While there were few who questioned the technological superiority of the 1984C4 over earlier generations of Corvette, it’s lack of robust horsepower and outright performance left many questioning this new version of America’s most beloved sports car. Chevrolet listened to the criticisms and quickly began to revamp the Corvette platform to become a more competitive contender.
After all, the U.S. economy was beginning to rebound from the recession that had plagued the United States (and indeed, the entire world) in the early eighties. The cost of fuel dropped as the world economy saw an oil glut – the direct result of global conservation after the 1970’s energy crisis. This new oil surplus (and corresponding drop in fuel prices) quickly brought potential consumers who were once more looking for big, powerful, performance cars.
In addition, Ronald Reagan and his administration had convinced Japanese automakers to voluntarily limit their car exports to the United States via the Voluntary Restraint Agreement (VRA), which had the intended result of encouraging American consumers to purchase American-made automobiles.
When the C4 Corvette returned for a second year in 1985, it did so with some much needed improvements.
Gone forever was the Cross-Fire Injection System that had been introduced as part of the C4 only a year earlier (and had managed to survive for only a single production year on the C4 platform.) Replacing this awkward and somewhat uninspired system was a new “Tuned Port Injection” fuel delivery system – a system that was essentially the German Bosch fuel-injection system which featured a revised intake manifold. This new system provided an individual fuel injector for each engine cylinder, featured tuned runners and included a new mass air flow sensor, all of which would aid in the car’s improved performance.
In fact, the introduction of the new “Tuned-Port Injection” system, along with a half point compression increase (9.5:1) improved the engine output by 25 horsepower, pushing the engine to a total of 230 Brake Horsepower (BHP) at 4,000 RPM. Similarly, the engine’s torque was increased by 40lbs/ft, taking it to 330lbs/ft at 3,200 RPM (versus the former 290lbs/ft at 2,800 RPM found on the 1984C4 model.) The fact that these changes were so extensive, and that they had dramatically improvedCorvette’s performance, motivated Chevrolet to use an entirely new designation for the engine – and thus the L98 was born
Just as the engine had received an overhaul, the Doug Nash 4+3 Overdrive manual transmission underwent a less radical, but equally important, upgrade to help improve its performance. For the 1985 model, the 4+3 received a heavy-duty 8.5-inch differential ring gear (an increase from the 7.9 inch ring gear in the 1984 model) for extra longevity. As a convenience factor, the transmission’s override button was relocated from the console to atop the shift knob. Further, the transmission’s onboard computer was reprogrammed to make the overdrive function less intrusive. Additionally, the electronics governing the lockup torque converter clutch were also revised.
Another item that, General Motors sought to resolve in the 1985 Corvette was the car’s harsh, and often unforgiving, ride. Responding to the many complaints they received, Chevy responded by softening both the spring and shock rates. This modification was inclusive on all Corvettes – even those suited with the Z51 suspension package (an option in 1985.)
With regard to the Z51 package, other suspension changes were introduced as well. This option now included larger fore and aft stabilizer bars which helped to offset total roll stiffness after GM introduced the softer suspension calibrations. Further, the package included wider, 9.5 inch wide tires to be mounted in the front (as well as the rear) of the car. Also included were Delco-Bilstein gas-pressurized shocks and a revised heavy duty cooling system. The Delco-Bilstein shocks were also offered as a separate option on the base level Corvette.
Just as General Motors had made improvements to the steering and suspension systems, GM engineers continued to take great interest in how the C4 Corvette handled. After all, the C4 Corvette had been spawned off the design criteria that what it lacked in horsepower would be compensated for in car structure, design and drivability. As production of the 1985 Corvette progressed, the Z51 suspension package option continued to undergo revisionary design work, a process that was led by GM engineer John Heinricy. His intent was to develop the Corvette to a point where it could be classified as a“showroom stock GT car.”
Interestingly, the changes that Heinciry made to the suspension resulted in the 1985 Corvette being lowered ¾ of an inch. This change, though nearly indistinguishable to the naked eye, reduced the drag coefficient to 0.33. Further, when geared with the 3.07:1 rear axle, allowed the 1985 Corvette to reach 150 miles per hour. Of course, achieving 150 miles per hour still required the upgraded rear end, but overcoming this particular speed barrier had been accomplished and solidified the C4 Corvette as a more serious sports car in the eyes of performance enthusiasts.
DID YOU KNOW: The exterior styling of the C4 Corvette was completely unchanged from 1984 to 1985 with the exception of the side badges on the front fenders of the car, which were changed from “Cross-Fire Injection” to “Tuned-Port Injection”. Because of the harsh ride experienced by owners of the 1984 Corvette, the spring rates were decreased in 1985 – a 26% reduction in the front springs, a 25% reduction in the rear.
As GM, engineers set out to have Corvette achieve higher speeds, it was determined that the steering caster angle should be increased by one degree (to a total of four degrees) to produce better straight-line stability. Similarly, the braking system was bolstered to produce greater braking power by the addition of a larger brake master cylinder and brake booster as well as different brake pad linings. These minor, but significant changes were just a few of the many considerations that GM engineers were making when responding to the criticisms they had received on the 1984 Corvette
While the appearance of the C4 Corvette was well received by critics and enthusiasts alike, there were still several small refinements that were made to its cosmetic appearance. The interior received a minor facelift which included revised instrument graphics and optional leather upholstery for the more expensive Lear-Siegler Seats. Though subtle, these changes further solidified the overall aesthetic quality of the car. Additionally, Chevy engineers began seeking out and eliminating the sources of the rattles and squeaks that had been such a constant annoyance to consumers who had purchased the 1984 model.
Despite its many improvements, the 1985 Corvette was still met with a mix of praise and criticism. On one hand, they complimented its improved braking and road handling characteristics. At the same time, they criticized the revised short rack steering. In fact, automotive testers claimed that the steering was too quick for around-town use. Further, the ride was still deemed as being overly harsh despite the refinements that had been made to the suspension system. Ultimately though, the overall opinion of the 1985 Corvette was that General Motors had improved on their earlier efforts and had taken the C4 in the right direction.
In 1985, the Chevy Corvette sold for approximately half of the comparably equipped Porsche 928, yet was capable of handling/performing at the same level as the German Sportscar. In fact, when doing a performance comparison of the 1985 Corvette and the Porsche 928, the Corvette outran the Porsche and was named the “Fastest Car In America” after hitting top speeds of 150 miles per hour. The results of this survey, combined with the return of the Corvette to racing circuits in 1985, were so unsettling to the Porsche engineers that they bought two 1985 Corvettes, shipped them to Germany and took them apart in an attempt to determine what made them so quick!
Car and Driver magazine was among the automotive media that celebrated the new model’s improved automotive refinements. After sampling two Corvettes, one with an automatic transmission and the base suspension and one with the upgraded Z51 suspension and a manual transmission, they recorded results that were considered more than respectable for their time. The automatic ran a quarter mile time of just 14.1 seconds at 97 miles per hour. The manual version ran the quarter mile in just 14.4 seconds and reached a top speed of 95 miles per hour. Car and Driver went on to proclaim that the Corvette to be “America’s fastest production vehicle capable of 150 mile per hour top speed”. In less than two years time, General Motors had succeeded in improving the performance of the C4 to a point where it could rival the competition worldwide.
However, the cost of these improvements caused a sizable increase in the sell price of the 1985 Corvette. The cost of the C4 (base price) jumped from $21,800 in 1984 to $24,403 just a year later. As a result, the C4’s sales dropped dramatically, resulting in the lowest number of annual sales in more than ten years. Despite the decline in sales, General Motors knew that they were moving in the right direction with this new design, and continued to layout further design revisions which would help the Corvette gain greater success in the years to come.
One of the great challenges that was about to be set forth by General Motors was the development of an entirely new engine. After all, the current L98 350 cubic inch small-block V8, (with its cast iron block and its rocker operated valve gear), was nearly thirty years old and, despite the refinements of the fuel injection system at the beginning of the model year, was not the performance powerhouse that had become synonymous with earlier generations of Corvette. Still, Federal edicts of the day made the idea of reworking the generations old V8 into something more powerful an unlikely course of action. Despite that fact, it was in 1985 that GM made the decision to begin the fundamental reworking of the 350 small block – and would ultimately lead to the development of an all new V8 engine.
It was decided that the revised engine would have to be capable of returning the same fuel economy as the L98 engine but would have to achieve the performance levels of Ferrari, Aston Martin and Porsche. In the words of Chevrolet Chief Engineer Fred Schaafsma, this new engine (and the Corvette it would power) was to be “…the best performing production car in the world.” Ironically, that reworking would impact the future of Corvette for all time, giving birth to one of the greatest Corvettes ever – the ZR1.
Location of the Assembly Plant. 5 – Bowling Green, Kentucky
1XXXXX (Twelfth thru Seventeenth Digits)
Production Sequence Numbers.
The last six digits begin at 100001 and run thru 139729, accounting for each of the 39,729 Corvette Coupes built in 1985. Each Vehicle Identification Number (VIN) is unique to an individual car.
The Check digit is used to calculate the characters in the serial number and gives it a single digit code that can be used to verify the serial number is legitimate. (Note: The Check digit number varies depending on each specific VIN number.)
For all 1985 Corvettes, the Vehicle Identification Number was stamped on a plate on the inner vertical surface of the left windshield pillar visible through the windshield.
1985 Corvette Factory Options
Base Corvette Sport Coupe
Power Driver Seat
Sport Seats, Leather
Base Seats, Leather
Sport Seats, Cloth
Power Door Locks
Removable Transparent Roof Panel
Delco-Bilstein Shock Absorbers
Performance Axle Ratio
4-Speed Manual Transmission
California Emissions Requirements
AM-FM Stereo Cassette
AM-FM Stereo, Citizens Band
Stereo System, Delco-Bose
Heavy Duty Cooling
Performance Handling Package
Pear Window + Side Mirror Defoggers
Base Corvette Roadster (1YY07)
The base price of the 1985 Chevrolet Corvette Coupe without any optional equipment.
The 1985 Corvette saw the return of true fuel injection with the introduction of the Tuned-Port Fuel
Injection system that came standard with the more powerful L98 V-8 engine.
A 350 cubic inch, 230 horsepower engine, 4-speed automatic transmission, removable body-color roof panel, and cloth seats were included in the base price.
Power Driver Seat (AG9)
Optional, six-way, adjustable driver seat.
Sports Seat, Leather (AQ9)
Special sport seats that featured inflatable lumbar support and power-adjusted side bolsters.
The sports seat option, (which was available only in cloth in 1984), became available in leather as an interim 1985 option.
Leather seats sold in 1985 totaled 30,955 units, which included both the optional base seat in leather as well as the optional sport seat in leather.
Base Seats, Leather (AR9)
Leather cover option for the standard, base driver and passenger seats.
Sports Seat, Cloth (—-)
Special sport seats that featured inflatable lumbar support and power-adjusted side bolsters.
Optional cloth version of the AQ9 option.
Power Door Locks (AU3)
Electronic locking system that replaced standard, manual door locks.
Removable Transparent Roof Panel (CC3)
Single piece, glass roof panel that gives driver an “open air” feel while driving.
All 1985 Corvettes were designed with one-piece, lift-off roof panels and rear hatch windows.
For 1985, the removable glass roof panel was manufactured with stronger sun screening.
Two Tone Paint (D84)
Optional paint scheme that allowed buyers the option of three, different, two-tone paint combinations.
Options included Silver/Grey, Light Blue/Medium Blue, and Light Bronze/Dark Bronze.
Delco-Belstein Shock Absorbers (FG3)
Gas shock absorbers with valving revised for improved ride.
The FG3 option offered the Z51’s upgraded shocks without buying the full Z51 suspension package.
A joint venture between AC-Delco and premium shock manufacturer Bilstein, these stiffer shocks offered a firmer ride and improved handling characteristics.
Performance Axle Ratio (G92)
Optional performance axle ratio of 3.07:1.
Was only offered when the Corvette was ordered with an automatic transmission.
The actual “Performance Axle Ratio” varied from year to year. The G92 Option was available when ordering either the Corvette or the Camaro throughout the 1980’s and early ’90’s.
Cruise Control (K34)
Automatic electric cruise control with “resume” and “accelerate” options.
4-Speed Manual Transmission (MM4)
Optional manual transmission that was offered as a zero dollar upgrade.
A “4+3”, 4 speed manual transmission that was originally developed and built by Doug Nash Company.
The “4+3” transmission had overdrives in the top three gears for improved fuel economy.
In 1985, the 4+3 Manual Transmission came with a new, heavy duty 8.5 inch ring differential.
The manual transmission overdrive selector button was moved from the console to the shift knob itself.
Rear axle gear ratios for manual transmission models was 3.07:1.
California Emission Requirements (NN5)
Revised emission/exhaust components to meet California Emission standards
Radio Delete (UL5)
Optional removal of any stereo components from the Corvette.
AM-FM Stereo Cassette (UM6)
Electronically tuned stereo radio with cassette.
AM-FM Stereo, Citizens Band (UN8)
AM/FM stereo system with citizens band radio and hand held transmitter/microphone.
Stereo System, Delco-Bose (UU8)
Delco Bose AM/FM stereo radio with cassette.
Heavy Duty Cooling (V08)
Optional, three (3) core aluminum radiator.
Includes larger diameter transmission cooler.
Performance Handling Package (Z51)
Heavy Duty Steering and Suspension Upgrade for Improved Handling.
Included heavy-duty front and rear springs, shock absorbers, stabilizer bars and bushings, fast steering ratio, engine oil cooler, extra radiator fan (pusher), P255 / 50VR16 tires and directional alloy wheels (16 x 8.5 (front) and 16 x 9.5 (rear)).
Suspension rates were lowered in 1985 as a result of harsh ride criticisms from the previous model year.
Springs for the base suspension were softer by 26% in front and 25% in the rear. Springs included in the
Z51 option were 16% softer in the front and 25% softer in the rear.
To compensate for the spring change, larger diameter stabilizer bars were included with Z51 equipped models.
Rear Window + Side Mirror Defoggers (Z6A)
Components were equipped with heating elements (wire) for defogging.
The C4 Corvette used vertically run wire through it’s rear window to achieve proper and timely defogging.
1985 Corvette Recalls
Make: CHEVROLET Model: CORVETTE Model Year: 1985 Manufacturer: HONEYWELL INTERNATIONAL, INC. Mfr’s Report Date: MAY 19, 2006 NHTSA CAMPAIGN ID Number: 06E043000 NHTSA Action Number: N/A Component: FUEL SYSTEM, GASOLINE Potential Number of Units Affected: 88303
CERTAIN REPLACEMENT FUEL FILTERS, FRAM BRAND NAME P/N G3727, WITH DATE CODES X52911 THROUGH X60801 SEQUENTIALLY OR X600141 AND A MEXICO COUNTRY OR ORIGIN MARKING ON THE FUEL FILTER HOUSING MANUFACTURED FROM OCTOBER 18, 2005, THROUGH MARCH 21, 2006, SOLD FOR USE ON THE VEHICLES LISTED ABOVE AND ON CERTAIN SCHOOL BUSES. (TO SEE THE SCHOOL BUS ENGINE SIZES, CLICK ON “DOCUMENT SEARCH” AND THEN “BUS APPLICATIONS”). THE CONNECTOR ON THE FUEL FILTER WAS NOT MANUFACTURED TO HONEYWELL’S SPECIFICATION. AS A RESULT, THE O-RING MAY NOT SEAT CORRECTLY ON THE FUEL LINE.
THIS CONDITION MAY CAUSE AN INADEQUATE SEAL AT THE CONNECTION, POTENTIALLY LEADING TO A FUEL LEAK. IN THE PRESENCE OF AN IGNITION SOURCE, A FIRE COULD OCCUR.
HONEYWELL WILL NOTIFY OWNERS AND REPLACE THE FUEL FILTERS FREE OF CHARGE. THE RECALL BEGAN ON OCTOBER 18, 2006. OWNERS MAY CONTACT FRAM CUSTOMER SERVICE AT 1-800-890-2075 (OPTION 1).
THIS RECALL ONLY PERTAINS TO AFTERMARKET FRAM FUEL FILTERS AND HAS NO RELATION TO ANY ORIGINAL EQUIPMENT INSTALLED ON THE VEHICLES LISTED. CUSTOMERS MAY CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION’S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY: 1-800-424-9153); OR GO TO WWW.SAFERCAR.GOV.
Make: CHEVROLET Model: CORVETTE Model Year: 1985 Manufacturer: HONEYWELL INTERNATIONAL, INC. Mfr’s Report Date: OCT 19, 2007 NHTSA CAMPAIGN ID Number: 07E088000 NHTSA Action Number: N/A Component: EQUIPMENT Potential Number of Units Affected: 121680
CERTAIN HONEYWELL FRAM RACING BRAND HP4 AND HP8 OIL FILTERS THAT WERE MANUFACTURED FROM MAY 25, 2006, THROUGH SEPTEMBER 14, 2007, AND SOLD FOR USE AS REPLACEMENT EQUIPMENT FOR VEHICLES LIST ABOVE. THE AFFECTED FILTERS ARE MARKED WITH A DATE CODE A61451 THROUGH A72571 SEQUENTIALLY. THE DATE CODE AND PART NUMBER APPEAR ON THE FILTER HOUSING. FRAM RACING HP4 AND HP8 OIL FILTERS NOT BEARING A DATE CODE IN THIS RANGE ARE NOT AFFECTED BY THIS RECALL. THE GASKET OF THE OIL FILTER BECOMES MORE PLIABLE UNDER HIGH TEMPERATURES AND PRESSURES.
THIS CONDITION MAY CAUSE INADEQUATE SEALING AND LOSS OF ENGINE OIL, POSSIBLY RESULTING IN A FIRE.
HONEYWELL WILL REPLACE THE AFFECTED OIL FILTERS FREE OF CHARGE. THE RECALL BEGAN DURING NOVEMBER 2007. OWNERS CAN CONTACT FRAM CUSTOMER SERVICE TOLL-FREE AT 1-800-890-2075.
CUSTOMERS MAY CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION’S VEHICLE SAFETY HOTLINE AT 1-888-327-4236 (TTY: 1-800-424-9153); OR GO TO WWW.SAFERCAR.GOV.
Make: CHEVROLET Model: CORVETTE Model Year: 1985 Manufacturer: GENERAL MOTORS CORP. Mfr’s Report Date: AUG 26, 1991 NHTSA CAMPAIGN ID Number: 91V143000 NHTSA Action Number: EA90033 Component: SEAT BELTS:FRONT:ANCHORAGE Potential Number of Units Affected: 231833
UNDER CERTAIN VEHICLE OPERATIONS AND OCCUPANT USAGE CONDITIONS, THE SAFETY BELTS CAN LOCKUP OR JAM IN THE SAFETY BELT RETRACTOR.
IF LOCKUP OCCURS, IT IS IMPOSSIBLE TO PULL BELT OUT OF THE RETRACTOR. THE OCCUPANT OF A SEAT WITH AN UNUSABLE SAFETY BELT IS SUBJECT TO INCREASED RISK OF INJURY OR DEATH IN THE EVENT OF A SUDDEN STOP OR ACCIDENT.
Make: Chevrolet Model: Corvette Model Year: 1985 Manufacturer: General Motors Corp. Service Bulletin Number: 9313110 Date of Bulletin: Mar 01, 1993 NHTSA Item Number: 39547 Component: Visibility – Glass, Side/Rear
1985 Corvette Common Issues
The following list of common issues is intended for individual reference only, and may not reflect the specific issues of every 1985 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 1985 Corvette, it is not an all-inclusive list and should be used for reference only.
The engine may shut off after it reaches normal operating temperature. There are several possible items that could cause this. They include:
Bad Oil Pressure Switch – If this switch fails/does not detect oil pressure, it will cause the engine to shut off.
A Bad Distributor Module – the module may overheat, causing it to fail.
Fuel Pump Relay – A bad relay will cause the pump motor in the fuel tank to fail, causing ignition failure.
The Throttle Position Sensor.
Mass Air Flow Sensor
For both the Mass Air Flow Sensor and the Throttle Position Sensor, it is important to monitor voltage across/to each of these sensors. Improper voltage can adversely impact how these sensors operate and may cause engine ignition failure.
If the engine starts but will not continue running/idle, there are other items that may need to be considered as well. In many instances, a rough idle/stalling engine may be caused by dirty/damaged fuel injectors. Cleaning (and, if necessary, replacing) the fuel injectors may resolve this issue. Carbon build up in the throttle body can also cause the same symptoms. Cleaning the throttle body in conjunction with the injectors will eliminate many rough idle conditions.
If the engine will turn over but simply won’t run, the most common cause of this issue is a failed Computer/PROM. Located under the dashboard, the PROM controls the ignition/drive functions of the engine. Replacement PROMS are available from most aftermarket vendors.
Additionally, the L98 engines had problems maintaining idle due to the design and use of the IAC ( Idle Air Control Valve). To compensate for this issue, the idle speed needs to be adjusted to a minimum air rate of 500rpm.
The rear of the intake manifold is known to leak oil.
Erratic shifting is known to be an issue in the automatic transmission. A properly operating transmission should shift smoothly no matter what load is put on it.
The manual transmission is known to exhibit synchronizer problems. The shift points should transition smoothly with no need to “double clutch” or “coach” the transmission into changing gears.
The Dana Rear Axle/Differential is known to make a fair amount of noise.
Headlight Drive Motors
The drive motors that rotate the headlight assembly are known to fail. The headlight motor transmissions use nylon gears which fail over time.
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:
One or, or as many as all four halogen 882 light bulbs may need to be replaced.
Clean the 882 light bulb sockets.
Check ground connections for dashboard to ensure proper grounding.
Driver & Passenger Seats
Because of the high side rails on the lower edge of the driver and passenger doors, getting out of the Corvette can be difficult. As a result, the outside seat bolsters tend to fatigue, causing a number of issues – leather deterioration, tearing, structural fatigue of the bolster sub-assembly (padding).
1985 Corvette Maintenance Schedule
Follow Schedule 1 if your car is mainly operated under one or more of the following conditions:.
When most trips are less than 4 miles (6 kilometers)
When most trips are less than 10 miles (16 kilometers) and outside temperatures remain below freezing.
Idling for extended periods and/or low-speed operation such as found in delivery, police, rental or taxi operation.
Towing a trailer.
Operating in dusty areas.
Follow Schedule 2 only if none of the driving conditions specified in Schedule 1 apply.
Additional Maintenance and Lubrication
While Operating Your Vehicle
Automatic Transmission Shift Indicator Position – Make sure the indicator points to the gear chosen.
Horn Operation – Blow the horn occasionally to make sure it works. Check all button locations.
Brake System Operation – Be alert to abnormal sounds, increased brake pedal travel or repeated pulling to one side when braking. Also, if a brake warning light comes on or flashes, or the anti-lock (if equipped) comes on or remains on, something may be wrong with part of the braking system. Have it inspected and repaired at once.
Exhaust System Operation – Be alert to any changes in the sound of the system or any smell of fumes. These are signs the system may be leaking or overheating. Have it inspected and repaired at once. Also see “Engine Exhaust Gas Caution (Carbon Monoxide)” and “Catalytic Converter” in your Owner’s Manual.
Tire and Wheel Operation – Be alert to a vibration of the steering wheel or seat at normal highway speeds. This may mean a wheel balance is needed. Also, a pull right or left on a straight, level road may show the need for a tire pressure adjustment or wheel alignment.
Steering System Operation – Be alert to changes in steering action. An inspection is needed when the steering wheel is harder to turn or has too much free play or if unusual sounds are noted when turning or parking.
Headlight Aim Operation – Take note of light pattern occasionally. If beam aim doesn’t look right, headlights should be aligned.
At Each Fuel Fill:
Engine Oil Level Check – Check engine oil level and add if necessary. See your Owner’s Manual for further details. NOTE: A large loss of oil in this system may indicate a problem. Have it inspected and repaired at once.
Engine Coolant Level and Condition – Check engine coolant level in coolant reservoir tank and add if necessary. Replace if dirty or rusty. See your Owner’s Manual for further details. NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Windshield Washer Fluid Level Check – Check washer fluid level in container and add if necessary.
At Least Monthly:
Tire Pressure Check – Keep pressures as shown on Tire Placard on the driver’s door (include spare unless it is a stowaway). Pressure should be checked when tires are “cold”.
Light Operation Check – Check operation of license plate light, side-marker lights, headlights including high beams, parking lights, taillights, brake lights, turn signals, backup lights, instrument panel and interior lights and hazard warning flashers.
Fluid Leak Check – After the car has been parked for a while, inspect the surface beneath the car for water, oil, fuel or other fluids. Water dripping from the air conditioning system after use is normal. If you notice fuel leaks or fumes, the cause should be found and corrected at once.
At Least Twice A Year (for example: Every Spring and Fall):
Power Steering Pump Fluid Level Check – Check power steering pump fluid level in accordance with Owner’s Manual instructions and keep at proper level. NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Brake Master Cylinder Reservoir Fluid Level Check – Check fluid and keep at proper level. NOTE: A low fluid level can indicate worn disc brake pads which may need to be serviced. NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Clutch System Service – Manual Transmissions – For cars equipped with hydraulic clutch systems, check the reservoir fluid level and add fluid as required. All others, check clutch pedal free travel and adjust as necessary. See your Owner’s Manual for further detail. NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Each Time Oil Is Changed:
Automatic and Manual Transmission/Transaxle Fluid Level Check – Check transmission/transaxle fluid level and add as required. If equipped with manual transmission – check fluid in the overdrive unit and add as required. NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Tire and Wheel Inspection and Rotation – Check tires for abnormal wear or damage. Also, check for damaged wheels. To equalize tire wear and obtain maximum tire life, it is suggested that tires be rotated at 7,500 miles (12,500 kilometers) followed by 15,000 miles (25,000 kilometers) thereafter. See “Tires” in owners manual for further information.
Brake Systems Inspection – For convenience, the following should be done when wheels are removed for rotation: Inspect lines and hoses for proper hookup, binding, leaks, cracks, chafing, etc. Inspect disc brake pads for wear and rotors for surface condition. Also inspect drum brake linings for wear and cracks (if applicable). Inspect other brake parts, including drums, wheel cylinders, parking brake, etc. at the same time. Check parking brake adjustment. INSPECT BRAKES MORE OFTEN IF DRIVING HABITS OR CONDITIONS RESULT IN FREQUENT BRAKING.
Steering, Suspension and Front Drive Axle Boot and Seal Inspection – Inspect front and rear suspension and steering system for damaged, loose or missing parts, signs of wear or lack of lubrication. Inspect power steering lines and hoses for proper hookup, binding, leaks, cracks, chafing, etc. (On cars equipped with manual steering gear, check for seal leakage.) Replace seals if necessary.
Exhaust System Inspection – Inspect complete system. Inspect boy near the exhaust system. Look for broken, damaged, missing or out-of-position parts as well as open seams, holes, loose connections or other conditions which could cause a heat build up in the floor pan or could let exhaust fumes seep into the trunk or passenger compartment.
Throttle Linkage Inspection – Inspect for interference, binding , damaged or missing parts.
Engine Drive Belts Inspection – Inspect all belts for cracks, fraying and wear. Adjust or replace as needed.
Rear Axle Service – Check gear lubricant level and add if needed. Cars equipped with limited-slip differential should have gear lubricant and any required additives drained and refilled at 7,500 miles (12,500 kilometers). See your Owner’s Manual. IF YOU USE YOUR CAR TO PULL A TRAILER, CHANGE GEAR LUBRICANT EVERY 7,500 MILES (12,500 KILOMETERS). NOTE: A large loss in this system may indicate a problem. Have it inspected and repaired at once.
Power Antenna – Clean and then lubricate power antenna mast. The proper lubricant should be used.
At Least Once A Year:
Lap and Shoulder Belts Condition and Operation – Inspect belt system, including webbing, buckles, latch plates, retractors, guide loops and anchors.
Seatback Latch and Recliner Operation – Be sure seatbacks latch using mechanical latches. Make sure the recliner is holding by pushing and pulling on the top of the seatback while it is reclined. See your Owner’s Manual for seat operating information.
Spare Tire and Jack Storage – Be alert to rattles in rear of car. Make sure the spare tire, all jacking equipment, any tire inflator and any covers or doors are securely stowed at all times. Oil jack ratchet or screw mechanism after each use.
Key Lock Service – Lubricate key lock cylinder at least annually.
Body Lubrication Service – Lubricate all body door hinges including the tailgate (if equipped). Also lubricate the body hood, fuel door and rear compartment hinges and latches including interior glove box and counsel doors, and any folding seat hardware.
Starter Safety Switch Operation – CAUTION: Before performing the following safety switch check, be sure to have enough room around the car. Then, firmly apply both the parking brake (see your Owner’s Manual for procedure) and the regular brakes. Do not use the accelerator pedal. If the engine starts, be ready to turn off the ignition promptly. Take these precautions because the car could possibly move without warning and possibly cause personal injury or property damage. On automatic transmission cars, try to start the engine in each gear. The starter should crank only in “Park” or “Neutral”. On manual transmission cars, place the shift lever in “Neutral”, push the clutch halfway and try to start. The starter should crank only when the clutch is fully depressed.
Steering Column Lock Operation – While parked, try to turn key to “Lock” in each gear range. The key should turn to “Lock” only when gear is in “Park” on automatic or “Reverse” on manual transmissions. On cars with key release lever, try to turn key to “Lock” without depressing the lever. The key should turn to “Lock” only with the key lever depressed. On all vehicles, the key should come out only in “Lock”.
Parking Brake an Transmission “Park” Mechanism Operation – CAUTION: Before checking the holding ability of the parking brake and automatic transmission “Park” mechanism, park on a fairly steep hill with enough room for movement in the downhill direction. To reduce the risk of personal injury or property damage, be prepared to apply the regular brakes promptly if the car begins to move. To check the parking brake, with the engine running and the transmission in “Neutral”, slowly remove foot pressure from the regular brake pedal (until the car is only held by the parking brake.) To check the automatic transmission “Park” mechanism holding ability, release all brakes after shifting the transmission to “Park”.
Underbody Flushing – At least every spring, flush from the underbody with plain water any corrosive materials used for ice and snow removal and dust control. Take care to thoroughly clean any areas where mud and other debris can collect. Sediment packed in closed areas of the vehicle should be loosened before being flushed.
Engine Cooling System Service – Inspect coolant and freeze protection. If dirty or rusty, drain, flush and refill with new coolant. Keep coolant at the proper mixture as specified in your Owner’s Manual. This provides proper freeze protection, corrosion inhibitor level and engine operating temperature. Inspect hoses and replace if cracked, swollen or deteriorated. Tighten hose clamps. Clean outside of radiator and air conditioning condenser. Wash radiator filler can and neck. To help ensure proper operation, a pressure test of both the cooling system and cap is also recommended.
1985 Corvette DIY Service Guide
Battery & Charging
Inspection & Replacement of Battery, Factory Battery Specifications, Replacement of Alternator/Generator. Click here to learn more.
Belts & Hoses
How to Replace Drive Belt(s), Inspection & Replacement of Upper/Lower Radiator Hoses
Inspection & Replacement of Brake Pads, Inspection & Replacement of Front/Rear Brake Rotors, How to Replace Brake Calipers, How to Bleed Brakes, Inspection & Replacement of Master Cylinder. Click here to learn more.
Inspection & Replacement of Radiator, How to Replace the Heater Core, Inspection & Replacement of Upper/Lower Radiator Hoses, How to Flush the Cooling System, How to Replace the Water Pump, How to Replace a Thermostat. Click here to learn more.
Location of, Inspection & Replacement of Oxygen Sensors (Upstream/Downstream), How to Replace the EGR Valve, How to Replace the Smog Pump
Location & Replacement of the Following Filters: Oil Filter, Fuel Filter, Transmission Filter, PCV Valve
Ignition & Tune Up
How to Replace the Ignition Coil, How to Replace the Ignition Switch, Inspection & Replacement of Sparkplug Wires, Inspection & Replacement of Cap & Rotor, How to Replace Sparkplugs, Engine Firing Order, Engine Timing
Relays & Sensors
Location & Replacement of: Mass Air Flow Sensor, Oil Pressure Sensor, Engine Temperature Sensor, Ambient Air Temperature Sensor, Fuel Pressure Sensor, Oxygen Sensors (Upstream/Downstream)
Suspension & Steering
Inspection & Replacement of Upper/Lower Ball Joints, How to Replace Control Arm Bushings, How to Replace the Power Steering Pump, Inspection & Replacement of Front Shocks/Struts, Inspection & Replacement of Rear Shocks/Struts, How to Replace Inner & Outer Tie Rod Ends
How to Replace the Starter Motor, How to Replace the Starter Solenoid, How to Replace the Drive Belt Tensioner, How to Replace the Idler Pulley, Location of, Inspection & Replacement of Engine (Motor) Mounts, How to Replace the Oil Pan Gasket, How to Replace the Oil Pump
Transmission & Clutches
How to Change the Transmission Filter (Automatic Transmission), How to Replace a Clutch (Manual Transmission)
1985 Corvette Dealers Sales Brochure
Download this 1985 Corvette Dealers Sales Brochure for a quick look at the features of the car.