Porsche 924

Porsche 924

1976–1988

The underrated transaxle Porsche, and the cheapest way into a proper Porsche chassis.

  • 2.0L I4 (Audi)
  • 2.5L I4 (924S)
  • 2.0L Turbo I4

Common Issues

What goes wrong on the 924, how to spot it, and what it costs to fix.

Timing Belt Failure

Advanced

Symptoms: Engine won't start, loud slapping noise, bent valves after failure, visible belt cracking or fraying

Every 924 drives its camshaft with a rubber belt, and the engines are interference designs, so a snapped belt means bent valves. Replace it every 30,000 to 40,000 miles or four years. The 924S uses the 944's 2.5L, which adds balance shaft belts that must be done at the same time. The 2.0L cars, including the Turbo, don't have balance shafts.

Estimated Repair Costs

DIY $150–300
Shop $500–900

Interference engine. Every 30,000–40,000 miles.

Common Fixes

  • Replace timing belt every 30,000-40,000 miles or 4 years
  • Replace water pump at the same time (driven by timing belt)
  • Replace timing belt tensioner and idler rollers
  • On 924S/Turbo: replace balance shaft belt simultaneously
  • Inspect and replace front crankshaft and camshaft seals if leaking
  • Use oem or high-quality belts (Gates, Continental)

Common Parts

Part Part Number Typical price
Timing Belt 951.105.151.90 $40–70
Tensioner 951.105.511.00 $50–100
Water Pump 951.106.011.00 $60–100

CIS Fuel Injection Problems

Moderate

Symptoms: Hard starting (especially when cold or hot), rough idle, hesitation under acceleration, poor fuel economy, flooding, black smoke

The 2.0L cars use Bosch K-Jetronic (CIS) mechanical fuel injection. It's clever, durable, and completely dependent on correct fuel pressures, which drift as the warm-up regulator, fuel accumulator, and injectors age. Hard hot starts and rough warm-up are the classic symptoms. Test the pressures before replacing parts. The 924S uses the 944's electronic DME system instead.

Estimated Repair Costs

DIY $100–400
Shop $300–800

Test fuel pressures first. The warm-up regulator and accumulator are the usual culprits.

Common Fixes

  • Test and set system pressures (control pressure, system pressure, residual pressure)
  • Replace warm-up regulator (wur) if control pressure is incorrect
  • Clean or replace fuel injectors (rebuild kits available)
  • Replace fuel accumulator if car is hard to hot-start
  • Check fuel pump delivery volume and pressure
  • Inspect air flow sensor plate for smooth movement
  • Replace all rubber fuel lines (ethanol degrades old rubber)

Common Parts

Part Part Number Typical price
Warm-Up Regulator Bosch $200–400
Fuel Accumulator Bosch $100–200
Fuel Injector (each) Bosch $40–80

Clutch Cable and Clutch System Wear

Advanced

Symptoms: Heavy clutch pedal, clutch slipping, difficulty shifting, clutch pedal sticks down, grinding when shifting

The clutch is cable-operated, and the cable runs a long way through the central tunnel to the transaxle at the back. It stretches with age, and the guide tube wears, so the pedal gets heavy and the engagement point moves. Adjust it first; replace it if adjustment doesn't bring it back.

Estimated Repair Costs

DIY $50–100
Shop $150–300

Adjust first, then replace.

Common Fixes

  • Adjust clutch cable to restore proper free play
  • Replace clutch cable if stretched beyond adjustment or frayed
  • Lubricate cable guide tube if pedal feel is poor
  • When replacing clutch, always replace throwout bearing, pilot bearing, and clutch fork
  • Consider upgraded clutch kits for spirited driving

Common Parts

Part Part Number Typical price
Clutch Cable 944.237.211.06 $40–80

Sources: Rennlist, 924Board

Rust and Corrosion

Advanced

Symptoms: Bubbling paint, visible rust holes, soft floors, leaking trunk or cabin, rusty battery box

Check the battery box first, because acid eats it. Then the front fenders behind the headlights and along the bottom edges, the door bottoms, the rockers, and the area around the rear hatch seal. Later cars are galvanized and hold up better, but 40 years finds every weak spot.

Estimated Repair Costs

DIY $200–1,000
Shop $1,000–5,000+

Battery box, fenders, and floors are the common spots.

Common Fixes

  • Inspect battery box regularly and neutralize acid
  • Check and clear all drain holes (doors, rocker panels, floor plugs)
  • Replace front fenders if rust is extensive (reproduction available)
  • Weld in repair panels for floor pan rust
  • Apply rust prevention coating (por-15, Eastwood)
  • Treat cavity areas with rust prevention spray

Common Parts

Part Part Number Typical price
Fender (Repro) Varies $150–300
Battery Box Repair Varies $80–150

Sources: 924Board, Rennlist

Electrical System Issues

Moderate

Symptoms: Intermittent no-start, dead gauges, flickering lights, non-functional windows/mirrors, fuel pump runs constantly

Forty-plus years of heat and vibration take a toll. Corroded grounds, tired wiring insulation, and a failing fuel pump relay cause most problems, and the combination relay on the fuse panel runs several functions and fails often. On a 924S, add the DME relay to the list.

Estimated Repair Costs

DIY $50–200
Shop $150–400

Relays and grounds. Carry a spare fuel pump relay.

Common Fixes

  • Replace DME/fuel pump relay with new oem unit
  • Clean and tighten all ground connections
  • Inspect and repair wiring under the hood (heat damage common)
  • Replace combination relay if multiple electrical functions affected
  • Repair or replace instrument cluster circuit board
  • Replace ignition switch if experiencing intermittent starting issues

Common Parts

Part Part Number Typical price
DME/Fuel Pump Relay 928.615.301.20 $30–60
Combination Relay Varies $40–80

Cooling System Failures

Advanced

Symptoms: Overheating, coolant leaks, heater not working, temperature gauge fluctuation, steam from engine bay

The water pump is driven by the timing belt, so replace it with every belt job. Radiator plastic end tanks go brittle with age. The Turbo runs hotter and is less forgiving of a tired cooling system.

Estimated Repair Costs

DIY $150–300
Shop $400–700

Refresh the whole system on a car this age.

Common Fixes

  • Replace water pump with every timing belt service
  • Replace thermostat (use oem temperature rating)
  • Upgrade to aluminum or modern radiator if plastic tanks cracking
  • Replace all coolant hoses (including heater hoses)
  • Flush cooling system and use proper coolant
  • On turbo models: inspect turbo coolant lines and oil cooler

Common Parts

Part Part Number Typical price
Water Pump 951.106.011.00 $60–100
Thermostat Varies $20–40
Radiator Varies $150–300

Transaxle and Differential Issues

Advanced

Symptoms: Grinding when shifting, popping out of gear, whining noise from rear, difficulty engaging reverse, oil leaks

The gearbox and differential sit together at the back in a transaxle. Second-gear synchros wear, the shift linkage gets sloppy over its long run, and a tired transaxle mount makes shifting vague. Use the correct GL-4 gear oil, not GL-5, to protect the synchros.

Estimated Repair Costs

DIY $100–300
Shop $400–1,500

Use GL-4 gear oil.

Common Fixes

  • Change transaxle fluid regularly with correct GL-4 gear oil
  • Replace transaxle mount (donut) if shift quality is poor
  • Rebuild or replace shift linkage bushings
  • For synchro wear: rebuild transaxle or find quality replacement
  • Replace output shaft seals if leaking

Common Parts

Part Part Number Typical price
Trans Mount (Donut) 944.333.235.00 $30–60
Shift Bushing Kit Varies $40–80
GL-4 Gear Oil Varies $30–50

Sources: 924Board, Rennlist

Suspension and Steering Wear

Moderate

Symptoms: Clunking over bumps, vague steering, uneven tire wear, wandering at highway speed, squeaking from front end

Nearly every 924 needs suspension work by now: strut mounts, control arm bushings, tie rod ends, and ball joints. The steering rack can also develop play or leak.

Estimated Repair Costs

DIY $200–400
Shop $500–900

Bushings and strut mounts are due on every car this age.

Common Fixes

  • Replace strut mounts (bearing and rubber mount)
  • Install new shocks/struts (Bilstein, Koni, KW available)
  • Replace all control arm bushings
  • Replace tie rod ends and check steering rack for play
  • Rebuild or replace steering rack if leaking or worn
  • Perform full alignment after suspension work

Common Parts

Part Part Number Typical price
Strut Mount Varies $40–80
Control Arm Bushing Set Varies $60–120

Restoration Guides

The bigger jobs: step-by-step, with parts lists, tools, and the mistakes to avoid.

DIY Maintenance

The routine work you can do on a Saturday with hand tools and jack stands.

Torque Specs

Values for common service jobs. Check the source listed for each table, and your own manual, before you torque anything critical.

Engine

Component Torque Spec Notes
Cylinder Head Bolts 54 ft-lbs (73 Nm) + 90° Cold engine, new bolts
Timing Belt Tensioner 33 ft-lbs (45 Nm) -
Water Pump Bolts 15 ft-lbs (20 Nm) -
Spark Plugs 18-22 ft-lbs (25-30 Nm) -
Valve Cover Nuts 7 ft-lbs (10 Nm) -
Oil Drain Plug 22 ft-lbs (30 Nm) Replace washer
Exhaust Manifold Nuts 18 ft-lbs (25 Nm) -

Suspension

Component Torque Spec Notes
Wheel Lug Bolts (M14) 96 ft-lbs (130 Nm) Tighten in star pattern
Strut Top Nut 40 ft-lbs (54 Nm) -
Control Arm Bolts 65 ft-lbs (88 Nm) -
Tie Rod Ends 33 ft-lbs (45 Nm) Use new cotter pin
Steering Wheel Nut 33 ft-lbs (45 Nm) -

Brakes

Component Torque Spec Notes
Caliper Bolts 48 ft-lbs (65 Nm) -
Brake Line Fittings 11 ft-lbs (15 Nm) Do not overtighten

Parts & Suppliers

Where I'd shop for 924 parts: genuine, performance, used, and the specialists.

OEM Featured

Porsche Classic

Factory parts for classic Porsches—many 924 parts still available through the Classic program

Factory Original Genuine Porsche
Genuine OEM
OEM Featured

Pelican Parts

Deep 924 catalog with genuine and quality aftermarket parts

OEM Parts Tech Articles 924 Specialist
Free over $99
OEM

Sunset Porsche Parts

Porsche dealer parts department with competitive pricing on genuine parts

OEM Dealer New Genuine Parts
Fast shipping
Performance Featured

Lindsey Racing

Long-running Porsche performance shop—extensive 944/924 turbo expertise and parts

Turbo Upgrades Engine Parts Performance
Performance

Paragon Products

924/944 performance specialist with engine and suspension upgrades

Engine Builds Suspension
General

AutohausAZ

Large selection of replacement parts at competitive prices

Replacement Parts Maintenance Items
Free over $99
General

FCP Euro

Lifetime replacement guarantee on everything they sell

Lifetime Warranty OE Quality
Free over $49 Lifetime
Specialist Featured

924Board Store

Community-driven store with 924-specific parts, gaskets, and hard-to-find items

924 Exclusive Rare Parts Community Resource
Specialist

928 International

While focused on 928s, carries many shared transaxle parts for 924/944

Transaxle Parts Electrical
Specialist

Porscheshop UK

UK-based specialist with excellent 924/944 coverage

European Parts Rare Items
International
Used/NOS Featured

924Board Classifieds

The go-to marketplace for used 924 parts—active enthusiast community

924 Exclusive Community Vetted
Used/NOS

Rennlist Classifieds

Large Porsche community marketplace with 924/944 section

Forum Marketplace Wide Selection
Used/NOS

eBay Motors

Global marketplace for used and NOS 924 parts

Used Parts NOS Global Sellers
Used/NOS

Car-Part.com

Search nationwide salvage yard inventory for 924 parts

Salvage Parts Low Cost

Community Resources

Where 924 owners hang out: forums, YouTube channels, and clubs worth your time.

Own a 924?

Track it in My Garage

Add your car and you get a 924 service schedule with intervals already filled in, a restoration tracker organized by system, and a log of every job and what it cost. It's free, and it's the same on your phone and your laptop.