1978 Pontiac Bonneville problems

Common 1978 Pontiac Bonneville problems

The first generation Pontiac Bonneville, produced from 1961 to 1964, faced several engine-related problems. One of the most common issues was oil leaks, which could be caused by worn or damaged gaskets, seals, or other engine components. These leaks could lead to significant engine damage if left unaddressed.

In the second generation of the Pontiac Bonneville, produced from 1977 to 1979, several electrical issues were reported by owners. One of the most common problems was related to the ignition system's wiring, which could cause the car to stall or fail to start. This issue was often caused by faulty wiring and could result in a fire if left unaddressed. Additionally, the power windows were known to malfunction, often due to issues with the window regulator. This could cause the windows to become stuck in the open or closed position, or fail to move at all. Some drivers reported having to replace the entire window regulator assembly to resolve this issue. Furthermore, the Bonneville of this generation was equipped with an electronic dashboard display that could fail, causing the gauges and warning lights to stop working. This issue was often due to a faulty printed circuit board and could be expensive to repair.

In the seventh generation of the Pontiac Bonneville, produced from 1987 to 1991, several engine-related problems were reported by owners. One of the most common issues was related to the ignition coil, which could cause a misfire or no-start condition. This problem was often caused by the coil's failure due to heat and vibration. Some Bonneville owners also reported issues with the fuel injectors, which could become clogged or fail, leading to poor engine performance, rough idling, and even stalling. Additionally, some models had issues with the engine's crankshaft position sensor, which could cause the car to stall unexpectedly. Lastly, some drivers experienced problems with the engine's timing chain, which could stretch and cause the engine to run poorly or not at all. If this issue is not addressed, it could lead to serious engine damage.

In summary, the Pontiac Bonneville, particularly the first, second, and seventh generations, faced several common problems related to the engine, electrical system, and fuel injectors. These issues could be frustrating and expensive to repair, but most of them could be addressed through regular maintenance and proper care.

How reliable are Pontiac Bonneville?

Bonneville owners have made 494 complaints over 16 model years. It ranks 10th in reliability out of 17 eligible Pontiac models. Our reliability rank is based on our PainRank™ system. A higher number means you can expect more significant problems.

What kind of engine does a Pontiac Bonneville have?

The Bonneville also had more powerful standard V8 engines than other full-sized Pontiacs, including the 389 cu in (6.4 L) or 400 cu in (6.6 L) V8s with four-barrel carburetors (power ratings of 303 to 340 hp (226 to 254 kW) depending on year) with many optional V8 offerings, such as the availability of the Tri-Power ( ...

What was the last year they made the Pontiac Bonneville?

2005

The Bonneville made its last stand in 2005 before being resigned to the history books. Pontiac itself lasted not much longer. But it was a great name, and Bonnevilles are great cars. There are still plenty of Pontiac lovers out there today—I'm one of them.

What was the first year of the Pontiac Bonneville?

The Bonneville nameplate appeared on the Star Chief lineup as a trim level, but in 1958 Pontiac introduced it as a separate, personal luxury coupe model.

How reliable are Pontiac Bonneville?

Bonneville owners have made 494 complaints over 16 model years. It ranks 10th in reliability out of 17 eligible Pontiac models. Our reliability rank is based on our PainRank™ system. A higher number means you can expect more significant problems.

How long can a Pontiac Bonneville last?

The bigger car ride, smaller car handling, full instrumentation and adult styling made the Bonnies an all-American car. The 3800 engine is very hard to fault and this car can easily last 200,000 miles with modest attention.

What size engine is in a 1978 Pontiac Bonneville?

The standard engine for Bonnevilles was the 140 hp 4.9L 301 CID V8, with Turbo Hydramatic transmission. Optional engines included a 170 hp, 4 BBL 350 and 180 hp, 4 BBL 400. The Pontiac 350 was replaced with the Chevy 350 in 1978, and the 400 was discontinued in 1979.

Was the Pontiac Bonneville a luxury car?

It entered the production lineup as a high-performance, fuel-injected luxury convertible version of the Star Chief in 1957, and was loaded with every available option as standard equipment to include leather upholstery, power adjustable front seat, power windows, power steering, power brakes and power convertible top ...

1978 Pontiac Bonneville car problems categorized by type of issue

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

• Tires problems
• Vehicle speed control problems
• Power train problems

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