HomeEnginesCummins/Onan 4.0EGHW

Cummins/Onan 4.0EGHW Engine

The Cummins/Onan 4.0EGHW is a 4 L natural engine rated at 3600 rpm. It powers generator sets from Cummins/Onan. It holds 1.16 L (0.3 gal) of oil and 1.1 L (0.3 gal) of coolant.

Also known as: Onan 4.0EGHW

4.0 L
Displacement
3600 rpm
Rated speed
1.16 L
Oil capacity

Engine specifications

Oil capacity1.16 L
Coolant capacity1.1 L
Displacement4.0 L
AspirationNatural
Rated speed3600 rpm

Troubleshooting

7

Symptoms & remedies

SymptomCauseRemedy
FAILS TO CRANK (ELECTRIC START MODELS)Low Battery, Bad battery connection, Oil is too heavy, Load is connectedCheck battery electrolyte level and charge. Clean and tighten all battery and cable connections. Replace with lighter oil. Always disconnect load while starting.
CRANKS SLOWLY (ELECTRIC START MODELS)Choke closed, Dirty air filter, Rich fuel mixtureOpen choke. Clean or replace air filter. Contact an Onan service center.
ENGINE WONT STARTLoose or worn spark plug lead, Faulty spark plug, Dirty fuel filter or generator set at too steep of an angle, Governor out of adjustment or lean fuel mixCheck spark plug lead connection. Remove and clean or replace spark plug. Check fuel filter and generator set angle. Contact an Onan service center.
EXHAUSTING BLACK SMOKEOpen DC circuit breaker due to an overloadRemove all loads, reset circuit breaker, check for an overload or short circuit. Do not exceed generator set rated load specifications.
UNIT RUNS THEN STOPSAdd fuel. Add oil. Reduce oil level.
UNIT RUNS BUT SURGESAdd fuel. Add oil. Reduce oil level.
NO AC OUTPUT VOLTAGEOpen AC circuit breaker due to an overloadRemove all loads, re-set circuit breaker, check tools or appliances being used for defects. Do not exceed generator set rated load specifications.

Fault codes and symptom→remedy steps extracted from this engine’s service/owner documentation; verify against the official manual before servicing.

Common problems

7
  • UNIT RUNS THEN STOPS
    Fix: Add fuel. Add oil. Reduce oil level.
  • UNIT RUNS BUT SURGES
    Fix: Add fuel. Add oil. Reduce oil level.
  • NO AC OUTPUT VOLTAGE
    Cause: Open AC circuit breaker due to an overload
    Fix: Remove all loads, re-set circuit breaker, check tools or appliances being used for defects. Do not exceed generator set rated load specifications.
  • FAILS TO CRANK (ELECTRIC START MODELS)
    Cause: Low Battery, Bad battery connection, Oil is too heavy, Load is connected
    Fix: Check battery electrolyte level and charge. Clean and tighten all battery and cable connections. Replace with lighter oil. Always disconnect load while starting.
  • EXHAUSTING BLACK SMOKE
    Cause: Open DC circuit breaker due to an overload
    Fix: Remove all loads, reset circuit breaker, check for an overload or short circuit. Do not exceed generator set rated load specifications.
  • ENGINE WONT START
    Cause: Loose or worn spark plug lead, Faulty spark plug, Dirty fuel filter or generator set at too steep of an angle, Governor out of adjustment or lean fuel mix
    Fix: Check spark plug lead connection. Remove and clean or replace spark plug. Check fuel filter and generator set angle. Contact an Onan service center.
  • CRANKS SLOWLY (ELECTRIC START MODELS)
    Cause: Choke closed, Dirty air filter, Rich fuel mixture
    Fix: Open choke. Clean or replace air filter. Contact an Onan service center.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan 4.0EGHW.

Common questions

What is the oil capacity of the Cummins/Onan 4.0EGHW?

The Cummins/Onan 4.0EGHW engine has an oil capacity of 1.16 liters.

What is the displacement of the Cummins/Onan 4.0EGHW?

The Cummins/Onan 4.0EGHW has a displacement of 4.0 liters.

Which generators use the Cummins/Onan 4.0EGHW engine?

The Cummins/Onan 4.0EGHW powers 1 generator set(s), including Cummins/Onan 4.0EGHW.

What is a common problem with the Cummins/Onan 4.0EGHW engine?

A commonly reported issue on generators using the Cummins/Onan 4.0EGHW is: UNIT RUNS THEN STOPS. Fix: Add fuel. Add oil. Reduce oil level..