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Generac — Replace Engine Oil and Oil Filter

Maintenance · Engine Oil System

From a Generac owner's manual — check it applies to your exact model before use.

Applies to: Generac 15 kW EcoGen, Generac GT-999 engine

Before you start

  • Allowing engine at operating temperature ensures proper viscosity for draining.
  • Hot oil causes burns. Avoid prolonged skin contact.
  • Dispose of used oil at proper collection center.

Parts for this job

Part numbers from the service-parts list for Generac 15 kW EcoGen. Verify against your serial number before ordering; some links are affiliate links.

Procedure

  1. Ensure engine at operating temperature by running 20 minutes minimum.
  2. Press Control Panel OFF to shut down engine.
  3. Allow oil to settle 10 minutes.
  4. Remove used oil filter by turning counter-clockwise.
  5. Remove oil dipstick from tank.
  6. Set drill to clockwise direction and attach to drill pump drive shaft.
  7. Insert 1/4 inch hose into oil tank.
  8. Insert 1/2 inch hose into oil catch container.
  9. Spin pump on drill high speed setting.
  10. Ensure no kinks in hoses. May take 2 minutes to prime.
  11. Draw out as much oil as possible (2.5-3.5 quarts total).
  12. Remove 1/4 inch hose and drain pump.
  13. Apply light coating of new oil to filter gasket.
  14. Screw new filter on hand-tight until gasket contacts adapter.
  15. Tighten filter 3/4 to 1 full turn more by hand.

Tools required

  • Oil System Drain Pump Kit (Part No. 0K3717) Amazon
  • Drill (clockwise setting) Amazon
  • Oil catch container Amazon
  • Towel or small container Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

  • Oil change interval: 500 hours or 2 years
  • First service: after 25 hours
  • Cold weather (<40°F/4.4°C): every year or 100 hours
  • Hot weather (>85°F/29.4°C continuous): every year or 100 hours
  • Oil volume: 2.5-3.5 quarts (2.37-3.31 liters)

Full service-parts list: Generac 15 kW EcoGen →

Source: Generac owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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