280ZX Buyers Guide - What to look for when buying a S130.

A compression test is a quick and inexpensive way to assess engine health. It can be performed by you or an independent mechanic.

Procedure

1. Remove all spark plugs.
2. Screw a pressure gauge into one cylinder.
3. Crank the engine the same number of rotations for each cylinder.
4. Record the “dry” compression reading for all cylinders.
5. Add a small amount of oil to each cylinder and repeat for the “wet” test.

Interpreting Results

• Under 130 psi (dry): Engine is showing wear.
• More than 15 psi difference between highest and lowest cylinder — one is significantly weaker.
• Wet test rises 20+ psi: Bad piston rings.
• Low dry pressure with little wet test change: Valve issues.
• Even but low (≈115 psi): Engine is worn but balanced; will run but lack power.

The Nissan straight-six is famously durable. Even with slightly low readings, careful maintenance can prolong engine life before a rebuild is needed.

Gauges & Accessories

• Check all gauges and accessories for proper function.
• If an aftermarket stereo is installed, inspect the wiring — messy wiring can mean future headaches.
• Allow for 2+ hours labor or deduct $100–$150 from the price for wiring cleanup.

Dash Condition

• Cracks on top of the dash are common in older Z cars due to the factory vinyl material.
• Options:
  • Dash cap or carpet cover: ~$80
  • Used replacement dash: ~$200
  • New OEM dash: $700+
• Most owners choose to live with cracks or use a cap.

Rear Hatch Carpet

• Sun damage is common; not a major concern.
• Replacement can be made by an upholstery shop for under $100.

Oil pressure is a key indicator of the health of the Z’s straight-six engine.

• Cold engine at road speed (3000 RPM): should show at least 60 psi.
• Warm engine at idle: can drop to 10–15 psi — this is normal for these engines.
• If cold oil pressure is under 50 psi, the engine may be significantly worn and could require a rebuild.

Note: The factory gauge is a useful guide, but confirming with a mechanical test gauge is more accurate.

The front suspension and steering components on these Z cars are generally robust, but it’s still worth a careful check.

• Have a shop inspect the front brakes for wear, rotor condition, and caliper operation.
• Check for bent or damaged wheels — factory wheels can be expensive to replace unless you find them at a salvage yard.
• Listen for any unusual noises during steering or braking, which could indicate worn suspension bushings or ball joints.

If the 280ZX you’re looking at is a turbo model, take extra care with your inspection. Turbos require more maintenance than many owners realize.

• During a test drive, at 3000 RPM or higher, flooring the throttle should make the boost gauge reach the red zone within one second.
• If the gauge fails to hit at least the lower end of the red, the turbo is likely worn and needs replacement.
• Rebuilt turbos typically cost around $500, plus 6–8 hours of labor to install.
• If replacing a turbo, always replace the oil feed line — it adds about an hour of labor but prevents clogging and premature turbo failure.
• Use only synthetic oil in a turbocharged engine for the best protection and longevity.

For a true sports car experience, a manual transmission is strongly recommended. The 280ZX is far more engaging and responsive with a 4-speed or 5-speed stick compared to an automatic, which reduces performance.

• The transmission should shift smoothly without grinding between gears.
• It should not pop out of gear during deceleration.
• The drivetrain should feel tight — noticeable “slack” can indicate issues with the rear motor mount or rear end.
• Used transmissions are readily available, but replacement is roughly a full day’s labor.

If possible, always speak with the previous owner before purchasing. Understanding why the car is being sold can reveal valuable insights about its condition and history.

• Ask about maintenance habits and service history.
• Inquire about any accidents, repairs, or modifications.
• Gauge whether the car was a practical daily driver, a weekend toy, or a neglected project.
• Unusual reasons for selling can sometimes be telling — or entertaining — but always note them.

Synthetic lubricants offer superior protection, performance, and longevity for Z-cars and other performance vehicles. They reduce wear, improve efficiency, and maintain stability under extreme temperatures.

• Recommended engine oils include Mobil 1, Amsoil, and Red Line.
• Use synthetics in the engine, transmission, and rear differential.
• Benefits include smoother shifting and extended component life.
• A history of synthetic use often indicates a meticulous and careful owner.