NHTSA vehicle safety data

2004 Monaco Coach Diplomat Recalls & Complaints

The 2004 Monaco Coach Diplomat has 1 NHTSA recall campaign and 4 owner complaints on file as of November 3, 2026. Recall repairs are usually free at an authorized Monaco Coach dealer.

NHTSA recall and complaint data for the 2004 Monaco Coach Diplomat. Recall data is refreshed daily from NHTSA.

2004 Monaco Coach Diplomat owner complaints

Owners have filed 4 complaints with NHTSA about the 2004 Monaco Coach Diplomat, describing incidents dated April 5, 2004 to February 23, 2005.

Most-cited components

Electrical System 2 complaints
Service Brakes 2 complaints
Structure 2 complaints
Visibility/Wiper 2 complaints
Equipment 1 complaint
Seats 1 complaint

Newest complaints

ODI #10134035 · Filed October 18, 2005
DT: THE CALLER HAS A PROBLEM WITH THE FRONT ROADSIDE SLIDE ON THE MOTOR HOME. THEY HAD IT IN FOR REPAIR 8 DIFFERENT TIMES, AND IT STILL IS NOT FIXED. TO DATE THE ROADSIDE SLIDE IS UNSTABLE. THE SLIDE IS OFF CENTER, AND A PERSON CAN PUT THEIR HAND IN THE BOTTOM OPENING TO THE SIDE. THEREFORE, THE…
ODI #10124244 · Filed June 5, 2005
DEFROSTER NOT WORKING WINDSHIELDD ICED OVER WHEN DRIVING FROM SNOW. WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD INSUFFICIENT HOT WATER FLOW FROM REAR MOUNTED DIESEL ENGINE TO HEATER CORE ABOUT 37FT.
ODI #10122259 · Filed May 26, 2005
DEFROSTER NOT WORKING WINDSHIELD ICED OVER WHEN DRIVING FROM SNOW AND FREEZING RAIN.WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD.

Read all 4 complaints

MONACO/CUMMINGS/ENGINE BLOCK BOSS HOLE

NHTSA #04V441000 · Engine and Engine Cooling — Engine — Diesel · NHTSA notice

Reported September 13, 2004 · MONACO COACH CORPORATION

Potentially affected: 1,189 vehicles

Vehicles built December 12, 2003 – April 12, 2004 (per NHTSA)

Defect description

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

Safety consequence

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

Manufacturer 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.

Notes

CUSTOMERS CAN ALSO CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-888-DASH-2-DOT (1-888-327-4236).

try.vin has no NCAP crash-test rating on file for the 2004 Monaco Coach Diplomat. NHTSA rates some vehicles by body style — pickups by cab, vans by roof height — so check nhtsa.gov/ratings.

4 owner complaints have been filed with NHTSA for the 2004 Monaco Coach Diplomat.

Service Brakes, Hydraulic; Electrical System; Structure; Seats

ODI #10134035

Incident: April 5, 2004 · Filed: October 18, 2005

DT: THE CALLER HAS A PROBLEM WITH THE FRONT ROADSIDE SLIDE ON THE MOTOR HOME. THEY HAD IT IN FOR REPAIR 8 DIFFERENT TIMES, AND IT STILL IS NOT FIXED. TO DATE THE ROADSIDE SLIDE IS UNSTABLE. THE SLIDE IS OFF CENTER, AND A PERSON CAN PUT THEIR HAND IN THE BOTTOM OPENING TO THE SIDE. THEREFORE, THE SLIDE RIDES TOO HIGH AND CAUSES A LOUD WIND NOISE, A PERSON IS UNABLE TO HEAR THE TRAFFIC, AND THIS CAUSES DISTRACTION FOR THE DRIVER. ALSO, FEAR OF TURNING A CORNER AND CAUSING AN ACCIDENT. THE CAPTAIN'S DRIVER SEAT IS WOBBLING AT THE PEDESTAL, THE CALLER IS AFRAID THE SEAT WILL FALL OFF. WHEN APPLYING THE BRAKES THE RIGHT REAR SMOKES AND BELLOWS OUT AROUND THE WHEEL. THIS MOTOR HOME GCWR IS 39,300 POUNDS. THIS IS THE REASON WHY THIS MOTOR HOME IS UNSAFE. DIFFERENT DEALERS HAVE TRIED TO FIX THE ROADSIDE SLIDE, BUT NO ONE HAS BEEN ABLE TO DO SO. MANUFACTURER OFFERED THEM ANOTHER MOTOR HOME IF SHE PAID THE DIFFERENCE. THEY OFFERED THEM $5000.00 TO BRING IT TO ELKHART, INDIANA FOR REPAIRS. THE CALLER HAS HAD IT THERE TWO OTHER TIMES FOR THE SAME PROBLEM. THE CALLER SAID THE WORK WAS POORLY DONE UNDER THE WARRANTY. CALLER BELIEVES THIS IS A MANUFACTURER'S DEFECT. THE CALLER HAS HAD NUMEROUS ELECTRICAL PROBLEMS WITH MOTOR HOME.*AK *JB

Visibility

ODI #10124244

Incident: January 26, 2005 · Filed: June 5, 2005

DEFROSTER NOT WORKING WINDSHIELDD ICED OVER WHEN DRIVING FROM SNOW. WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD INSUFFICIENT HOT WATER FLOW FROM REAR MOUNTED DIESEL ENGINE TO HEATER CORE ABOUT 37FT.

Visibility

ODI #10122259

Incident: December 25, 2004 · Filed: May 26, 2005

DEFROSTER NOT WORKING WINDSHIELD ICED OVER WHEN DRIVING FROM SNOW AND FREEZING RAIN.WHEN STOPED DEFROSTER WILL OUTPUT ENOUGH HEAT TO MELT ICE. HEATER DEFROSTER IS SUB STANDARD.

Service Brakes, Hydraulic; Electrical System; Structure; Equipment

ODI #10115850

Incident: February 23, 2005 · Filed: March 25, 2005

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

Other Monaco Coach Diplomat model years

Check your 2004 Monaco Coach Diplomat VIN

Not every recall applies to every VIN in a given year. Enter the 17-character VIN from your Monaco Coach Diplomat at nhtsa.gov/recalls to see whether your specific vehicle has an unrepaired recall.

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