Mercedes-Benz M137 engine (1998-02)

The Mercedes-Benz M137 was a V8 petrol engine that was first introduced in the W220 S 600 as a replacement for the M120 engine. With 84.0 mm bores and an 87.0 mm stroke, the M137 E 58 engine had a capacity of 5786 cc. For the M137 E 63 AMG version of the engine, bore and stroke were increased to 84.5 and 93.0 mm, respectively, for a capacity of 6258 cc.

The M137 engine had a 60-degree ‘V’ cylinder configuration, a light alloy crankcase with Silitec (Al-Si alloy) cylinder liners, an aluminium alloy cylinder head, sequential fuel injection, two spark plugs per cylinder, a single overhead camshaft per cylinder bank, three valves per cylinder, aluminium roller rockers and a compression ratio of 10.0:1.

The M137 engine also had a cylinder deactivation function whereby, at low loads and engine speeds below 3000 rpm, the six cylinders on the left bank of the engine could shut down to minimise fuel consumption.

The M137 engine was replaced by the M275 unit in 2002.

Oil cooler O-ring leaks

For the M137 engine, the oil cooler O-rings were susceptible to failing and causing an oil leak. Since the oil cooler was positioned in the valley between the cylinders, it was necessary to remove the cylinder heads to access and replace the oil cooler.