Monaco Coach Diplomat Problems by Model Year
NHTSA recorded 30 consumer complaints across the 3 model years of the Monaco Coach Diplomat (1999–2001) that have at least 5 complaints. 2000 has the most, with 14. Across all years, the part named most often is body and structure (8 mentions). Pick a model year below to see its parts, mileage, recalls and service bulletins.
All Diplomat model years
Years with fewer than 5 complaints are not listed. The score compares years of the same model, allowing for the era and for how long each year has collected complaints: 50 is a typical year, lower means fewer complaints. It is not adjusted for sales volume.
| Year | Complaints | Median mi | Recalls | TSBs | Score (50 = typical) | Trend |
|---|---|---|---|---|---|---|
| 2001 | 6 | 29,000 | 4 | 0 | — | Not enough data |
| 2000 | 14 | 24,184 | 2 | 0 | — | Not enough data |
| 1999 | 10 | 38,218 | 3 | 0 | — | Not enough data |
Parts named most often, all years
Counts add up complaint mentions across the listed years. A complaint can name several parts.
- Body and structure8 22%
- Visibility (wipers, defrost, mirrors)7 19%
- Equipment7 19%
- Tires4 11%
- Suspension3 8.1%
- Fuel system3 8.1%
- Electrical system3 8.1%
- Other or unknown2 5.4%
Example complaints
One per model year, chosen for length and detail. Personal details are removed. They are consumer reports, not findings.
2000: “On 10/15/02 while driving my rv to a campground, I detected a very strong odor of antifreeze inside the rv and noticed wetness on the carpet near the fire wall. It rendered the defrosting of the front windshield nil and couldn't hardly see outside and damage the side compartment of the r.v. The unit was under warranty and monaco replaced the damaged heater core on 12/23/02. On 1/20/08 on a trip to orlando the same problem occurred again. I almost passed out at the wheel because of the strong odor of antifreeze leaking again inside the coach. Same problem: spited heater core. …”
NHTSA complaint #10217135, filed 2008-02, 16,000 miles2001: “: the contact stated the left driver's side window had poor visibility due to a separation of the double panel glass. He contacted the manufacturer, and they offered no assistance. This is a 2001, monaco, Diplomat rv. Updated 12/27/2005 - the consumer explained that the glass was cloudy, with moisture between the panes, which made it difficult to see out of the window, especially at night.”
NHTSA complaint #10143949, filed 2005-11, 29,000 miles1999: “Recall received for the wrong PSI on the original tag for tire equipment/ vehicle suffered tire blowout. The consumer received recall 03v386000 which indicated that the wrong PSI was put on the original id tag. The consumer contacted the local dealer but they refused to handle the recall because the vehicle wasn't purchased there. After receiving the recall notice the consumer's rv had a sudden blowout on the right rear tire. …”
NHTSA complaint #10053543, filed 2004-01Other Monaco Coach models
45 complaintsMonaco Coach Cayman
29 complaintsMonaco Coach Lapalma
16 complaintsMonaco Coach Windsor
14 complaintsMonaco Coach Monaco
12 complaintsMonaco Coach Dynasty
5 complaintsMonaco Coach Diplomat Le
5 complaints
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 29, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate. Methodology