THE C4 CORVETTE - COMMON ISSUES
Of all the C4 Corvettes that were manufactured in it's twelve year reign, the 1984 Corvette has been identifed as the Corvette most plagued with problems. As this was the first year for the C4, there were a lot of "unknowns" that were identified and corrected by the beginning of the 1985 Corvette's production. Still, the 1984 Corvette is one of the most available and most affordable Corvettes in the used sports car market today.
The following list of common issues is intended for individual reference only, and may not reflect the specific issues of every 1984 Corvette. This information comes from a variety of sources including the NHTSA Defects Reports pages. While the intent of this page is to identify the common issues pertaining to the 1984 Corvette (including the Collectors Edition and the Grandsport,) it is not an all-inclusive list and should be used for reference only.
- When hot, the engine develops significant hesitation and a loss of power at high engine RPMs.
CROSSFIRE FUEL INJECTION
- The CrossFire Fuel Injected V-8 Engine has a hesitation/rough idle during acceleration. This is a very common issue with crossfire motors. The stumbling is probably from a weak fuel pump, low fuel pressure, dirty fuel filter, a dirty fuel pump sock or all the above.
ROUGH OR ERRATIC IDLE
- The erratic idle (both high and low) is more than likely caused by a vacuum leak. The main cause of this is that the top plate bolts become loose on the stock manifold and the throttle body shafts are worn out and leaking. The shafts go bad generally at around 50,000 miles and need to be bushed.
- Another item that often causes rough or erratic idle is a bad coolant temperature sensor. It is the Coolant Temperature Sensor that screws into the front of the crossfire manifold and has a small plastic shield around it. Replace the sensor with the newer two pin weather pack type. Do not wrap the threads with Teflon tape iwhen installing the new sensor as the threads/sensor body provides a ground through the block.
- A third, possible cause for rough or erratic idle is a bad oxygen sensor.
- Headlight motors are unreliable and commonly break, failing to open/close the headlight. The headlights are operated by an electric motor and have a worm gear, which rides on a plastic gear to turn the headlights up when in use. General Motors used small plastic bushings inside the gears to act as a buffer for vibration and to smooth the operation of the lights. Replacement of these bushings will often improve the operability of the headlights and eliminate the headlight issue.
- One common problem is the wipers on many of these cars are not properly adjusted to rest beneath the hood when turned off. When the wipers do not park correctly, they can scrape the black paint on the window trim, resulting in unsightly scratch marks on the trim and blemishing the aesthetic appeal of the vehicle.
- The 4+3 transmission is difficult to shift.
- The transmission is known to leak at the seals.
- Internal mechanical failure causes the transmission to tap when the vehicle is started in cold weather.
- Automatic transmission known to bind and stick in reverse. It exhibits difficulty shifting between gears during extreme cold conditions - most especially from 1st to 2nd. Also known to have slippage between 2nd and 3rd gears. Other problem areas with the automatic transmission include difficulty shifting into reverse and the overdrive tends to to make clunking noise when engaged/disengaged.
- Rear end of the car is noisy and is known to leak fluid.
- Independent front suspension failure causes vehicle to have poor directional control and to wander when it goes over bumps in the road.
POWER STEERING/STEERING COLUMN/GEARBOX
- Steering column failure results in poor directional control and wandering on smooth roads.
- At times, steering seems to bind when steering wheel is being turned indicating/possibly causing severe damage to the gearbox.
- Power steering reservoir cap leaks fluid throughout the engine compartment.
- Rack and pinion steering locks up during cold starts or ambient temperatures. It has been reported that this particular rack and pinion failure is caused by defective neophene seals. As vehicle reaches operating temperature, the problem appears to correct itself.
- OEM Catalytic converters are known to fail, causing a "rotten egg" odor in the car.
- Front brake mounting plates have been known to fracture, causing the caliper to rotate forward and jam against the dust shield. This, in turn, can cause significant brake failure resulting in other hazardous conditions including potential severe damage to the car as a whole.
- Removable roof top leaks around weatherstipping seal.
- Fiberglass body is known to experience severe cracking resulting from stress on the body due to lack of structural braces.
- The dashboard is known to short-circuit, resulting in intermittent operation of the dashboard. The result is a flashing dashboard - or - a dimly lit or a completely blacked out dashboard. The main reasons for this issue are: poor electrical grounds, corrosion on the terminals, or burnt out lightbulbs. To resolve this issue, one of three possible solutions exist. These are:
1.) One or, or as many as all four halogen 882 light bulbs may need to be replaced. 2.) Clean the 882 light bulb sockets. 3.) Check ground connections for dashboard to ensure proper grounding.
- The additional power draw by the electric dashboard causes premature battery failure.
- Driver side door panels commonly crack on the inside as the direct result of poor holding design.
- The power windows on most C4 Corvettes tend to operate excessively slow. After 1986, a replacement motor was introduced. However, there are now a number of after-market options available to replace the factory windows.
- Misalignment of the window in its track causes scratching to occur on the glass surface of the window.
- Passenger slide window is known to slide/fall down in its track at will.
POWER SEAT MOTORS
- Power seat motors are known to fail, impairing the operator's ability to change the position of the seat.
- Rear defogger often fails to work.
- A number of engine fires has been reported by 1984 Corvette owners. When conisdering purchasing a 1984 Chevy Corvette, identify if the engine has caused this type of fire.
- Excessive squeaks and rattles throughout the car.
- Seatbelt warning chimes often fail to operate.
- Cruise control cable failure is known to cause engine runaway.
NOTE: If you've experienced a specific problem not referenced here, please contact us at firstname.lastname@example.org and tell us about it.
DISCLAIMER: While Corvsport.com makes every effort to ensure that this information is complete and accurate, you should always consult the manufacturer of your vehicle if you have a specific issue or question.