The Generac 5.4L is a 5.4 L 8-cylinder naturally aspirated engine rated at 1800 rpm. It powers generator sets from Generac, including the G35LG2, G40LG2, SG035 and SG040. It holds 5.7 L (1.5 gal) of oil and 11.36 L (3.0 gal) of coolant.
Also known as: Generac 5.4L
Part of the Generac 5.4L engine family — 2 variants share parts & fitment.
| Oil capacity | 5.7 L |
|---|---|
| Coolant capacity | 11.36 L |
| Displacement | 5.4 L |
| Cylinders | 8 |
| Aspiration | Naturally Aspirated |
| Rated speed | 1800 rpm |
Compiled from service & troubleshooting documentation across every generator set that uses the Generac 5.4L.
Step-by-step procedures compiled from the Generac service manual for this engine.
| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| Generator set | Inspect | 100 hr | 12 mo | First service — Level 4 mid-level inspection; annually or following each 100 hours of operation; approx. 5.0 man-hours; authorized Generac Service Dealer only; add 20% to all times for 8 cylinder or larger engines |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Type | Item | Value | Unit | Condition |
|---|---|---|---|---|
| Other | Frequency Regulation (Steady State) | ±0.25% | ||
| Pressure | Maximum Exhaust Backpressure | 1.5 | inHg | |
| Pressure | Maximum Radiator Backpressure | 0.5 | in H2O | |
| Speed | Rated Engine Speed | 1,800 | rpm | |
| Temperature | Max. Operating Ambient Temperature | 122 | °F | |
| Voltage | Regulation Accuracy (Steady State) | ±0.25% |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Coolant | 50/50 Ethylene Glycol Antifreeze | 11.36 L | Pressurized Closed Recovery cooling system type | ||
| Coolant | Half low silicate, ethylene glycol base antifreeze and half soft water (50-50) | 17.0 L | Cooling System SG035/045/075 = 17 L (4.5 U.S. gals.); do not use chromate base rust inhibitor or high silicate antifreeze boosters | ||
| Engine oil | SAE 10W or 15W-40 | For Service CC, SD, SE or SF | below 0°C | 4.25 L | Below 32 F (0 C) |
| Engine oil | SAE 20W-20 or 15W-40 | For Service CC, SD, SE or SF | -1°C to 27°C | 4.25 L | 30 to 80 F (-1 to 27 C) |
| Engine oil | SAE 30W or 15W-40 | For Service CC, SD, SE or SF | above 27°C | 4.25 L | Above 80 F (27 C) |
| Fuel | Natural Gas, Propane Vapor | Operating Fuel Pressure 8 - 14 in H2O (2.0 - 3.5 kPa); Secondary Fuel Regulator Standard |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
The Generac 5.4L engine has an oil capacity of 5.7 liters.
The Generac 5.4L has a displacement of 5.4 liters with 8 cylinders.
The Generac 5.4L powers 4 generator set(s), including Generac G35LG2, Generac G40LG2, Generac SG035, Generac SG040.
A commonly reported issue on generators using the Generac 5.4L is: RPM Sensor Loss Shutdown. Fix: Check RPM sensor connections and replace if necessary..