1978 Cadillac Deville problems

General information about Cadillac-Deville
Overview of popular issues
Analysis of common problems
Сomplaints list
Recalls list

The Cadillac DeVille is a model name used by Cadillac over eight generations, originally used to designate a trim level of the 1949 Cadillac Series 62 and later to designate a standalone model in the brand range. The last model marketed specifically as a DeVille was the 2005 full-size sedan, at the time, Cadillac's largest model.

For 2006, the Deville nameplate was retired, when the model line was carried forward (with minor revisions) as the Cadillac DTS, using a nomenclature adopted by the Cadillac STS and CTS.

Early history

The name "DeVille" is derived from the French de la ville or de ville meaning "of the town". In French coach building parlance, a coupé de ville, from the French couper (to cut) i.e. shorten or reduce, was a short four-wheeled closed carriage with an inside seat for two and an outside seat for the driver and this smaller vehicle was intended for use in the town or city (de ville). An (unshortened) limousine or (in the United States) town car has a division between the passenger and driver compartments and if the driver's seat is outside it may be called a sedanca de ville or town car.

The first Cadillac "Coupe de Ville" was shown during the 1949 Motorama. It was built on a Cadillac Sixty Special chassis and featured a dummy air-scoop, chrome trim around front wheel openings, and a one-piece windshield and rear glass. The interior was black and trimmed in gray leather, including the headliner, to match the roof color. It was equipped with a telephone in the glove compartment, a vanity case and a secretarial pad in the rear armrest, power windows and highly decorative chrome interior trim. The prototype "Coupe de Ville" was used by GM President Charles E. Wilson until 1957 when he presented it to his secretary. At some time during this period it acquired a dark Vicodec roof. The prototype "Coupe de Ville" was found and restored in the 2010s; it was in a private collection in London, Ontario, Canada as of 2017.

The Cadillac Series 62 Coupe de Ville was introduced late in the 1949 model year. Along with the Buick Roadmaster Riviera, and the Oldsmobile 98 Holiday, it was among the first pillarless hardtop coupes ever produced. At US$3,496 ($44,768 in 2023 dollars ) it was only a dollar less than the Series 62 convertible, and like the convertible, it came with power windows standard. It was luxuriously trimmed, with leather upholstery and chrome 'bows' in the headliner to simulate the ribs of a convertible top. In its first year the Series 62 Coupe de Ville only sold 2,150 units. But 1950 sales more than doubled to 4507, and in 1951 sales more than doubled again to 10,241 exceeding the sales for the Series 62 Club Coupe that year. Also, in 1951, Coupe de Ville chrome script appeared on the rear roof pillar for the first time, to further distinguish it from the Series 62 Club Coupe.

In 1956 the Series 62 Coupe de Ville was joined by the Series 62 Sedan de Ville, Cadillac's first standard production 4-door hardtop. Similarly to the Coupe de Ville, it was also more expensive and more luxuriously trimmed than the standard 4-door Series 62. With 41,732 sold, it also easily outsold the Series 62 sedan in its very first year. Given their sales success, it was only natural that the Coupe de Ville and Sedan de Ville were moved to their own separate series in 1959, the Series 6300, being joined by a DeVille convertible in 1964.

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Common 1978 Cadillac Deville problems

The Cadillac DeVille, a classic car beloved around the world, was discontinued after 2005, meaning the ones we see on the roads today have been cruising for quite some time and could be prone to some problems. One such issue is related to the power window regulators, which can fail in Devilles dating back to the 1991 model year, causing the window to fall into the door and not roll back up.

Another common issue with the Cadillac DeVille, particularly in models dating back to 1990, is related to the heating, ventilation, and air conditioning (HVAC) system. Some of the HVAC door actuators can fail, resulting in incorrect delivery of air or air at the wrong temperature.

It is important to note that the information presented here is based on available data and may not cover all possible issues that could arise with a 1978 Cadillac DeVille. As with any vehicle, regular maintenance and inspections by a qualified mechanic are crucial to ensure the car remains in good working condition and to catch any potential issues before they become serious problems.

What years of DeVille to avoid?

Overheating and cracked engine blocks in Cadillac DeVilles

The popular 2000 and 2002 Cadillac DeVilles are prime casualties, with the engine tending to overheat due to a leaking head gasket. Alternatively, a water pump leak could be preventing your coolant circulating freely through your engine.

What motor was in a 1978 Cadillac?

425ci V8

The Coupe Deville is powered by Cadillac's 425ci V8 that outputs 180hp/320lb/ft and delivers power through a THM400 3-speed automatic transmission and factory differential with 2.28:1 gearing.

How long can a Cadillac DeVille last?

How Many Miles Does a Cadillac Last? A new Cadillac typically drives between 150,000 and 200,000 miles with proper maintenance. This translates to about 10 to 13 years for an average driver clocking 15,000 miles per year.

Are vintage Cadillacs reliable?

A premium American brand, Cadillacs are built to last, as proven by these classic models that will practically run forever. One of the most famous American luxury car brands on the planet has to be Cadillac.

What years of DeVille to avoid?

Overheating and cracked engine blocks in Cadillac DeVilles

What motor was in a 1978 Cadillac?

425ci V8

The Coupe Deville is powered by Cadillac's 425ci V8 that outputs 180hp/320lb/ft and delivers power through a THM400 3-speed automatic transmission and factory differential with 2.28:1 gearing.

How long can a Cadillac DeVille last?

Are vintage Cadillacs reliable?

1978 Cadillac Deville car problems categorized by type of issue

After analyzing all complaints sent to the NHTSA and researching popular Cadillac Deville problems, we found that the most common problems with these 2023 model year vehicles are:

Tires problems
Fuel system problems
Gasoline problems
Service brakes problems
Hydraulic problems

The graph below shows statistics for all 1978 Cadillac Deville vehicle components and the number of complaints received.

1978 Cadillac Deville complaints

The NHTSA has received 4 complaints about various vehicle components related to the 1978 Cadillac Deville.

2011-08-12

TIRES PROBLEM

Date Of Incident: 2011-07-02
Components: TIRES
Summary: JETZON INNOVATION TIRE, P225/75R15, DOT U9HH, RCJ, 5110, D121, RADIAL DENSION 0341, 44210-1, R25502. THIS TIRE WAS MOUNTED AND IMMEDIATELY SEPARATED WHEN PARKED IN MY GARAGE AT HOME. THE OBVIOUS PROBLEM IS THE RUSTED STEEL IT WAS MANUFACTURED ON AND THE LACK OF ADHESION TO IT. I INFORMED THE COMPANY AND WAS TOLD IT WAS CAUSED BY MOUNTING AND WOULD NOT BE REPLACED. I AM 100% SURE THIS TIRE DEFECTIVE AND ANYONE MOUNTING THIS TIRE WOULD HAVE EXPOSED THE DEFECT. THIS TIRE WAS NOT EXPOSED TO THE ELEMENTS AND THE RUBBER AROUND THE RUSTED STEEL RIM BELT APPEARS TO HAVE DRY ROT LIKE CRACKS. I HAVE THE TIRE AND PHOTO'S TO SEND AT YOUR REQUEST. *TR UPDATED 12/15/11

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1997-06-24

FUEL SYSTEM, GASOLINE PROBLEM

Date Of Incident: 1997-05-01
Components: FUEL SYSTEM, GASOLINE
Summary: FUEL LEAK DUE TO A PUNCTURED FUEL LINE. *AK

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1996-03-04

TIRES PROBLEM

Date Of Incident: 1996-03-04
Components: TIRES
Summary: SEARS TIRE BLOWOUT. *SD

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1995-08-21

SERVICE BRAKES, HYDRAULIC PROBLEM

Date Of Incident: 2024-11-24
VIN: 6D69S8Q2357
Components: SERVICE BRAKES, HYDRAULIC
Summary: THE BRAKE HYDRAULIC CONTROL VALVE FAILED ON A MODULE THERE ARE NO BRAKE . TT

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1978 Cadillac Deville recalls

The National Highway Traffic Safety Administration (NHTSA) has issued 4 recalls for different components of the 1978 Cadillac Deville.

1979-05-04

Manufacturer: GENERAL MOTORS CORP.
Components: VEHICLE SPEED CONTROL:ACCELERATOR PEDAL
Summary: THE INVOLVED VEHICLES WERE BUILT WITH AN ACCELERATOR PEDAL HAVING AN EXTENSION, OR RUBBER FLAP, AT THE BOTTOM OF THE PEDAL. THIS PEDAL FLAP COULD BE INADVERTENTLY DISPLACED BY A FLOOR COVERING AND WEDGED UNDER THE ACCELERATOR PEDAL IN A MANNER THAT CAN INFLUENCE THE THROTTLE SETTING AND INCREASE THE ENGINE IDLE RPM.
Remedy: THE DEALER WILL REMOVE THE RUBBER FLAP FROM THE ACCELERATOR.

1978-08-30

Manufacturer: GENERAL MOTORS CORP.
Components: UNKNOWN OR OTHER
Summary: IF PAPER OR OTHER COMBUSTIBLE MATERIALS ARE PLACED IN THE INSTRUMENT PANEL ASHTRAY RECEPTACLE, THEY COULD BECOME IGNITED AND FLAMES FROM THE FIRE MAY REACH THE INTERIOR OF THE INSTRUMENT PANEL.
Remedy: OWNER WILL BE SENT A METAL HEAT SHIELD TO BE INSTALLED ABOVE THE INSTRUMENT PANEL, EITHER BY THE OWNER OR BY THE DEALER.

1977-11-16

Manufacturer: GENERAL MOTORS CORP.
Components: WHEELS:LUGS/NUTS/BOLTS/STUDS
Summary: THE REAR WHEEL MOUNTING BOLTS ON THE AFFECTED VEHICLES, ARE BRITTLE AND THEREFORE MAY FRACTURE. THIS BRITTLENESS IS DUE TO IMPROPER HEAT TREATMENT DURING MANUFACTURE. IF THE BOLTS BREAK, THE TIRE AND WHEEL ASSEMBLY MAY SEPARATE FROM THE VEHICLE.
Remedy: DEALER WILL INSPECT AND, IF NECESSARY, WILL REPLACE DEFECTIVE BOLTS ON ALL AXLES AND THE TEN REAR AXLE WHEEL MOUNTING BOLTS, FREE OF CHARGE.

1977-09-26

Manufacturer: GENERAL MOTORS CORP.
Components: VISIBILITY:WINDSHIELD WIPER/WASHER
Summary: SOME OF THE INVOLVED VEHICLES FAIL TO CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 104, "WINDSHIELD WIPING AND WASHING SYSTEMS". THE WINDSHIELD WASHER BOTTLE ON THE INVOLVED VEHICLES MAY CRACK AND ALLOW WASHER FLUID TO DRAIN OUT.
Remedy: DEALER WILL INSPECT THE WASHER BOTTLE AND, IF NECESSARY, REPLACE IT WITHOUT CHARGE TO OWNER.

Additional sources

More sources of information about 1978 Cadillac Deville problems:

Opinion wanted on purchase of 1978 or 1979 Coupe DeVille ...

https://www.cadillacforums.com/threads/opinion-wanted-on-purchase-of-1978-or-1979-coupe-deville.269113/

Sep 4, 2012 ... The 425 engine is a very formidable powerhouse, very enduring, and reliable. High mileage, may uncover a few problems, but for the most part, ...

1978 Cadillac DeVille - Issues when starting - Maintenance/Repairs ...

https://community.cartalk.com/t/1978-cadillac-deville-issues-when-starting/181553

Dec 30, 2021 ... I take it that is a carbureted vehicle possibly an issue with a choke or choke pull offs, if it is a general motors four barell quadrajet, ...

1978 RWD Seville | Cadillac Owners Forum

https://www.cadillacforums.com/threads/1978-rwd-seville.174215/

Jul 10, 2009 ... Fuel pumps are somewhat common as well as the injectors themselves. The weak link in this system is the DELCO (GM) wiring harnesses. Over time ...

Fuel Injection-Problems? 1978-1979.

https://forums.cadillaclasalle.club/index.php?topic=130013.0

Apr 3, 2014 ... The EFI option on the 75-79/80ish Cadillac's was never that common except on the 76-80 Seville where it was standard equipment. So you take a ...