G4KJ engine problems: bearing recalls, oil use and what to check first
Warning signs
- A rhythmic knock that speeds up with the engine: possible bearing wear. Stop driving.
- The engine or oil pressure warning light.
- Stalling while driving.
- Oil dropping fast between services, and a tap or knock from cold.
Common causes on the G4KJ
The G4KJ is the 2.4 litre direct-injected petrol in many Hyundai and Kia models, including the i45, Santa Fe, Sonata, Optima and Sportage. Three problems are documented in the sources we checked.
Check before you buy
Our engine is the late G4KJ for 2016-on vehicles. Earlier vehicles may need a different version, so confirm from the VIN and the code on the block. See G4KG or G4KJ engine.
Repair, rebuild or replace?
Once a bearing has knocked or the engine has seized, the crankshaft and bearings are damaged and usually more besides. That means a rebuild with machining or a new engine. Scored bores are the same. Ask your mechanic for the test results first. See engine tests before replacing an engine.
What a G4KJ replacement costs
Hyundai / Kia G4KJ long bare timed engine: long bare timed Was AUD 7,850, now AUD 6,850
Read the full guide and supporting detail
What goes wrong with the G4KJ?
The G4KJ is the 2.4 litre direct-injected petrol in many Hyundai and Kia models, including the i45, Santa Fe, Sonata, Optima and Sportage. Three problems are documented in the sources we checked.
What were the Australian recalls?
- Hyundai, 2017: 9,672 i45 and Santa Fe DM 2.4 GDI engines were recalled because debris from assembly could cause engine failure and a sudden stop.
- Kia, 2017: 4,963 Optimas built 2010 to 2014 were recalled because machining errors could wear the bearings early. A small number of Sorentos were covered by a matching recall.
Kia's US bulletin explained the cause: metal swarf left in the crankshaft oil passages and an uneven finish on the crankpins could restrict oil to the connecting rod bearings. The fix was inspection and, where needed, a replacement engine block assembly.
If your vehicle is in one of those groups, have a Hyundai or Kia dealer check the VIN before you buy anything.
What about oil use?
On the Sonata LF 2.4 GDI, high oil use (more than a litre per 1,000 km) and a loud knock from cold have been put down to scored cylinder bores. The fix given is a rebuild or a new block.
What are the class actions about?
Federal Court class actions against Hyundai and Kia name G4KJ vehicles. They are allegations, not findings, and Hyundai denies most of the claims. We mention them so you know they exist, not as a view on the outcome.
What are the warning signs?
- A rhythmic knock that speeds up with the engine: possible bearing wear. Stop driving.
- The engine or oil pressure warning light.
- Stalling while driving.
- Oil dropping fast between services, and a tap or knock from cold.
Is it a repair or a new engine?
Once a bearing has knocked or the engine has seized, the crankshaft and bearings are damaged and usually more besides. That means a rebuild with machining or a new engine. Scored bores are the same. Ask your mechanic for the test results first. See engine tests before replacing an engine.
Which G4KJ do you need?
Our engine is the late G4KJ for 2016-on vehicles. Earlier vehicles may need a different version, so confirm from the VIN and the code on the block. See G4KG or G4KJ engine.
What G4KJ engine does Reco list?
A new late G4KJ timed long bare motor, listed at $6,850 on 15 October 2026. The high-pressure fuel pump and injectors come across from your old engine, so have them checked. See the G4KJ engine page.
Ask us about your G4KJ
Use the enquiry form with the make, model, year, series and VIN. Or call 02 9737 0105.
