckets in the M156 often bleed down or wear through, eventually “eating” the camshaft lobes. Listen for a rhythmic ticking at idle.

• Cam Adjusters: The internal “plates” of the cam adjusters wear out, causing a loud rattle on cold starts.

• Intake Manifold: The magnesium center plate of the intake manifold can corrode or crack, causing vacuum leaks and lean codes ($P0171/P0174$).

4. Installation & Compatibility

• The “Plug and Play” Myth: While you can bolt an M156 from a C63 (.985) into a W211, you will need to swap the front sump oil pan and the oil pickup tube from your .983, as the C63 uses a different subframe clearance.

• ECU Pairing: If the complete engine comes with an ECU, remember that it is VIN-locked to the donor car. You will likely need to use your original ECU or have the donor ECU “virginized.”

• Oil Coolers: If your previous engine failed due to metal shavings (spun bearing), you must replace the oil cooler and all lines. You cannot effectively flush the debris out, and it will destroy the new engine.