Mercedes-AMG M156 Timing Chain and Camshaft Adjusters: Kit Guide

The naturally aspirated Mercedes-AMG M156 V8 is often described in vehicle badges and parts listings as 6.3, although its production displacement is approximately 6.2 litres. That naming difference is normal; it does not remove the need to confirm the engine and build. C63, E63, CLS63, ML63, S63 and CL63 searches can also span configurations and production changes.

When timing noise or camshaft faults appear, the parts decision can range from a chain-and-guide kit to a package with multiple camshaft adjusters. Those adjusters are costly and position-specific, while oil-control, sensors and base mechanical timing can imitate their symptoms. This guide helps turn M156 search terms into an evidence-based repair scope.

A V8 timing system requires bank-by-bank diagnosis

The M156 has two cylinder banks and multiple camshafts, so a single code description can hide important position data. Bank, intake/exhaust side and electrical/mechanical fault type should be recorded precisely. Replacing four adjusters because one bank responds slowly can add cost without addressing a sticking control solenoid, wiring problem or oil-supply issue.

Likewise, a basic chain kit must be evaluated as a system of chains, guides, tensioners and sprockets whose supplied contents vary by listing. The workshop should compare the kit with the engine’s original layout and the manufacturer procedure. Large-kit language such as ‘full set’ is useful for searching but is not a technical definition.

Symptoms that deserve a proper timing-system check

• Metallic rattle from the timing area during start-up
• Bank-specific camshaft position or correlation fault codes
• Rough running, reduced power or an engine warning
• One camshaft actual value failing to follow its target
• Noise or faults after previous camshaft/timing work
• Guide material, metal or abnormal contamination in the oil filter
• A symptom that becomes more pronounced as oil warms

Choose the repair scope from evidence

Package	Potential use	Critical check
Standard M156 timing kit	Verified chain/guide/tensioner repair	Exact supplied pieces and engine revision
Kit with VVT gears	Adjusters also fail inspection or control tests	Correct bank and intake/exhaust positions
Kit with RTV	Repair plan requires the specified sealant type	Service data—not the tube—sets application
Alternative VVT-inclusive listing	Contents or availability better match the job	No omitted or unnecessary components

The patterns above are diagnostic clues, not automatic replacement decisions. More than one fault can exist, especially on an engine with high kilometres, uncertain service history or previous internal work.

A step-by-step diagnostic sequence

1. Confirm M156 and build information

Use the VIN, engine number, production date and vehicle data. Do not order from the 63 badge alone because later and earlier AMG models can use different engine families. Record original part references and any known prior timing or camshaft repairs.

2. Map faults by bank and camshaft

Save codes and freeze-frame details, including bank and intake/exhaust wording. Graph requested and actual cam positions using the correct test. A bank-specific delay should lead to targeted oil-control, wiring, sensor and mechanical checks rather than automatic replacement of every adjuster.

3. Check the lubrication baseline

Confirm oil level, approved specification, filter condition and service history. Inspect the filter for debris and follow service information for oil-pressure testing where indicated. Hydraulic tensioners and camshaft-control mechanisms cannot be evaluated properly while supply pressure is unknown.

4. Localise noise and exclude external drives

Document cold and warm behaviour and use safe listening techniques to compare both cylinder heads, the front cover and accessory system. Avoid high-speed testing of a potentially mistimed engine. A repeating mechanical knock or misfire can indicate a wider issue requiring compression or borescope assessment.

5. Verify base timing and adjuster condition

Use M156-specific locking/holding tools and current procedures. Check timing references, guides, tensioner condition and sprockets. Evaluate adjuster play or locking behaviour only by the approved method; forcing a cam gear or using the chain as a holding device can create new damage.

6. Audit the proposed kit

Compare every chain, guide, tensioner, fixed sprocket, camshaft adjuster, seal and fastener with the workshop list. Confirm quantity and position for all VVT gears. If sealant is bundled, verify that its chemistry and application points match service information.

Four RunningRoo product options to compare

These are relevant catalogue links, not automatic fitment approval. Confirm the VIN, production date, engine code, original part numbers and exact kit contents with RunningRoo or a qualified workshop before ordering.

1. Mercedes-Benz M156 standard timing-chain kit — A base kit option for selected M156 applications after content and revision checks.

2. M156 timing kit with VVT gears — A gear-inclusive route when adjusters have been verified as part of the scope.

3. M156 timing kit with RunningRoo RTV — A sealant-inclusive listing; the exact application and all other consumables still require planning.

4. Alternative M156 VVT-gear timing package — Compare quantities, supplied adjusters and vehicle coverage with the repair schedule.

Precision work: four camshafts, two banks, one verification plan

Use the exact M156 procedure for engine position, camshaft holding, tensioning, torque angle and any single-use bolts. Marking the old chain with paint is not a substitute for locking and reference checks. Protect the open engine from contamination and account for any debris discovered in the oil circuit before installing clean components.

After specified hand rotation, recheck all bank and camshaft references. On start-up, monitor oil pressure and listen without unnecessary revving. Compare all commanded and actual camshaft positions, clear only documented codes and perform a controlled drive cycle. Reinspect the covers and sealing joints after full temperature, then rescan so an intermittent bank-specific fault is not mistaken for a completed repair.

• VIN, engine number and M156 production variant confirmed
• Codes mapped by bank and intake/exhaust camshaft
• Oil condition, pressure and debris assessed
• Base timing and each adjuster tested correctly
• Kit quantities, gear positions and consumables audited
• Mechanical references, live data and leaks checked afterward

More RunningRoo workshop videos

Continue with these related videos from the official RunningRoo Auto Parts YouTube channel:

• How to Check a VVT Sprocket | Camshaft & Timing Gear Inspection Guide
• Timing Chain Kit Explained – 4 Core Parts You Must Replace

Frequently asked questions

Is the M156 a 6.2 or 6.3-litre engine?

Its displacement is approximately 6.2 litres, while Mercedes-AMG marketed many vehicles with a 63 badge. Parts listings may use either description; verify M156 and the exact build.

Should all four M156 camshaft adjusters be replaced?

Not by default. Test and inspect each bank and position. Labour overlap and wear pattern may inform the plan, but each added adjuster must be correct and justified.

Can a camshaft solenoid cause an adjuster code?

Yes. Electrical control, oil flow, a sensor, base timing and the adjuster can affect the reported position. Diagnose the circuit and mechanics before ordering.

Does a timing kit include every gasket and bolt?

Do not assume so. Compare the listing against the service procedure and build a separate schedule for seals, one-time fasteners, fluids and any engine-specific consumables.

Final recommendation

M156 timing diagnosis should be bank-specific and component-specific. Confirm the engine, prove the oil and control baseline, verify base timing and inspect every adjuster before selecting a package. The correct kit is the one that matches the engine and evidence, whether it is standard or includes VVT gears.

This article provides general technical information. Confirm fitment and repair procedures against current manufacturer service data, and use a suitably qualified technician for internal engine-timing work.