Cummins/Onan QST30 — Lubricating Oil and Filter Change
Maintenance · Lubricating oil system
For the Cummins/Onan QST30, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan G-Drive, Cummins/Onan QST30, Cummins/Onan QST30 engine
Before you start
- Avoid direct contact of hot oil with your skin. Used engine oil can be carcinogenic.
Parts for this job
Part numbers from the service-parts list for Cummins/Onan QST30. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Operate the engine until water temperature reaches 60 C [140 F]; shut off.
- Remove the oil drain plug from the bottom of the oil pan.
- Remove the oil filters with oil filter wrench Part No. 3375049.
- Clean the filter head and gasket surfaces.
- Coat new filter gaskets with clean 15W-40 oil; fill filters with clean oil.
- Install filters until the gasket contacts the head, then tighten 3/4 turn.
- Install and torque the oil drain plug to 60 N-m [45 ft-lb].
- Fill with clean oil and run engine at idle; check for leaks.
Tools required
- Oil filter wrench Part No. 3375049 Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Oil drain plug 60 N-m [45 ft-lb]
- Full flow 2.6 liters [0.7 U.S. gal]
- Bypass 2.3 liters [0.6 U.S. gal]
Full service-parts list: Cummins/Onan QST30 →
Source: Cummins/Onan 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.