The Most Common OM602 2.5-2.9 TDi Engine Problems

A series of diesel engines under the OM602 marking has become famous throughout the world. These are the engines that car owners associate with the term “millionaires”.

They were assembled from 1985 to 2001 and installed on many of the group’s popular cars. A similar diesel power unit was found on the Mercedes T1N Sprinter W901.

Its reliability is due to its extremely simple design: a five-cylinder cast-iron cylinder block, which is covered by an aluminum 10-valve cylinder head. The gas distribution mechanism is driven by a two-row timing chain with hydraulic valve actuators.

Today, such a design cannot be found on modern motors, hence the difficulties with their maintenance and repair. This engine is easily amenable to repair and restoration measures.

If you follow this condition, then the mark of 450-500 thousand km will not become something transcendental. If you look at the design of the OM602, you can immediately see that the 2.9-liter Mercedes Sprinter engine had tremendous potential.

Partly for this reason, there are instances that have passed a huge number of kilometers. But in the process of operation, situations will inevitably arise that require solutions. The timing chain in this engine takes care of 200-250 thousand km, after which it stretches and requires a change.

It should be changed on time, because in the event of a break it leads to cracking of the cylinder head. Punches the gasket when using cheap coolant. Hydraulic expansion joints are already knocking at the turn of 100 thousand km from poor lubrication. In general, all diesel malfunctions are easily eliminated with minimal financial costs.

OM602 Specifications

Engine capacity2.5/2.9 liters
Maximum power, hp88-126
Maximum torque, N * m (kg * m) at rpm.231 (24) / 2400; 231 (24) / 2800
Fuel usedDiesel fuel
Fuel consumption, l/100 km7.9 – 8.4
engine’s typeInline diesel 5-cylinder
Gas distribution systemSOHC
Cylinder blockcast iron
cylinder headaluminum
Turbochargingdepends on modification
CO2 emissions, g/km199 – 204
Cylinder diameter, mm87
Number of valves per cylinder2 or 4
Maximum power, hp (kW) at rpm126 (93) / 4600
SuperchargerTurbine
Compression ratio22
Piston stroke, mm84

OM602 Modifications

Consider the known modifications of OM602.

  • 912 – a power unit with a displacement of 2497 cu. see. It develops a power of 94 hp. There are 2 valves per cylinder.
  • 911 – the same displacement, but higher power – 90 hp There are 4 valves per cylinder.
  • 962 – a version of the engine with a turbine, with the same volume, but already developing 126 hp. Valves per cylinder 2.

Detailed characteristics of the modifications are given in the table below.

602.9112497 cu. cm, power 90 hp (66 kW) Australia, USA, Japan
602.9112497 cu. cm, power 94 hp (69 kW)
602.9122497 cu. cm, power 94 hp (69 kW)
602.9302497 cu. cm, power 94 hp (69 kW)
602.9312497 cu. cm, power 84 hp (62 kW)
602.9382497 cu. cm, power 94 hp (69 kW) For Gelaendewagen, 24V electrical system.
602.9392497 cu. cm, power 94 hp (69 kW) For Gelaendewagen, 24V electrical system.
602.9402874 cu. cm, power 95 hp (70 kW)
602.9412874 cu. cm, power 88 hp (65 kW)
602.9422874 cu. cm, power 98 hp (72 kW)
602.9462874 cu. cm, power 95 hp (70 kW)
602.9472874 cu. cm, power 98 hp (72 kW) For Gelaendewagen, on-board network 24V.
602.9482874 cu. cm, power 97 hp (71 kW) For Gelaendewagen, on-board network 24V. OM 602 D29
602.9612497 cu. cm, power 122 hp (90 kW) turbocharged. OM 602 A. USA, Japan
602.9612497 cu. cm, power 126 hp (93 kW) turbocharged. OM 602 A
602.9622497 cu. cm, power 122 hp (90 kW) turbocharged. OM 602 A. USA, Japan
602.9622497 cu. cm, power 126 hp (93 kW) turbocharged. OM 602 A
602.9802874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602 DE LA
602.9812874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602A DE 29LA
602.9822874 cu. cm, power 129 hp (95 kW) turbocharged. OM 602 DE LA
602.9832874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602A DE LA
602.9842874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602A DE LA
602.9852874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602A DE LA
602.9862874 cu. cm, power 122 hp (90 kW) turbocharged. OM 602A DE LA
602.99063 KW (86 HP)
602.99472 KW (98 HP)

Service Regulations

The OM602 motor needs periodic maintenance.

  • Every 15 thousand km, change the oil and filter, as well as lubricate the working systems.
  • Once a year, renew the brake fluid, clean the drains.

Cars in which it was installed

The engine was installed on Mercedes C, EG class, as well as on Sprinter vans and onboard platforms. See the table below for details.

W201 C classBase sedan
S124 E-ClassStation wagon on W124 chassis
S210 E classStation wagon on W210 chassis
W124 E classBase sedan
W210 E classBase sedan
G460 G-ClassGelendewagen
G461 G-ClassGelendewagen
G463 G-ClassGelendewagen
SPRINTER 3-tvan (903)
SPRINTER 4-tflatbed/undercarriage (904)

TOP 5 breakdowns and problems of the OM602 engine

  • Strong vibrations of this diesel engine adversely affect the life of its supports;
  • The timing chain serves about 200 – 250 thousand km, and when it breaks, the block head cracks;
  • When using cheap or old antifreeze, it often breaks through the cylinder head gasket;
  • From low-quality oil, hydraulic lifters can knock on a run of 90,000 km;
  • Also, a lot of problems for the owners are thrown by the vacuum control system of the high-pressure fuel pump.

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