Vehicles using OM642.853 engine list:

Engine OM642.853

Symptoms:
- Rough idling and loss of power
- Excessive smoke from the exhaust, especially black or blue smoke
- Engine warning light (MIL) illumination
- Increased oil consumption or oil leaks
- Difficult starting or misfires
- Unusual noises such as knocking or rattling

Diagnosis:
- Check for fault codes using a diagnostic scanner to identify specific sensor or system failures.
- Inspect the turbocharger for wear or damage, as turbo issues are common.
- Examine the EGR (Exhaust Gas Recirculation) valve and cooler for clogging or malfunction.
- Test the glow plugs and fuel injectors for proper operation.
- Inspect the timing chain and tensioner for wear or elongation.
- Check for oil leaks around the valve cover gasket and oil cooler.
- Assess the DPF (Diesel Particulate Filter) status and regeneration cycles if equipped.

Fixes:
- Clean or replace the EGR valve and cooler to restore proper exhaust gas recirculation.
- Repair or replace faulty turbochargers to regain power and reduce smoke.
- Replace worn glow plugs and faulty fuel injectors to improve starting and combustion.
- Change the timing chain and tensioner if stretched or noisy to prevent engine damage.
- Replace valve cover gaskets and oil cooler seals to stop oil leaks.
- Perform DPF regeneration or replace the filter if clogged.
- Use manufacturer-approved engine oil and fuel to maintain engine health.

Prevention:
- Regularly service the engine according to Mercedes-Benz maintenance schedules.
- Use high-quality diesel fuel and engine oil meeting Mercedes specifications.
- Avoid frequent short trips that prevent the DPF from regenerating properly.
- Monitor engine warning lights promptly and address issues early.
- Periodically inspect and clean the EGR system to prevent clogging.
- Maintain proper oil levels and change oil at recommended intervals to protect engine components.