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2004 Monaco Coach Diplomat

Owner reports · Recalls · Investigations

Limited comparison data

There is not enough comparable history to draw a useful model-year comparison.

About this comparison →
4Owner complaints

Model-year median: 2

1Recall campaigns

View recall details →

0Investigations

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How this year compares

Owner complaints by model year

Other model years Selected year
6
20012
20024
20041
20054
20061
2007
Compare all Diplomat years →

Counts vary with age, sales and reporting. They are not failure rates.

What owners reported most

Electrical System
2Service Brakes, Hydraulic
2Structure
2Visibility
2Equipment
1
All reported categories
Seats
1

Tap a category to read its complaints. One report may name several components.

When problems were reported

Mileage at the reported incident

Limited mileage data: 3 of 4 reports include usable mileage. There isn’t enough coverage to show a useful chart.

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

What to inspect

Issues worth paying extra attention to based on owner reports.

  • Electrical System. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Service Brakes, Hydraulic. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Structure. Review the 2 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

0 crash reports0 fire reports0 injury reports

Equipment complaints

1 reports
Clear category filter
Mileage unknown · Mar 25, 2005
Electrical SystemEquipmentService Brakes, Hydraulic

DIPLOMAT 40PDQ 2004 MOTOR HOME, THE SLIDE WAS OFF CENTER AND STRIPS WERE NOT LINED UP PROPERLY. *BF THE SLIDE RIDES TO HIGH AND CAUSES SO MUCH WIND NOISE THAT THE CONSUMER WAS UNABLE TO HEAR OUTSIDE TRAFFIC. A GAP UNDER THE WINDOW ALLOWED WATER TO COMING INTO THE COACH. THE CAPTAIN DRIVER SEAT STARTED COMING APART AT THE PE…

Read full complaint

DIPLOMAT 40PDQ 2004 MOTOR HOME, THE SLIDE WAS OFF CENTER AND STRIPS WERE NOT LINED UP PROPERLY. *BF THE SLIDE RIDES TO HIGH AND CAUSES SO MUCH WIND NOISE THAT THE CONSUMER WAS UNABLE TO HEAR OUTSIDE TRAFFIC. A GAP UNDER THE WINDOW ALLOWED WATER TO COMING INTO THE COACH. THE CAPTAIN DRIVER SEAT STARTED COMING APART AT THE PEDESTAL. WHEN APPLYING THE BRAKES SMOKE BILLOWED FROM THE REAR PASSENGER'S SIDE WHEEL. THE AIR CONDITIONER/HEAT PUMP KICKED THE CIRCUIT BREAKER. THE WINDSHIELD LEAKED IN THE CENTER ONTO THE DASH. CB GROUND PROBLEM. THE WASHER AND DRYING DID NOT WORK PROPERLY. THE HOLDING TANK WOULD NOT REGISTER PROPERLY. MANY ATTEMPTS HAVE BEEN MADE TO REPAIR THE COACH BUT NONE HAVE BEEN SUCCESSFUL. THE CONSUMER WOULD LIKE A FULL REFUND OF ALL MONEY PLUS ATTORNEY FEES OR A NEW COACH. NM

NHTSA ODI #10115850

Official recalls

1

04V441000 · Engine And Engine Cooling:engine:diesel

Sep 13, 2004

ON CERTAIN MOTORHOMES EQUIPPED WITH CUMMINS ENGINES, OIL CAN LEAK INTO THE ENGINE COMPARTMENT FROM A CRACK IN THE CUP PLUG.

Consequence & remedy

Consequence: OIL LEAKAGE ON A HOT ENGINE CAN RESULT IN AN ENGINE COMPARTMENT FIRE, POSSIBLY RESULTING IN INJURIES.

Remedy: CUMMINS IS CONDUCTING THE OWNER NOTIFICATION AND REMEDY FOR THIS CAMPAIGN. CUMMINS WILL INSTALL A STEEL CUP PLUG BOSS CAP TO ALL AFFECTED ENGINES. OWNERS SHOULD CONTACT CUMMINS CUSTOMER ASSISTANCE CENTER AT 1-800-343-7357 OR MONACO AT 1-800-685-6545.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

0

No exact-year investigations in this snapshot.