Question 1

Rear Quarter Panel Corrosion

Accepted Answer

Bubbling paint on the rear quarter panels, progressing to perforation. Rust visible inside the boot behind the wheel arch trim. In severe cases, the inner wheelarch structure is completely gone and the outer skin is all that's holding the shape. Road spray from the rear tyres is flung up into the space between the inner and outer wheelarch panels. Mud, sand, and moisture sit in this cavity with no way to drain or dry. The steel rusts from the inside out, and by the time paint is bubbling on the outside, the inner structure has been rotting for years. Minor surface rust on the outer panel can be treated, sanded, and resprayed ($300-600 per side). Structural rust in the inner arch requires cutting out the affected metal and welding in new fabricated panels. This is skilled work and costs $1,500-3,000 per side. If both rear quarters need major work, the repair bill can exceed the car's value.

Question 2

Boot Floor and Spare Tyre Well Corrosion

Accepted Answer

Soft, rusted, or perforated metal in the boot floor. Water pooling in the spare tyre well. Damp smell from the boot. Rust staining on the boot carpet. Water enters the boot through deteriorated taillight gaskets, rear window seal, and boot lid seal. It pools in the lowest point (the spare tyre well) and sits there, rusting the metal from the top down. Cars that have been parked outdoors for extended periods are worst affected. Remove all trim and inspect the full boot floor. Surface rust: wire brush, treat with rust converter, and seal with chassis paint ($50-100 DIY). Perforated metal: cut out affected areas and weld in new steel. Boot floor replacement is a half-day job on a hoist. Cost: $500-1,500 depending on extent.

Question 3

Sill (Rocker Panel) Corrosion

Accepted Answer

Paint bubbling along the sills below the doors. Soft metal when tapped. In severe cases, the sill collapses when jacked, and the door gaps change as the body flexes. Sills are enclosed box sections that trap moisture. Water enters through blocked drain holes at the bottom of the sills and through the door shuts. Once rust starts inside the box section, it's invisible until it eats through the outer skin. Minor: cut out the rusted outer skin, treat the inner structure, and weld in a repair panel. Major: full sill replacement, requiring removal of the outer skin, repair or replacement of the inner sill, and refitting the outer panel. Cost: $1,500-2,500 per side.

Question 4

Floor Pan Corrosion

Accepted Answer

Soft or perforated floor pans. Visible rust when the carpet is lifted. In extreme cases, you can see the road through the floor. Road spray, trapped moisture, and minimal factory undersealing. Cars that have spent time on unsealed roads, or been parked on grass or dirt, accelerate floor pan corrosion. Surface rust: wire brush, rust converter, and underseal. Perforation: cut and weld new steel sections. Full floor replacement is a major job requiring a hoist or rotisserie. Cost: $500-1,500 for localised repair, $2,000-5,000 for extensive floor work.

Question 5

Oil Leaks

Accepted Answer

Oil weeping or dripping from multiple points on the engine. Oil residue on the rocker cover, sump, and rear of the engine. Oil spots under the car. Every gasket and seal in the K-series engine hardens and shrinks with age. The rocker cover gasket is the most common culprit, followed by the sump gasket, timing cover seal, and rear main seal. The rear main seal is a rope-type seal on early engines, which is notoriously difficult to seal perfectly. Rocker cover gasket: $15 for the gasket, 30 minutes to replace. Sump gasket: $20, requires dropping the sump (1-2 hours). Timing cover seal: $30, requires removing the radiator and timing cover. Rear main seal: $30 for the seal, but the gearbox must be removed to access it ($200-400 labour if you can't do it yourself).

Question 6

Timing Chain Wear

Accepted Answer

Rattling or slapping noise from the front of the engine, most noticeable at cold start and idle. The noise may diminish once the engine warms up and oil pressure stabilises the tensioner. The K-series uses a single-row timing chain with a mechanical or hydraulic tensioner. Over 200,000+ km, the chain stretches, the tensioner wears, and the chain guides deteriorate. Unlike a timing belt, the chain rarely breaks catastrophically, but excessive stretch retards the valve timing and reduces performance. Replace the timing chain, tensioner, and chain guides. The job requires removing the radiator, fan, and timing cover. Cost: $150-300 in parts, 4-6 hours labour. This is a straightforward job for a home mechanic with a workshop manual.

Question 7

Carburettor Problems

Accepted Answer

Rough idle, poor fuel economy, hesitation on acceleration, black smoke from the exhaust, engine stalling. Difficulty starting when cold or when hot (vapour lock). The KE70's Aisan carburettor is a reliable unit, but after 40+ years the float valve wears (causing flooding or lean conditions), the accelerator pump diaphragm perishes, jets become partially blocked with varnish from old fuel, and vacuum hoses crack and leak. A full carburettor rebuild kit costs $40-80 and includes a new float valve, needle and seat, accelerator pump, gaskets, and O-rings. Rebuilding the carburettor is a 2-3 hour job at the kitchen table. Alternatively, a complete replacement carburettor (new aftermarket or reconditioned original) costs $150-300. Many owners replace the factory carburettor with a Weber 32/36 DGEV for improved throttle response and tunability ($300-500 installed).

Question 8

Overheating

Accepted Answer

Temperature gauge climbing into the red, coolant loss, steam from under the bonnet. In severe cases, head gasket failure. The original radiator is a brass/copper unit that corrodes internally over decades, reducing cooling capacity. The thermostat sticks closed (or partially closed), the water pump impeller corrodes, and coolant hoses become soft and swell under pressure, reducing flow. Blocked radiator fins (from insects, mud, and road debris) reduce airflow. Replace the thermostat ($15), water pump ($40-80), all coolant hoses ($50-100 for a full set), and radiator cap ($10). If the radiator is original and more than 30 years old, replace it with a new aftermarket unit ($100-200 for brass, $150-300 for aluminium). Flush the cooling system and refill with quality coolant.

Question 9

Synchro Wear (2nd and 3rd Gear)

Accepted Answer

Crunching or grinding when shifting into second or third gear, especially on quick downshifts. The synchro ring can't match the input and output shaft speeds, causing the gear teeth to clash. The T50 is a compact, lightweight gearbox originally designed for the K-series engine's modest torque. Second gear synchro wear is accelerated by aggressive driving, particularly rev-matched downshifts and drift-car abuse. On engine-swapped cars with significantly more torque, the T50 synchros wear even faster. Gearbox rebuild with new synchro rings, bearings, and seals. Cost: $800-1,500. For engine-swapped cars making more than 100 kW, consider upgrading to a W50, W55, or W58 gearbox from the Celica or Supra. These are stronger, shift better, and handle more torque. W-series swap: $500-1,000 for the gearbox plus $200-400 for bellhousing adaptation.

Question 10

Gearbox Oil Leaks

Accepted Answer

Oil leaking from the input shaft seal, output shaft seal, or gearbox-to-bellhousing joint. Oil dripping onto the exhaust or ground. Seals harden and shrink with age. The input shaft seal is the most common leak point, followed by the rear output shaft seal. Input shaft seal replacement requires removing the gearbox ($200-400 labour). Output shaft seal can sometimes be replaced in situ. Seals cost $10-20 each. If you're already pulling the gearbox for a clutch or rebuild, replace all seals while it's out.

Question 11

Differential Noise

Accepted Answer

Whining from the rear axle that changes pitch with speed. Clunking on acceleration or deceleration, particularly when transitioning from drive to coast. The ring and pinion wear over time. Incorrect backlash (from a previous rebuild or service) accelerates wear. Cars used for drifting subject the diff to enormous side loads that increase wear rates. Worn pinion bearings and carrier bearings also contribute to noise. Diagnose the noise type first. Continuous whine that changes with speed is gear wear or incorrect mesh. Clunking on drive/coast transition is backlash. Rumbling is bearing wear. Bearing replacement: $200-500. Full diff rebuild with new ring and pinion: $800-1,500. Replacement diff centres from wreckers: $100-300.

Question 12

Rear Axle Bearing Noise

Accepted Answer

Humming or grinding noise from one or both rear wheels that increases with speed. Noise doesn't change with braking (distinguishing it from brake noise). The rear axle bearings are sealed units that wear over time. Contamination from damaged seals or loss of lubricant accelerates failure. Replace the rear axle bearings and seals. This requires pulling the axle shafts. Cost: $50-100 per side for bearings and seals, 2-3 hours labour.

Question 13

Heater Tap Failure

Accepted Answer

Coolant leak from the heater tap (located on the firewall). Wet carpet on the passenger side. Sweet smell of coolant inside the cabin. Loss of heating function. The heater tap is a vacuum-operated valve that controls coolant flow to the heater core. The vacuum diaphragm perishes, or the tap body corrodes and leaks. After 40+ years, these are living on borrowed time. Replace the heater tap. Universal heater taps are available for $20-40 and are a straightforward replacement. Some owners bypass the heater tap entirely with a manual inline valve ($10).

Question 14

Ignition System Deterioration

Accepted Answer

Hard starting, misfires, rough running, loss of power, poor fuel economy. Engine cutting out intermittently. The KE70 uses a points-and-condenser ignition system (early cars) or an electronic ignition system (later cars). Points pit and wear, condenser capacitors fail, the distributor cap cracks, rotor buttons burn, and high-tension leads deteriorate with age and heat. Full ignition service: new points and condenser (if applicable, $15-25), distributor cap and rotor ($20-40), spark plugs ($15-30), and high-tension leads ($30-60). For points-equipped cars, upgrading to an electronic ignition module (Pertronix or similar) eliminates points maintenance entirely. Cost: $80-150 for the module.

Question 15

Worn Bushings

Accepted Answer

Vague, imprecise handling. Clunking and knocking over bumps. Uneven tyre wear. The car wanders on the highway and feels disconnected in corners. Every rubber bushing in the car — control arm bushings, trailing arm bushings, Panhard rod bushings, sway bar bushings, steering rack mounts — has perished from 40+ years of age, heat, and UV exposure. Replace all suspension bushings. A full polyurethane bushing kit is the best long-term solution: it firms up the chassis, lasts longer than rubber, and is widely available for the KE70/AE86 platform. Cost: $150-350 for a full poly set, plus a day of labour.

Question 16

Steering Rack Wear

Accepted Answer

Excessive play in the steering wheel before the front wheels respond. Vague centre feel. Clunking from the steering rack on rough surfaces. The steering rack bushings and internal components wear with age and mileage. Damaged rubber boots allow contamination of the rack internals. Adjust the rack preload (free). Replace rack boots ($20-40). If the rack is worn internally, replacement is the best option — reconditioned racks are available for $150-300 exchange. Second-hand racks from wreckers: $50-100.

KE70 Corolla

KE70 Corolla known problems