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Generac 4.5L Engine Engine

Name: Generac 4.5L Engine
Brand: Generac

The Generac 4.5L is a 4.5 L 4-cylinder naturally aspirated engine rated at 1800 rpm, producing up to 69 kW. It powers generator sets from Generac, including the SG035, SG045 | 4.5L | 45 kW, SG050NA | 4.5L | 50 kW and SG070. It holds 20 L (5.3 gal) of oil and 50 L (13.2 gal) of coolant.

Also known as: Generac 4.5L

4.5 L

Displacement

Cylinders

1800 rpm

Rated speed

69 kW

Gross power

Engine specifications

Oil capacity	20.0 L
Coolant capacity	50.0 L
Displacement	4.5 L
Cylinders	4
Aspiration	Naturally Aspirated
Rated speed	1800 rpm
Gross power	69 kW

Generator sets powered by this engine

Generac SG035 Generac SG045 | 4.5L | 45 kW Generac SG050NA | 4.5L | 50 kW Generac SG070

Common problems

RPM Sensor Loss Shutdown H06
Fix: Check RPM sensor connections and replace if necessary.
Overspeed Shutdown H04
Fix: Reduce load immediately to prevent engine damage.
Overcrank Shutdown H05
Fix: Check fuel system and ignition components.
Low Fuel Pressure Warning H07
Fix: Check fuel system for leaks or blockages.
Low Engine Oil Pressure H03
Fix: Check and add oil if necessary, or replace oil filter.
Low Coolant Level H01
Fix: Add coolant to the proper level.
High Coolant Temperature H02
Fix: Reduce load or allow engine to cool.

Compiled from service & troubleshooting documentation across every generator set that uses the Generac 4.5L.

Maintenance schedule

Item	Capacity	Part #
Air filter		—	find
Fuel filter		—	find
Oil filter		—	find
Belt		—	find
Coolant	11.4 L	—
Oil	20.0 L	—

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Common questions

What is the oil capacity of the Generac 4.5L?

The Generac 4.5L engine has an oil capacity of 20.0 liters.

What is the displacement of the Generac 4.5L?

The Generac 4.5L has a displacement of 4.5 liters with 4 cylinders.

Which generators use the Generac 4.5L engine?

The Generac 4.5L powers 4 generator set(s), including Generac SG035, Generac SG045 | 4.5L | 45 kW, Generac SG050NA | 4.5L | 50 kW, Generac SG070.

What is a common problem with the Generac 4.5L engine?

A commonly reported issue on generators using the Generac 4.5L is: RPM Sensor Loss Shutdown. Fix: Check RPM sensor connections and replace if necessary..