Service parts for the Marquis
Grouped by system, with how many of each the parts manual calls for.
Air intake
1 requiredFuel system
1 requiredOil system
1 requiredPrices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.
Specifications
Ratings spec sheet not in our library yet — see the documents below.
Maintenance & consumables
| Item | Spec | Capacity | Part # | Interval | |
|---|---|---|---|---|---|
| Air filter | Air Filter | 100-025-000 | Amazon eBay | ||
| Fuel filter | Fuel Filter | 100-045-000 | Amazon eBay | ||
| Oil filter | Oil Filter | 100-030-000 | Amazon eBay | ||
| Battery | — | ||||
| Belt | — | ||||
| Coolant | — | ||||
| Coolant filter | — | ||||
| Oil | — | ||||
| Spark plug | — |
Service intervals
6| Item | Action | Hours | Months | Notes |
|---|---|---|---|---|
| engine oil level | Check | 8 hr | Check the oil level daily or every 8 hours of operating time; do not check while the generator is running. | |
| engine oil and oil filter | Change | 150 hr | First service — Every 100 to 150 hours after the first 20-hour change (see Maintenance Chart). | |
| air filter | Change | 12 mo | Perform at least once a year (footnote 4); more often in dusty environments (footnote 2). | |
| battery and connections | Clean | 1 mo | Clean & check battery & connections monthly; perform more often when operating in hot weather (footnote 3). | |
| coolant system | Drain | 24 mo | Quiet Diesel: flush coolant system at least once every two years (footnote 8). | |
| generator exercise | Other | 1 mo | Run gasoline generators at a minimum of 50 percent capacity (2000 watts, or one air conditioner for a 4000-watt set) for two hours once every four weeks. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Recommended fluids
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|---|---|---|---|---|
| Coolant | 50/50 mixture of ethylene glycol based antifreeze and water | Use clean, soft water; mix thoroughly before adding; select high quality antifreeze with corrosion inhibitors. | |||
| Engine oil | 15W-40 (OnaMax) | API CF, CF-4, CG-4, CH-4, CI-4 or CJ-4 (diesel engines) | Synthetic oil not recommended during warranty period; synthetic oil does not extend maintenance intervals. | ||
| Engine oil | SAE-30 or 15W-40 (OnaMax) | API SJ, SL or SM (gasoline engines) | SAE-30 is the preferred summer grade for air-cooled engines; multi-grade oils (such as SAE 15W-40) recommended for year-round use in liquid-cooled engines. New generators are factory prepared with Onamax 15W-40. | ||
| Fuel | ASTM-No.2-D, ASTM-1-D, No.2-DLS, No.1-D, No.1-DLS, B5 Biodiesel; B20 requires additional fuel/water separator | ASTM certified, minimum Cetane number 45 | No.2-D/No.2-DLS for ambient greater than 23F; No.1-D/No.1-DLS for ambient less than 23F; B5 biodiesel for ambient greater than 50F. | ||
| Fuel | HD-5 grade liquid propane gas, mixture of at least 90% propane | HD-5 | Propane other than HD-5 can contain more than 2.5 percent butane. | ||
| Fuel | Regular unleaded gasoline; Ethanol blend not more than 10%; Methanol blend not more than 5% with solvents and corrosion inhibitors | Gas should not be more than 30 days old; use fresh gas. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Fault codes
4| Code | Name | Meaning | Severity | Action |
|---|---|---|---|---|
| 2 | Low oil pressure fault | Two blinks of the status indicator light at a time indicates a low oil pressure fault. | ||
| 3 | Service fault | Three blinks indicates a service fault. Press Stop once to cause the two-digit second-level fault code to blink. | Press Stop once to display the two-digit second-level fault code; press Stop again to stop blinking. | |
| 4 | Overcrank | Four blinks indicates that cranking exceeded 30 seconds without the engine starting. | ||
| 36 | Example second-level fault code | Fault Code No. 36 blinks as: blink-blink-blink (pause) blink-blink-blink-blink-bl (long pause) repeat. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
6Carburetor Pre-Heater Setting adjustment
- On carbureted models with a manual pre-heater control lever, set the carburetor air pre-heater for the temperature and humidity at your location.
- For temperatures below 55F and/or high humidity, set the selector in the winter position.
Reading Second-Level Fault Codes diagnostic
- Three blinks indicates a service fault.
- Press Stop once to cause the two-digit, second-level fault code to blink.
- The two-digit code consists of 1, 2, 3, 4 or 5 blinks, a brief pause, then 1 to 9 blinks.
- First set of blinks is the tens digit; second set is the units digit.
- Press Stop again to stop the blinking.
Restoring Fault Code Blinking diagnostic
- Note that blinking stops after five minutes (15 minutes, Series HGJAA).
- Press Stop three times within five seconds to restore blinking.
- The last fault logged will blink even after the condition has been corrected.
Checking Engine Oil Level maintenance
⚠ Hot oil can be thrown out of the dipstick hole, causing severe burns.
- Make sure the vehicle is level when checking oil level.
- Do NOT check the oil level while the generator is running.
- On models with a screw-type dipstick, screw the dipstick in completely for the correct reading, except RV QG 2800/2500 and RV QG 2800/2500 RM where it sits on top of the fill tube.
- Keep the oil level as near as possible to full; do not overfill.
Breaking In Your New Generator operation
- Run the generator at about 50 percent load for two hours.
- Run at about 75 percent load for two hours.
- Let it cool down.
- Change the engine crankcase oil after the first 20 hours of operation, and every 100 to 150 hours thereafter.
Starting And Stopping Procedures operation
- Turn off air conditioners and large electrical loads before starting.
- Before starting in cold weather, turn off all appliances.
- Prime by holding stop (all Quiet Diesels, Quiet Gas 3600-7000).
- Press and hold start at the control panel or at the set.
- Quiet Diesel: auto pre-heat flash, then crank/start.
- Do not over-crank with no start.
- Let the generator warm up a few minutes before turning on appliances.
- Turn off air conditioners and large loads and run 3-5 minutes before stopping.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Common questions
What oil filter does the Cummins/Onan Marquis use?
The Cummins/Onan Marquis uses oil filter part number 100-030-000.
What fuel filter fits the Cummins/Onan Marquis?
The Cummins/Onan Marquis uses fuel filter part number 100-045-000.
Which air filter part number does the Cummins/Onan Marquis take?
The Cummins/Onan Marquis uses air filter part number 100-025-000.
Troubleshooting
6Symptoms & remedies
| Symptom | Remedy |
|---|---|
| Dizziness | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Muscular Twitching | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Vomiting | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Weakness and Sleepiness | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| Inability to Think Coherently | IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the unit and do not operate until it has been inspected and repaired. |
| If the genset fails to start | See the Troubleshooting Guide in the Operator’s Manual |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing. Full Cummins/Onan Marquis troubleshooting guide (9 entries) →
Parts
4| Part # | Description | Qty | System | |
|---|---|---|---|---|
| 100-025-000 | Air Filter | 1 | Air filter | Amazon eBay |
| 100-030-000 | Oil Filter | 1 | Oil filter | Amazon eBay |
| 100-045-000 | Fuel Filter | 1 | Fuel filter | Amazon eBay |
| 965-0131 | Operator manual | Operator manual | Amazon eBay |
Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.
Available documents
Owner's manual — F-1123 Cummins-Onan RV Generator Handbook (07-2010) (Cummins/Onan)Service manual — 965-0631 Onan BGM NHM Marquis series RV Genset Installation manual (05-1992) (Cummins/Onan)
This page was generated from the 2 manufacturer documents above by automated extraction; every figure shown is copied from one of them. How the data is compiled.