Head Gasket Replacement
Replace the cylinder head gasket that seals the engine block to the cylinder head. A blown head gasket causes overheating, white exhaust smoke, coolant loss and milky oil. One of the most expensive common repairs because the engine must be partly dismantled (6-12 hours labour).
Cost by Brand (AUD)
| Brand | Total | Labour | Parts |
|---|---|---|---|
| MG | $1440-$2240 | $860-$1460 | $430-$780 |
| Chery | $1476-$2296 | $890-$1490 | $440-$800 |
| Haval | $1494-$2324 | $900-$1510 | $450-$810 |
| BYD | $1530-$2380 | $920-$1550 | $460-$830 |
| GWM | $1530-$2380 | $920-$1550 | $460-$830 |
| LDV | $1584-$2464 | $950-$1600 | $480-$860 |
| Suzuki | $1620-$2520 | $970-$1640 | $490-$880 |
| Mitsubishi | $1656-$2576 | $990-$1670 | $500-$900 |
| Hyundai | $1700-$2800 | $1020-$1820 | $510-$980 |
| Kia | $1700-$2800 | $1020-$1820 | $510-$980 |
| Nissan | $1764-$2744 | $1060-$1780 | $530-$960 |
| Toyota | $1800-$2800 | $1080-$1820 | $540-$980 |
| Honda | $1836-$2856 | $1100-$1860 | $550-$1000 |
| Mazda | $1900-$3000 | $1140-$1950 | $570-$1050 |
| Ford | $2000-$3500 | $1200-$2280 | $600-$1220 |
| Jeep | $2016-$3136 | $1210-$2040 | $600-$1100 |
| Skoda | $2070-$3220 | $1240-$2090 | $620-$1130 |
| Subaru | $2500-$4500 | $1500-$2920 | $750-$1580 |
| Volkswagen | $2800-$5000 | $1680-$3250 | $840-$1750 |
| Audi | $2800-$5000 | $1680-$3250 | $840-$1750 |
| BMW | $3000-$5500 | $1800-$3580 | $900-$1920 |
| Mercedes-Benz | $3500-$6000 | $2100-$3900 | $1050-$2100 |
Symptoms of a Blown Head Gasket
Tick off what you're seeing — two or more of these usually means the gasket has failed and needs a compression test to confirm.
- ✓White smoke from the exhaust. Thick, sweet-smelling white smoke that keeps going once the engine is warm — coolant burning in the cylinders.
- ✓Milky, frothy oil. A mayonnaise-like residue on the oil cap or dipstick — coolant mixing with the oil.
- ✓Engine overheating. Temperature gauge climbing into the red for no obvious reason, often recurring.
- ✓Coolant loss with no visible leak. The coolant level keeps dropping but you can't see a drip — it's being burned or pushed into the oil.
- ✓Bubbles in the radiator or overflow. Constant bubbling with the cap off, or a coolant overflow tank that keeps overfilling — combustion gas entering the cooling system.
- ✓Rough idle and loss of power. Misfiring, poor compression or a sweet smell from the exhaust as cylinders lose their seal.
Is It Worth Fixing?
Compare the estimated head gasket replacement cost against what your car is worth today.
- Est. head gasket replacement
- $1,440–$6,000
- 50% of car value
- $4,000
- Repair vs value
- 47%
The repair is a reasonable share of your car's value. If the car is otherwise sound, fixing the head gasket replacement usually makes sense.
Repair the Gasket or Replace the Engine?
Because a head gasket job is so labour intensive, it can cost as much as — or more than — the car is worth on older, high-km vehicles. When that happens, a replacement engine is a real alternative:
- •Reconditioned engine — typically $2,500-$5,000 fitted. Comes with a warranty and is the safest bet if you plan to keep the car for years.
- •Used (second-hand) engine — typically $1,500-$3,500 fitted from a wrecker. Cheaper, but check the km and warranty.
- •Repair the gasket — best when the engine is otherwise healthy, the car has reasonable value, and the head isn't cracked or badly warped.
Either way, get a compression test and a cooling-system pressure test first — and always get three written quotes before committing to a job this size.
Tips
- ✓Confirm the diagnosis first — a compression test and cooling-system pressure test are cheap and avoid a $2,000+ job you don't need
- ✓Always machine (resurface) the cylinder head and fit new head bolts; reusing old bolts is a common cause of repeat failure
- ✓Subaru EJ25 engines (Impreza, Forester, Outback ~2000-2011) are notorious for head gasket failure — budget for it when buying
- ✓Replace the timing belt, water pump and coolant while the engine is apart to save hundreds in labour later
- ✓If the repair costs more than the car is worth, compare against a used or reconditioned engine before deciding