Mercedes M264/M260 1.5/2.0L Engine Specs, Problems & Reliability
The Mercedes-Benz M260 and M264 replaced the previous M270/M274 engine series in 2017. The new series includes a 1.5-liter and 2.0-liter inline four-cylinder gasoline engines with turbocharger and direct fuel injection. Like the M270, the M260 was designed for models with transverse-mounted engines (front-wheel drive vehicles - ex. A-Class A220/A250/A35AMG). And the same as M274, the M264 refers to the longitudinal configuration and used in rear-wheel-drive models (such as C200/C300, E350, and CLS350). The M260/264 series is unified with the M256 3.0L inline 6-cyl engine.
The M264 and M260 are a further development of the previous M270/M274. They also have diecast aluminum engine blocks (crankcase) with cast iron cylinder liners. The manufacturer applied the CONICSHAPE technology in the production of the cylinder bores. It means that the cylinder bore is widened at the lower end of the cylinder liners and formed a conical shape, which minimizes piston friction and lowers fuel consumption. The new and old engine series share the same bore and stroke sizes except for the M264 1.5L engine - it has reduced by 2.6 mm cylinder bore size comparing to the previous 1.6-liter version. Like the predecessor, the M260/M264 2.0L version has a balance shaft located in the lower section of the crankcase. In addition to that, engineers introduced a new centrifugal damper into the powertrain and plastic engine mounts, making engine operation smoother and more comfortable. New engines got the pistons with cooling ducts and optimized piston rings.
On top of M260/264 engines, there is a freshly developed cylinder head made of aluminum-silicon alloy. It features four valves per cylinder, double overhead camshafts, and Mercedes CAMTRONIC mechanism for the intake side. The CAMTRONIC is a system that allows two-stage adjustment of the valve lift. In addition to the variable valve lift, there are two hydraulic camshaft adjusters providing variable valve timing for both intake and exhaust sides. The M260 and M264 use a toothed timing chain. The new 1.5L and 2.0L four-cylinders also have a direct multiple fuel injection system with latest-generation piezo injection valves but the position of the direct injectors has been optimized.
The M260 version is equipped with a single-pipe turbocharger, which features an electric wastegate actuator (the previous M270/274s had vacuum-operated actuators). The M264 engines come with a twin-scroll turbocharger and an electronically controlled wastegate valve as well. They also have improved intake manifold with short air paths in the interests of high power output and spontaneous engine response. The M264 1.5L and 2.0L engines are combined with a 48V electrical system. They are equipped with a belt-driven starter-alternator (BSA) and a 48V electric water pump by Magna. Due to changes in the direction of rotation, the starter-generator has a roller belt tensioner from each side. The belt itself is wide, seven-groove - and, according to engineers, it does not require replacement during the entire life of the engine. A petrol particulate filter is included for the M260 and M264 engines as standard.
Engine Specs
Mercedes M264/M260 Engine Problems and Reliability
New engines use proven and reliable ideas implemented and tested in the previous M270/M274 series. The manufacturer tried to lay as much durability as possible in its new base engines. As proof, they used cast iron sleeves/liners that can be repaired in the future, unlike Nanoslide coating. For a two-liter turbocharger M264, the thermostat opens at a relatively low temperature: 97 degrees Celsius (for most turbo BMW engines - 115 degrees Celsius). Together with an oil pan volume of 6.0 liters, it should positively affect on the durability of the oil and the engine itself.
But it is too early to talk about the long-term reliability of the M264 and M260 engines due to a short period of sales.