Cummins/Onan Onan P4500i / P4500 — Changing the Engine Oil
Maintenance
For the Cummins/Onan Onan P4500i / P4500, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan Onan P4500i, Cummins/Onan P4500
Before you start
- Change the oil while the engine is warm but not hot
Procedure
- Turn the generator off and allow the engine to cool for 30 minutes.
- Depress the tab on the oil access cover and pull it away from the generator.
- Slowly unscrew and remove the oil dipstick.
- Remove the rubber plug under the oil drain bolt and place an oil pan under the drain hole.
- Using a 10mm wrench, remove the oil drain bolt and allow the oil to drain.
- Reinstall the oil drain bolt and rubber plug.
- Refill the oil as described in the Operations section.
- Replace the oil dipstick and hand-tighten; reinstall the cover.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Oil type: SAE 10W-30 Amazon eBay $54.99
Full service-parts list: Cummins/Onan Onan P4500i →, Cummins/Onan P4500 →
Source: Cummins/Onan operator'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.