Question 1

Timing Chain Stretch and Guide Wear (SR20DET/SR20DE)

Accepted Answer

Rattling or clattering from the front of the engine, most pronounced on cold start. The noise may diminish when warm but persist at idle. In severe cases, the engine loses power, runs rough, or misfires. The SR20 uses a timing chain (not a belt) driven from the crankshaft to the camshaft sprockets. Over time, particularly above 150,000 km, the chain stretches and the plastic chain guides wear down. The hydraulic chain tensioner compensates for some stretch, but eventually the chain becomes excessively loose. A severely stretched chain can jump a tooth on the camshaft sprocket, causing the valve timing to shift. In extreme cases, this leads to valve-to-piston contact and significant engine damage. Replace the timing chain, chain guides, and chain tensioner as a set. The job requires removing the front timing cover, which means removing the radiator, fan, and various accessories. It is a full day's work for a competent mechanic. Parts: $200-400 for a complete kit (chain, guides, tensioner, gaskets). Labour: $400-600 at a workshop. This is a DIY-friendly job for experienced home mechanics.

Question 2

Turbo Oil Seal Failure (SR20DET)

Accepted Answer

Blue smoke from the exhaust, particularly on boost or on deceleration (overrun). Oil consumption increases. Oil residue visible in the intercooler piping. The factory T25 (S13) and T28 (S14/S15) turbochargers develop worn oil seals with age and mileage. The turbo shaft rotates at up to 150,000 rpm, and the seals that prevent oil from leaking into the compressor and turbine housings deteriorate over time. High exhaust temperatures, inadequate cool-down periods (shutting the engine off immediately after hard driving), and infrequent oil changes accelerate seal wear. Rebuild or replace the turbocharger. A rebuild (new seals, bearings, and balancing) costs $500-1,000. A new or aftermarket replacement turbo costs $800-2,500 depending on specification. Many owners use the turbo rebuild as an opportunity to upgrade, a Garrett GT2871R or similar is a popular swap that provides more power potential while fitting in the factory location.

Question 3

Boost Leaks

Accepted Answer

Sluggish boost response, reduced power, the car feels slow despite the turbo appearing to spool. The factory intercooler piping uses rubber couplers and worm-drive clamps that deteriorate with age and heat. Vacuum lines crack and split. The blow-off valve diaphragm wears. The intercooler end tanks can crack (particularly on aftermarket intercoolers with aluminium tanks and poor welds). Any leak in the pressurised intake system reduces the boost reaching the engine. Perform a boost leak test: cap off the intake and the throttle body, pressurise the system to 15-20 psi with compressed air, and listen/spray for leaks. Replace all rubber couplers ($30-60 for a set of silicone replacements), upgrade to T-bolt clamps ($20-40 for a set), and inspect the intercooler for cracks. Replace the blow-off valve if the diaphragm is torn. Cost: $100-300 for a complete refresh.

Question 4

Idle Air Control Valve (IACV) Failure

Accepted Answer

Erratic idle speed, the RPM hunts up and down between 500 and 1,500 rpm. The engine may stall at traffic lights or when coming to a stop. The IACV is a stepper motor that controls idle speed by regulating air bypass around the throttle plate. Carbon deposits from PCV blowby clog the valve, and the stepper motor wears with age. Vacuum leaks can also cause hunting idle, so the IACV should be checked after eliminating boost/vacuum leaks. Remove the IACV and clean it with carburettor cleaner or throttle body cleaner. The stepper motor pintle should move freely. While the IACV is off, clean the idle air passage in the throttle body. If cleaning does not resolve the issue, replace the IACV: $100-200 for an aftermarket unit, $300+ for genuine Nissan. Cost: usually free if cleaning works.

Question 5

Coolant Temperature Sensor Failure

Accepted Answer

The temperature gauge reads incorrectly (stuck on cold, reads erratically, or pegs to hot without the engine actually overheating). The engine may run rich on cold start or overheat without the fans activating. The coolant temperature sensor, which sends data to both the dashboard gauge and the ECU, corrodes and gives incorrect readings. There are two sensors on the SR20: one for the gauge and one for the ECU. Both can fail independently. Replace the coolant temperature sensor(s). The ECU sensor is the more critical of the two, incorrect readings cause the ECU to miscalculate fuel delivery and fan activation. Cost: $30-60 per sensor. The job takes 15 minutes.

Question 6

2nd Gear Synchro Wear (5-Speed Manual)

Accepted Answer

Grinding or crunching when shifting into 2nd gear, particularly on quick downshifts from 3rd. May also grind on fast upshifts from 1st. The problem worsens with use. Second gear takes the most abuse in normal driving, every stop-start cycle involves a 1st-to-2nd shift. In a Silvia that has been drifted, the 2nd gear synchro bears even more punishment: clutch kicks, quick shifts, and abrupt downshifts all accelerate synchro wear. The 5-speed gearbox in the S13 and S14 is adequate but not over-built, and the synchro rings are a known wear item. Gearbox rebuild with new synchro rings, bearings, and seals. Cost: $1,000-2,000 for parts and labour. A used gearbox from a wrecker is an alternative ($500-1,000) but may have the same issues. The S15 Spec-R's 6-speed gearbox is a desirable swap for S13/S14 owners but requires adaptation. Double-clutching on downshifts extends synchro life considerably.

Question 7

Clutch Wear and Judder

Accepted Answer

The clutch slips under hard acceleration (engine revs rise but speed does not increase). Clutch judder (vibration when engaging from a standstill). The bite point moves progressively higher toward the top of the pedal travel. The factory clutch is designed for the SR20DET's stock power output. It wears naturally with use, and hard driving (particularly drift-style clutch kicks) accelerates wear dramatically. Clutch judder often indicates a warped or contaminated friction disc. Replace the clutch disc, pressure plate, and throw-out bearing as a set. A standard replacement costs $500-1,000 fitted. For modified cars, an aftermarket performance clutch (Exedy, Xtreme, ORC) is required: $800-2,500 depending on specification. Dual-mass flywheel to solid flywheel conversion is a common and recommended modification.

Question 8

Differential Wear

Accepted Answer

Clunking from the rear under acceleration and deceleration. Whining at highway speeds. On LSD-equipped cars, the LSD may lose its locking capability (the car behaves like it has an open diff, only one wheel spins under power). The differential bearings wear with age, and the limited-slip plates (in LSD-equipped cars) wear with use. Infrequent diff oil changes accelerate wear. Drift use is particularly hard on differentials. For bearing noise, the diff needs a rebuild: $500-1,000. For a worn LSD, the clutch pack can be replaced: $300-600 in parts. Many owners upgrade to an aftermarket 2-way LSD (Cusco, Kaaz, OS Giken) for more aggressive and consistent locking: $800-2,000. Diff oil should be changed every 20,000 km.

Question 9

Front Lower Control Arm Bushing Wear

Accepted Answer

Clunking over bumps, vague steering, uneven tyre wear on the inner edges of the front tyres. The rubber bushings in the front lower control arms perish with age. The Silvia's suspension uses a multi-link front design with multiple bushings per arm, all of which deteriorate over 25-35 years. Replace the control arm bushings. Polyurethane bushings are available from Whiteline, SuperPro, and Nismo: $200-400 for a front set. Complete control arms with pre-pressed bushings are also available. The job takes 3-4 hours per side.

Question 10

Tension Rod Bushing Failure (S13)

Accepted Answer

A feeling that the front wheels are "walking" over bumps. Clunking from the front suspension. The car pulls to one side under braking. The S13 uses tension rods (also called compression rods or radius arms) to locate the front lower control arms longitudinally. The rubber bushings at the chassis end of these rods are a known weak point, they soften and tear with age, allowing the control arm to move fore and aft. Replace the tension rod bushings. Polyurethane bushings are far more durable than the original rubber: $80-150 for a pair. For drift and track use, solid tension rod bushings are available but transmit more NVH (noise, vibration, harshness).

Question 11

Rear Subframe Bushing Wear

Accepted Answer

Clunking from the rear over bumps. Vague rear-end feel. The rear end feels "loose" or unstable, particularly during transitions (changing direction). The rear subframe is mounted to the body with rubber bushings that wear with age. The Silvia's relatively light unibody is stressed at these mounting points, and the bushings deteriorate faster if the car has been driven hard. Replace the rear subframe bushings. Polyurethane or solid bushings are available: $100-250 for a set. The job requires supporting the rear subframe, lowering it slightly, and pressing in the new bushings. Labour: 2-4 hours.

Question 12

Coil Pack and Ignition Failure

Accepted Answer

Misfire on one or more cylinders, rough idle, loss of power. The SR20DET uses a coil pack (S13/S14) or coil-on-plug (S15) ignition system. The coil packs deteriorate with age and heat, and the spark plug leads (on S13/S14) develop insulation breakdown. Modified cars running higher boost are more susceptible, as the increased cylinder pressure makes it harder for the spark to jump the plug gap. Replace the coil pack and leads (S13/S14) or coil-on-plug units (S15). Cost: $150-400 for a set. Aftermarket high-energy coils are available for modified cars. Replace spark plugs at the same time, use one heat range colder than stock for modified cars.

Question 13

Wiring Harness Deterioration

Accepted Answer

Intermittent electrical faults, blown fuses, sensors giving incorrect readings, check engine light. On an S13 that is now 32-37 years old, the original wiring insulation becomes brittle, particularly in the engine bay where heat exposure is constant. Add decades of aftermarket modifications, boost controllers, gauges, lighting, stereo equipment, and the wiring harness becomes a compromised mess of splices, scotch-locks, and exposed conductors. For specific faults, trace and repair the affected circuit. For a comprehensive solution, a complete reproduction engine harness is available from Wiring Specialties ($400-800) and is highly recommended for any S13 or S14 undergoing restoration or significant modification. The S15's wiring is generally in better condition due to its newer age.

Question 14

Rear Quarter Panel Rust

Accepted Answer

Bubbling paint, perforation, and structural corrosion behind the rear wheels. Road spray is thrown against the inner guard, which is a double-skinned area. Moisture gets trapped between the inner and outer panels and corrosion works from the inside out. This affects all three generations but is worst on the S13. Cut out the affected metal, fabricate or source repair panels, and weld in. This is panel-and-paint work: $1,500-3,000 per side for a professional repair. Reproduction quarter panel sections are available for the S13 from specialist suppliers.

Question 15

Sill Corrosion

Accepted Answer

Rust visible on the sills (rocker panels), starting as bubbles and progressing to holes. The box-section sills trap moisture from road spray. The drain holes become blocked with debris, and the trapped water corrodes the metal from inside. Minor corrosion can be treated with rust converter and sealed. Perforated sills require cutting out the damaged section and welding in repair panels. This is structural work and must be done properly. Cost: $1,000-2,500 per side.

Question 16

Pop-Up Headlight Motor Failure (S13 180SX)

Accepted Answer

One or both pop-up headlights fail to open, open partially, or open at different speeds. The pop-up headlight mechanism uses electric motors and a linkage system. The motors wear with age, and the pivot points seize from corrosion. Water ingress into the motor housing accelerates failure. Lubricate the pivot points and linkage with white lithium grease. If the motor has failed, replacement motors are available from wreckers ($100-200 each) or aftermarket suppliers. Some owners convert to fixed headlight conversions for simplicity.

Question 17

Overheating Under Hard Use

Accepted Answer

Coolant temperature climbs above normal during spirited driving, traffic, or hot days. The factory cooling system is adequate for normal driving but marginal for sustained hard use, particularly on modified cars producing more heat. Common contributing factors: a partially blocked radiator (30+ years of scale buildup), a thermostat that is slow to open, collapsed lower radiator hose (the hose needs an internal spring to prevent collapse under pump suction), and a thermo fan that is not pulling sufficient air. Flush and inspect the radiator, if it is heavily scaled, replace it with an aftermarket aluminium unit ($200-400). Replace the thermostat ($20-30), all coolant hoses ($100-150 for a complete set), and check thermo fan operation. For modified cars, a larger radiator and an upgraded fan setup are recommended.

Silvia (S13 / S14 / S15)

Silvia (S13 / S14 / S15) known problems