Vehicles using M113.940 engine list:

Engine M113.940

Symptoms:
- Rough idling or misfires
- Oil leaks around valve covers or intake manifold
- Reduced engine power or hesitation
- Check Engine Light (CEL) illumination
- Excessive oil consumption
- Engine overheating or coolant leaks

Diagnosis:
- Inspect ignition coils and spark plugs for wear or failure, as misfires are common in M113 engines.
- Check valve cover gaskets and intake manifold gaskets for oil leaks.
- Perform a compression test to rule out internal engine wear.
- Scan for diagnostic trouble codes (DTCs) to identify specific sensor or ignition issues.
- Inspect coolant hoses and thermostat for leaks or malfunction causing overheating.
- Examine PCV valve and related vacuum lines for clogging or damage.

Fixes:
- Replace faulty ignition coils and spark plugs to resolve misfires and rough running.
- Replace valve cover gaskets and intake manifold gaskets to stop oil leaks.
- Repair or replace leaking coolant hoses and thermostat to prevent overheating.
- Clean or replace the PCV valve to maintain proper crankcase ventilation.
- Address any DTCs by repairing or replacing affected sensors or components.
- Regular oil changes with recommended grade to reduce oil consumption and wear.

Prevention:
- Follow strict maintenance intervals for oil and filter changes using high-quality synthetic oil.
- Regularly inspect and replace ignition components before failure.
- Monitor coolant levels and condition to avoid overheating.
- Replace gaskets proactively if signs of leakage appear.
- Use OEM or high-quality replacement parts to ensure engine longevity.
- Keep the PCV system clean to prevent pressure buildup and gasket failure.

The M113.940 is a robust engine but benefits greatly from attentive maintenance to avoid common issues like ignition failures and gasket leaks.