Isuzu 4JJ1TT4 Engine Engine
The Isuzu 4JJ1TT4 is a 3 L 4-cylinder turbo, liquid cooled engine rated at 2000 rpm. It powers generator sets from Generac, including the MFH500.
Also known as: Isuzu 4JJ1TT4
Engine specifications
| Displacement | 3.0 L |
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| Cylinders | 4 |
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| Aspiration | Turbo, Liquid Cooled |
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| Rated speed | 2000 rpm |
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Generator sets powered by this engine
1Common problems
15- Water or air in fuel system
Fix: Purge air or remove water. See Removing Water From Fuel. - Oil pressure does not rise
Cause: Incorrect engine oil viscosity.; Insufficient engine oil level.
Fix: Change with oil of correct viscosity. See Draining Fluids—Central Fluid Drain System and Refilling Engine Oil.; Replenish oil. See Refilling Engine Oil. - Incorrect fuel type
Fix: Electromagnetic type fuel pump problem. - Faulty injection pump
Fix: Contact a GMASD. - Exhaust smoke is white
Cause: Insufficient warm-up time.
Fix: Conduct warm-up operation. - Exhaust smoke is black
Cause: Excessive speed.
Fix: Verify engine rpm. Check AVR adjustment. - Engine will not crank (electric start)
Cause: Discharged battery.
Fix: Replace battery. See Battery Installation and Replacement. - Engine running is unstable
Cause: Fuel system problem. - Engine problem
Fix: Contact a GMASD. - Engine overheats
Cause: No coolant.; Front of radiator is clogged with dust.; Sub tank cap is not tightened.; Fouled coolant.
Fix: Add coolant. See Adding Coolant.; Clean with soft brush.; Tighten or replace sub tank cap.; Clean inside of radiator and change coolant. See Adding Coolant. - Engine has no power
Cause: Clogged air cleaner.; Clogged pre-fuel filter.; Clogged fuel filter.
Fix: Clean element.; See Removing Water From Fuel.; Remove water and change element. See Removing Water From Fuel. - Engine cranks but will not start
Cause: No fuel.
Fix: Verify there is no fuel leakage and replenish. - Engine control system problem
Fix: Contact a GMASD. - Clogged intercooler
Fix: Contact a GMASD. - Clogged air cleaner
Fix: Clean or change element.
Compiled from service & troubleshooting documentation across every generator set that uses the Isuzu 4JJ1TT4.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Replace engine air filter | | 58741160706 | 750 hr | PartsGeek $43.97 |
| Fuel filter | Replace fuel filter element* | | — | 1000 hr | find |
| Oil filter | Replace engine oil and oil filter element | | 002737 | 1000 hr | PartsGeek |
| Belt | Check and adjust tension at least once per year. Replace if damaged or worn. | | — | 8760 hr | find |
| Coolant | Replace every 2 years, or as needed based on condition | | — | 730 hr | |
| Coolant filter | Check coolant for abnormal color | | — | 250 hr | find |
| Oil | SAE 10W-30 or equivalent | 15.85 L | 209649 | 50 hr | PartsGeek |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Filters for this engine
- Air filter: Isuzu 58741160706 Donaldson P543614 Wix 46932
Cross-referenced via Donaldson + OEM/engine-maker interchange — options to verify against your serial number, not confirmed for every exact variant.
Also used in
7- Isuzu ELF300 — Truck
- Sany SY115 — Excavator
- Sany SY125 — Excavator
- Sany SY135 — Excavator
- Sany SY135C — Excavator
- Sany SY155 — Excavator
- Sany SY155H — Excavator
Other equipment known to use this engine, via filter-application cross-reference — useful for sourcing parts even when your exact machine isn't listed elsewhere on this page.
Common questions
What is the displacement of the Isuzu 4JJ1TT4?
The Isuzu 4JJ1TT4 has a displacement of 3.0 liters with 4 cylinders.
Which generators use the Isuzu 4JJ1TT4 engine?
The Isuzu 4JJ1TT4 powers 1 generator set(s), including Generac MFH500.
What air filter does the Isuzu 4JJ1TT4 use?
The Isuzu 4JJ1TT4 uses air filter part numbers Isuzu 58741160706, Donaldson P543614, Wix 46932.
How often should you change the oil in the Isuzu 4JJ1TT4?
The Isuzu 4JJ1TT4 oil change interval is every 50 hours.
What is a common problem with the Isuzu 4JJ1TT4 engine?
A commonly reported issue on generators using the Isuzu 4JJ1TT4 is: Water or air in fuel system. Fix: Purge air or remove water. See Removing Water From Fuel..