Mercedes Benz OM611987 Engine (1998–2004) – Specs, Problems & Compatibility Database

Yes, the OM611.987 is known for mechanical durability and long service life when maintained properly. Early fuel pumps (pre-2001) are vulnerable to control rack wear in high-idle applications, but later revisions improved reliability. With regular oil and fuel filter changes, cooling system maintenance, and use of quality diesel, these engines routinely exceed 350,000 km. Its gear-driven timing and robust turbocharger contribute to excellent reliability in both personal and commercial roles.

The most common issues are fuel injection pump control rack wear (especially pre-2001 units), turbocharger bearing failure due to oil starvation, cylinder head cracking on the exhaust side, and oil leaks from the valve cover and rear main seal. These are documented in Daimler service literature and widely reported in technical workshops specializing in classic Mercedes-Benz diesel engines.

The OM611.987 was used in the W202 C-Class (C200 CDI, 1998–2000) and W904 Sprinter (208 CDI, 1998–2004). It was primarily offered in European and select export markets. Unlike some OM611 variants, it was not used in passenger sedans beyond the C-Class or licensed to other manufacturers.

Limited tuning potential exists. The mechanical fuel pump can be recalibrated to increase output by ~10%, raising power to approximately 88 kW (120 PS), but this increases stress on the pump and turbocharger. Turbocharging is already factory-fitted, but intercooler upgrades and exhaust modifications can support modest gains. Most owners prioritize reliability over performance, keeping the engine in stock form for maximum longevity.

Fuel economy is good by modern standards. In a W202 C200 CDI, expect ~7.8 L/100km (36 mpg UK) in mixed driving. The heavier W904 Sprinter 208 CDI averages ~9.0 L/100km (31 mpg UK). Economy improves with steady cruising but drops significantly under load. The engine's efficiency is limited by its indirect-injection design, though the turbo improves specific output over naturally aspirated variants.

No. The OM611.987 is a non-interference engine. If the timing gears fail or the camshaft stops, the pistons will not contact the valves. This design enhances durability and reduces catastrophic failure risk, making it well-suited for remote or commercial use where immediate repair may not be possible.

Mercedes-Benz specifies SAE 15W-40 oil meeting ACEA B3/B4 standards, compatible with MB 229.1. High-quality mineral or semi-synthetic oil is recommended due to the mechanical fuel pump's lubrication requirements. Oil should be changed every 15,000 km or annually, with fuel filter replacement at every second oil change to protect the injection system.