Hyundai i30: 2.0 petrol (G4GC) timing belt — interference engine, a snapped belt ruins it

This applies to the 2.0-litre G4GC petrol engine, which is what most Australian and New Zealand FD i30 petrol cars have; the 1.4 and 1.6 petrol engines use a chain instead and are not affected. The G4GC drives its camshafts with a rubber belt and it is an interference design, so if the belt breaks the valves and pistons collide and the engine is scrap. Documented failures cluster from around 90,000 km when the belt is left in. Nobody can tell a tired belt from a fresh one by looking through the cover, and the belt is hidden behind the accessory drive, so the entire inspection is the paperwork. The job is cheap compared with the consequence — a belt, tensioner and water pump kit fitted is a fraction of a replacement engine.

• No timing belt entry in the service book anywhere near 90,000 km
• A rough, flapping or slapping noise from the belt end of the engine
• Engine cranking freely but not starting after a bang or a stall
• Rough running or a misfire that appeared suddenly
• Rubber dust around the front of the engine

1. 1

   Open the service book and look for a timing belt entry with the kilometres it was done at, and take a photo of the invoice if there is one — an FD i30 with a 2.0 petrol engine and no belt history is a car you should price as though the job is due today.

2. 2

   Check the badge on the boot and the engine size on the registration paperwork to confirm you are actually looking at a 2.0 rather than a 1.6, because the smaller engines use a chain and this fault does not apply to them.

3. 3

   Start the car cold with the bonnet up and listen at the accessory belt end for a slapping or flapping noise rather than a smooth whirr.

4. 4

   Ask the seller directly when the belt was last replaced and who did it.

Parts involved: Timing belt.

$600 to $7,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

• “When was the timing belt last replaced, and at what kilometres?”
• “Was the water pump and tensioner done at the same time?”
• “Is this the 2.0-litre engine, and do you have the invoice for the belt?”

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

• What-Breaks.com — 'Hyundai i30 FD: problems and weaknesses (2007-2012)': G4GC 2.0 timing belt failure from 90,000 km, interference engine, valve-to-piston collision
• Hyun Engines (Australia) — 'Hyundai i30 engine problems explained': G4GC 2.0 documented weaknesses versus the chain-driven 1.6 G4FC