Mercedes M272 & M273 Engine

The M272 V6 and M273 V8 sit in most Mercedes-Benz models built from the mid-2000s — C-Class, E-Class, S-Class, ML, GLK, SLK and CLS. They share one well-documented defect, and whether a given engine has it comes down to a single number stamped on the block. Not the model year. The engine serial number.

The gear failure, and why it differs by engine

Both engines wear out a gear in the timing drive, but not the same one:

• M272 (V6) — the balance shaft sprocket wears.
• M273 (V8) — the timing chain guide idler gear wears.

In both cases the gear teeth were made too soft and wear prematurely, sometimes without much warning. As the gear goes, timing drifts, and a failed timing chain on these engines means severe internal damage.

The numbers that decide it

Mercedes revised the components during production. Engines below these serial numbers are the potentially affected ones:

Broadly this covers model years 2004 to 2008, with the lawsuits focusing on 2005 to 2007. But the model year is only a rough guide. The serial number is the answer.

You will see this reflected in our own listings, which carry the engine ID cutoff where the supplier recorded it — for example “ML320 thru engine ID 40 186058, 4-21-06”. That is the level at which these engines have to be matched.

How to find your serial number

• Ask a Mercedes dealer with your VIN — they can read it off directly.
• Or read it from the block itself.
• Then compare against the cutoffs above.

Symptoms, and a code trap to avoid

Early signs are engine noise, a check engine light, misfires, rough running or stalling.

The only certain check is visual: remove the timing case cover and inspect the sprocket teeth on an M272, or the idler gear on an M273.

What happened with the lawsuits

There were two.

The first, Suddreth and Dunton v. Mercedes-Benz USA, alleged the gears failed prematurely and without warning. The court dismissed it, reasoning that because the gears typically failed between 60,000 and 80,000 miles, the failures fell outside the warranty period.

A second class action was filed in October 2012 in Northern California, covering 2005 to 2007 models. A preliminary settlement was reached on 8 April 2015, under which owners would be compensated for up to 70% of the repair cost.

If your car falls in that window and you paid for this repair, it is worth checking whether you were ever covered.

M272 variants and specifications

Variant	Displacement	Bore × stroke	Output
M272 E25	2,496 cc	88 × 68.4 mm	204 PS, 245 N·m
M272 E30	2,996 cc	88 × 82 mm	231 PS, 300 N·m
M272 E35	3,498 cc	92.9 × 86 mm	272 PS, 350 N·m
M272 E35 CGI (2006+)	3,498 cc	92.9 × 86 mm	292 PS, 365 N·m
M272 E35 (2008 uprate)	3,498 cc	92.9 × 86 mm	316 PS, 360 N·m

All are DOHC, four valves per cylinder, with continuously variable valve timing on both intake and exhaust camshafts, each adjustable over 40 degrees. Production ran 2004 to 2017 overall.

Note the CGI: the direct-injected CGI version is a different engine from the port-injected E35 despite the same displacement. Match the variant, not the litres.

Which models use which engine

Engine	Fitted to
M272 E25	C 230 · E 230 · CLC 230 · some Viano / Vito
M272 E30	SLK 280 · CLS 280 / 300 · CLK 280 · C 280 / 300 · E 280 / 300 · S 300 · GLK 300
M272 E35	Models badged 350
M273 (V8)	Models badged 450, 500 and 550

The quick rule: 280, 300 and 350 badges are M272; 450, 500 and 550 badges are M273.

Browse stock: used Mercedes engines · used Mercedes transmissions.

How we identify Mercedes engines

Mercedes uses a chassis type number rather than a simple VIN digit. You will see it in our listings written as, for example, “Engine 164 Type ML320” or “Engine 230 Type SL65” — 164 being the ML chassis, 230 the SL.

Three things decide fitment on these cars: the chassis type, the engine variant, and the engine serial number. Send your VIN to +1 (361) 470-5276 and we will confirm all three, including which side of the balance shaft cutoff your engine falls on. Free.

Which to buy

• Above the serial cutoff, always. An engine with the revised gears is a fundamentally different proposition from one without. This is the single most important filter on this platform.
• If the donor engine already had the gear replaced, that is just as good — ask for proof.
• Match the variant exactly. E25, E30, E35 and E35 CGI are not interchangeable, and neither are M272 and M273.
• Later production is the safer buy across the board, since Mercedes kept revising these engines through to 2017.

Used vs remanufactured

Used Mercedes engine prices

Our Mercedes engines start at $770, priced by variant, chassis and mileage. Mileage on every listing is read off the donor odometer rather than estimated, and we photograph the actual unit before it ships.

Live prices: used Mercedes engines.

What is included

Engines ship as tested assemblies. You transfer your own intake, sensors, accessories and flywheel or flexplate from the old engine. Each listing states what is attached to that unit, and the engine ID where the supplier recorded it.

Shipping and warranty

Every engine is compression tested and photographed on the pallet before dispatch, then crated for insured freight. Preparation takes 3 to 5 business days, then 2 to 4 days in transit. Shipping is free to any address in all 50 states, residential included.

Standard warranty is 6 months, extendable to 3 years, with 7-day returns and free return shipping. Full terms: engine warranty policy · shipping policy · returns.

Frequently asked questions

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