Mercedes M272 Engine Problems: Causes And Solutions

The M272 is a six-cylinder gasoline engine developed by Mercedes-Benz, succeeding the M112. Initially, the engine was offered in the SLK of the R171 series, before it later found its way into numerous other Daimler models. In addition to the variant with manifold injection, a version with direct gasoline injection was also offered under the designation CGI (Charged Gasoline Injection, e.g., 350 CGI).

Mercedes M272 Engine Problems

Problems with the Balance Shaft

the-sprocket-of-the-balance-shatf-can-wear-prematurely-due-to-material-weakness

The sprocket of the balance shaft can wear prematurely due to material weakness, which usually results in engine damage. Engines with the numbers 272 9 [...] 30 468 993 are affected, or this problem can occur in all engines manufactured until the end of August 2006. A defective sprocket typically announces itself with an illuminated engine control light (Code 1200, 1208) - usually at a mileage between 37,000 to 87,000 miles.

Defective Intake Manifold

The plastic-made shift linkage of the intake manifold can break, usually leading to a noticeable loss of performance. Repair kits are offered to remedy the problem, but only the installation of a new intake manifold module can ensure long-term stability.

Faulty High-Pressure Pump

With CGI, the high-pressure pump may suffer a defect. If this fails, the repair can become quite expensive, as it is not easy to organize and is accordingly highly valued. A faulty high-pressure pump typically announces itself with a sewing machine-like clatter (clearly audible in this YouTube video).

Carbon in the Intake Tract and Valves

due-to-direct-gasoline-injection-m272-engine-have-to-contend-with-coked-injectors

Due to direct gasoline injection, the M272 CGI will have to contend with coked injectors and carbon deposits in the intake tract. To at least delay the resulting problems (loss of performance, increased consumption, etc.), it is advisable to use cleaning fuel additives that are added at regular intervals when refueling.

Further Weaknesses of the M272

NOx Sensor
Camshaft Adjuster Magnets
Camshaft Sensors
Deflection Pulleys
Serpentine Belt Tensioner
Engine Mounts

Mercedes M272 Technical Data

Baureihe	Hubraum	Leistung	Drehmoment
M 272 KE 25	2.496 cm³	150 kW (204 PS) / 6.100 UPM	245 Nm / 2.900 – 5.500 UPM
M 272 KE 30	2.996 cm³	170 kW (231 PS) / 6.000 UPM	300 Nm / 2.500 – 5.000 UPM
M 272 KE 35	3.498 cm³	190 kW (258 PS) / 6.000 UPM	340 Nm / 2.500 – 5.000 UPM
M 272 KE 35	3.498 cm³	200 kW (272 PS) / 6.000 UPM	350 Nm / 2.400 – 5.000 UPM
M 272 KE 35 CGI	3.498 cm³	215 kW (292 PS) / 6.400 UPM	365 Nm / 3.000 – 5.100 UPM
M 272 KE 35 Sportmotor	3.498 cm³	224 kW (305 PS) / 6.500 UPM	360 Nm / 4.900 UPM
M 272 KE 35 Sportmotor	3.498 cm³	232 kW (316 PS) / 6.500 UPM	360 Nm / 4.900 UPM

Conclusion

The M272 is a good engine for those who can cope with potentially high maintenance costs. You can read more about complaints related to the M272 engine here. To at least avoid the problem with the sprocket, it is advisable to opt for a Daimler that was manufactured after the end of 2006.