1986 Gmc C6 problems

Common 1986 Gmc C6 problems

The 1986 GMC C6 is known for various issues, primarily related to its engine, transmission, electrical system, and interior components. Here are some of the most common problems reported by owners:

• Fuel Injection Problems: Fuel injectors are a common issue on early model C4 Corvettes, including the 1986 GMC C6. The most common failure is an electrical short in the injector itself, which can cause the entire injector bank to malfunction. This failure can be severe enough to prevent the vehicle from starting.

• Intake Manifold Leaks: The intake manifolds are known to develop leaks, particularly around the corners and on the flat side of the manifold. These leaks can result in both coolant and oil loss, potentially causing engine damage or requiring costly repairs.

• Transmission (Automatic) Problems: The transmission overdrive can engage erratically due to a faulty control assembly, which can prevent the transmission from shifting into higher gears. Automatic transmissions may also exhibit difficult or hard shifting. The ABS system is known to fail, causing brakes to lock up and resulting in erratic pulsating in the braking system.

• Interior Issues: The instrument panel is known to flicker on and off, especially while the car is idling. The fuel gauge may fluctuate, resulting in possible stall conditions from engine fuel starvation. Shoulder harness/driver & passenger restraint systems can fail during impact/crash conditions, with the shoulder harness failing when the anchoring system breaks and seat belt retractors locking up, preventing the seat belts from being extendable/usable.

• Electrical Issues: The Vehicle Anti-Theft System (VATS) can cause various electrical issues, including difficulty starting the vehicle and erratic acceleration. The VATS system was introduced in 1986 and can cause issues with the electrical system, particularly when the vehicle is not properly maintained or repaired.

• C6 Transmission Troubles: The C6 transmission is known for various troubles, including leaking oil seals and failed RTV gaskets. These issues can lead to significant leaks, potentially causing damage to the transmission or requiring costly repairs. Additionally, the torque converter may be shot or partially empty, requiring replacement.

These issues are not an exhaustive list of all possible problems with the 1986 GMC C6, but they are some of the most commonly reported issues by owners. Proper maintenance and regular inspections can help prevent many of these issues, but some may require significant repairs or replacement of components.

What are common C6 transmission problems?

Common problems dealt with on a daily basis include:

It skips a gear. There is a delayed transmission engagement or it will not engage forward or in reverse. The transmission slips in forward and reverse and a whining noise comes from the front pump or torque converter area.

Is the Ford C6 a good transmission?

The Ford C6 transmission remains a dominant force in drag racing today, especially when equipped with manual valve bodies, transbrakes, and some units utilizing air-shifting technology. Its robust reputation makes it a favorite in off-road applications, known for its near-indestructible nature.

What years of C6 to avoid?

Quick Answer - Avoid C6 Corvette Year Models 2005, 2006, 2007, 2009, and 2013. The C6 Corvette was only on the market from 2005-2013, so there aren't too many models to analyze. However, it's clear which ones are better than the others. We recommend staying away from the 2005, 2006, 2007, 2009, and 2013 models.

How reliable are C6?

Its sturdy frame, well-designed chassis, and reliable engine have contributed to its enduring reputation. Owners and enthusiasts often praise the C6 for its resilience, as many models have aged gracefully with proper maintenance and care.

What are common C6 transmission problems?

Common problems dealt with on a daily basis include:

It skips a gear. There is a delayed transmission engagement or it will not engage forward or in reverse. The transmission slips in forward and reverse and a whining noise comes from the front pump or torque converter area.

Is the Ford C6 a good transmission?

The Ford C6 transmission remains a dominant force in drag racing today, especially when equipped with manual valve bodies, transbrakes, and some units utilizing air-shifting technology. Its robust reputation makes it a favorite in off-road applications, known for its near-indestructible nature.

What is the spec of the C6 transmission?

A stock C6 features a 2.40:1 (First), 1.40:1 (Second), and 1:1 (Third) setup from the factory. A new wide-ratio gearset is installed providing a numerically greater First gear of 2.72:1 followed by a 1.54:1 Second gear, which finally leads into the standard 1:1 Third gear ratio.

Which year C6 to avoid?

With over 520 owner complaints and six recalls, the C6 generation of the Corvette had a rough debut. And so, the 2006 Corvette is better avoided.

1986 Gmc C6 car problems categorized by type of issue

After analyzing all complaints sent to the NHTSA and researching popular Gmc C6 problems, we found that the most common problems with these 2023 model year vehicles are:

• Electrical system problems

The graph below shows statistics for all 1986 Gmc C6 vehicle components and the number of complaints received.