OM654 low coolant warning and misfires from an internal intercooler leak

Engine / equipment

OM654 2.0 diesel in the Sprinter (VS30)

Period mentioned

Intercoolers built before 02/02/2024

Symptoms

Yellow low coolant warning with no leak to be seen; sometimes the engine misfires or surges. Possible codes: P25567B (coolant level too low) and P30040B (temperature sensor after the intercooler).

Possible cause described

The liquid-cooled intercooler (charge air cooler) leaks coolant internally, which reaches the intake and the cylinders. Mercedes-Benz also names two other possible causes: another leak in the cooling system or a modification of the system the brand does not allow. It is described in its XENTRY technical note LI09.41-N-079165.

Check for the garage

Pressure test of the cooling system. If it loses pressure with no visible leak, the garage removes the throttle valve or the charge air temperature sensor to look for coolant inside the intercooler and does a compression test. If confirmed, the coolant is cleaned out of the intake and cylinders and the intercooler (one built after 02/02/2024), glow plugs, oil and filter are replaced.

Cost cited in the source

No verified estimate; ask the garage for a quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database