What To Look For When Buying A 240sx

So, you're thinking about picking up a 240sx? Excellent choice! These cars are fantastic platforms for just about anything, from spirited daily driving to full-blown track builds. But before you hand over your hard-earned cash, you need to know what to look for. These cars are getting older, and they've likely seen their fair share of abuse. This guide will walk you through the critical areas to inspect to ensure you're getting a solid foundation, not a money pit.

Chassis & Body

This is arguably the most crucial aspect. Rust is the 240sx's arch-nemesis. Neglecting this area can lead to significant headaches down the road. Here's a breakdown of where to focus your attention:

Rust Inspection Points:

Frame Rails: These are the longitudinal beams running beneath the car. Use a flashlight and get down on your knees. Look for flaking, bubbling paint, or even holes. Poke suspected areas with a screwdriver – if it goes through easily, walk away. Frame rail damage is a structural issue and costly to repair correctly.
Rocker Panels: Located beneath the doors, these are another common rust spot. Pay close attention to the area where the rocker panels meet the rear wheel wells.
Wheel Wells: Front and rear, check for rust, especially around the edges and seams. The rear wheel wells are notorious for collecting dirt and moisture, leading to rust.
Floor Pans: Lift the carpets (if possible) and inspect the floor pans, particularly in the front footwells and under the rear seats. Leaky windshield seals and t-tops (if applicable) can contribute to rust here.
Hatch/Trunk Area: Check for rust around the taillights, the spare tire well, and the edges of the hatch opening. Water often collects in this area.
Strut Towers: Inspect the strut towers (under the hood and in the trunk) for rust and cracking. These are critical for suspension integrity, and rust here is a major red flag.

Body Damage: Look for signs of previous accidents. Mismatched paint, uneven panel gaps, and poorly aligned body panels can indicate that the car has been in a collision. A Carfax or similar vehicle history report can also provide valuable information about the car's past.

Pro Tip: Bring a small magnet with you. If the magnet doesn't stick firmly to a panel, it could indicate the presence of body filler (Bondo) used to cover up damage.

Engine & Drivetrain

The 240sx was originally equipped with either an KA24E (single cam) or KA24DE (dual cam) engine. Many have been swapped for other engines, most commonly the SR20DET (turbocharged) or even V8s. The condition of the engine and drivetrain is paramount to the overall value and reliability of the car.

KA24E/DE Inspection (Stock Engines):

Compression Test: This is the single most important test you can perform. A compression test measures the pressure inside each cylinder, indicating the health of the piston rings and valves. Low or uneven compression is a sign of internal engine damage.
Oil Condition: Check the oil dipstick. The oil should be clean and free of sludge or metal particles. Milky or frothy oil can indicate a coolant leak into the engine.
Coolant Condition: Inspect the coolant in the radiator and overflow tank. It should be clean and green (or the appropriate color for the type of coolant used). Brown or rusty coolant indicates corrosion.
Leaks: Look for oil leaks around the valve cover, oil pan, and front and rear main seals. Also, check for coolant leaks around the water pump, hoses, and radiator.
Smoke: Start the engine and observe the exhaust. Blue smoke indicates burning oil, while white smoke indicates burning coolant. Black smoke suggests a rich fuel mixture. A small puff of smoke on startup can be normal, especially on older engines, but excessive smoke is a cause for concern.
Idle: The engine should idle smoothly and consistently. A rough or erratic idle can indicate vacuum leaks, a faulty idle air control (IAC) valve, or other engine problems.
Timing Chain Noise (KA24DE): Listen for rattling or chain noise, especially at startup. The KA24DE is known for timing chain issues.

SR20DET Inspection (Common Swap):

If the car has an SR20DET swap, the inspection process is similar to the KA engines, but with a few key differences:

Turbocharger: Check the turbocharger for shaft play. Excessive shaft play indicates worn bearings and can lead to turbo failure. Also, look for oil leaks around the turbocharger.
Boost Leaks: Listen for hissing sounds during acceleration, which can indicate boost leaks in the intercooler piping or other boost-related components.
Aftermarket Modifications: Pay attention to the quality of the SR20DET swap. Was it done professionally, or was it a backyard job? Look for clean wiring, proper plumbing, and quality aftermarket parts. A poorly executed swap can be a nightmare to deal with.

Transmission & Differential:

Manual Transmission: Check for smooth shifting through all gears. Listen for grinding noises, especially when shifting into second or third gear. The 240sx manual transmission (typically a 5-speed) can be prone to wear over time. Ensure the clutch engages smoothly and doesn't slip under load.
Automatic Transmission: Check for smooth shifting and proper engagement of all gears. Slipping or harsh shifting indicates transmission problems. The fluid should be bright red and free of debris.
Differential: Listen for unusual noises from the rear end, such as whining or clunking. These noises can indicate a worn differential. Check for leaks around the differential seals.

Suspension & Brakes

The 240sx has a fully independent suspension, which provides excellent handling. However, worn suspension components can significantly degrade the car's performance and safety.

Suspension Inspection:

Shocks/Struts: Inspect the shocks and struts for leaks. Leaking shocks are a sign that they are worn out and need to be replaced. Bounce the car at each corner; it should rebound smoothly and settle quickly. Excessive bouncing indicates worn shocks.
Control Arms & Bushings: Check the control arms and bushings for wear and tear. Cracked or worn bushings can cause sloppy handling and uneven tire wear. Look for play in the ball joints.
Tie Rods: Inspect the tie rods for play. Excessive play can cause wandering and poor steering response.
Sway Bars: Check the sway bar bushings and end links for wear. Worn sway bar components can reduce the effectiveness of the sway bars.

Brake Inspection:

Brake Pads & Rotors: Check the brake pads and rotors for wear. The pads should have sufficient thickness, and the rotors should be smooth and free of deep grooves or cracks.
Brake Lines: Inspect the brake lines for leaks or corrosion. Leaking brake lines are a serious safety hazard.
Brake Calipers: Check the brake calipers for leaks and proper function. The calipers should move freely and not be seized.
Brake Master Cylinder: Inspect the brake master cylinder for leaks. A leaking master cylinder can cause a soft or spongy brake pedal.

Interior & Electronics

While not as critical as the mechanical aspects, the interior and electronics can provide clues about how well the car has been maintained. Also, repairing or replacing interior components can quickly add up.

Interior Inspection:

Seats: Check the seats for rips, tears, and excessive wear.
Dashboard: Inspect the dashboard for cracks or fading.
Carpets: Check the carpets for stains, tears, and water damage.
Headliner: Inspect the headliner for sagging or staining.
All Electronics: Test all the electrical components, including the lights, wipers, windows, locks, and radio. Ensure all gauges are functioning correctly.

Electrical Inspection:

Wiring Harness: Look for cut, spliced, or damaged wiring. Poorly executed wiring repairs can cause electrical problems and even fires.
ECU (Engine Control Unit): If the car has been modified, check to see if the ECU has been properly tuned. An improperly tuned ECU can cause engine damage.

Final Thoughts: Buying a 240sx requires patience and diligence. Don't be afraid to walk away from a car that doesn't meet your standards. A thorough inspection and a willingness to negotiate will help you find a solid 240sx that you can enjoy for years to come. Remember to factor in potential repair costs when making your offer. Good luck, and happy motoring!