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G6BA Hyundai-Kia Delta V6 platform Petrol 1998-2008

Hyundai-Kia Delta V6 platform G6BA — 2.7L V6 24V DOHC Engine

2.7L V6 24V DOHC · 167-175 hp · 245-248 Nm

The G6BA is the 2.7-litre Delta V6 petrol engine from Hyundai-Kia, a 24-valve DOHC unit built from 1998 to 2008. It is fitted to the Hyundai Sonata EF, Trajet, Coupe GK and Santa Fe SM, and to the Kia Magentis and Optima. It is an interference engine with a timing belt, and the tensioner and idler bearings tend to fail before the belt itself, which bends valves. Other common jobs are upper intake manifold gasket failure with misfires and coolant in the ports, the rear coolant crossover pipe leaking with no visible trace, oil use through valve stem seals, EGR fouling, crank sensor faults and throttle body carbon causing idle hunting. This page gives torque figures for the head bolts, crank pulley bolt, upper intake manifold bolts and camshaft bearing caps.

Confirm timing belt condition and history first; a one-bank misfire after a skipped tooth means stopping cranking and checking cam timing. Unexplained coolant loss with no white smoke points at the rear crossover pipe and the upper intake gasket before any head gasket diagnosis. Hot stalling or no-start with P0335/P0336 calls for the crank sensor and its wiring. Idle hunting after throttle body cleaning needs the idle relearn.

Check first

  • Timing belt kit with tensioner, idler and water pump at 90000 km.
  • Rear coolant crossover pipe and O-rings on coolant loss without white smoke.
  • Cooling system pressure test before pulling the upper intake for a gasket.
  • Crank position sensor and harness chafing when it stalls hot.
  • Oil grade: 5W-30 at ACEA A3 minimum; mineral 10W-40 sludges the engine.

Engine overview

Manufacturer
Hyundai-Kia Delta V6 platform
Displacement
2.7 L
Configuration
V6 24V DOHC
Power
167-175 hp
Torque
245-248 Nm
Production years
1998-2008
Fuel type
Petrol

Vehicles with this engine

Hyundai Sonata EF/NF (2001-2007) Hyundai Trajet (2000-2008) Hyundai Coupe GK (2002-2008) Hyundai Santa Fe SM (2001-2006) Kia Magentis (2001-2006) Kia Optima (2001-2006)

Known failures & weak points

Upper intake manifold gasket failure at 80,000-120,000 km: OEM composite gaskets shrink and crack from thermal cycling, causing rough idle, P0300 misfire codes, and coolant seeping into intake ports. Replacement requires full upper manifold removal; confirm by pressure-testing the cooling system before teardown.
Timing belt tensioner pulley bearing seizure at 90,000-130,000 km: The hydraulic tensioner and idler pulley bearings fail before the belt itself, causing a high-pitched squeal progressing to belt skip and catastrophic valve damage. This is an interference engine — belt failure = bent valves on all 6 cylinders. Always replace tensioner, idler, and water pump as a kit at every belt change.
Oil consumption via valve stem seals at 100,000-160,000 km: Hardened OEM valve stem seals (particularly exhaust side) cause blue smoke on cold start and deceleration, consumption up to 0.5L/1,000 km. Full head removal required for seal replacement; while apart, inspect valve guides for wear. Confirm with leak-down test before committing to repair.
EGR valve carbon fouling at 80,000-100,000 km on markets with EGR-equipped variants: Sticky EGR causes rough idle, P0401/P0402 codes, and hesitation under light throttle. Check EGR cooler for internal coolant leak simultaneously — a known secondary failure on high-mileage units.
Crankshaft position sensor (CKP) failure at 100,000-150,000 km: OEM sensor (mounted on block near crank pulley) is vulnerable to heat soak and vibration, causing intermittent no-start, stalling at operating temperature, and P0335/P0336 codes. Symptoms worsen when engine is hot. aftermarket units have high early-failure rate on this application. Inspect wiring harness routing for chafing against block.
Coolant leak from rear coolant pipe/crossover tube at 120,000-180,000 km: The rear coolant crossover pipe (between cylinder banks, accessible only from below with intake removed) develops pinhole corrosion and O-ring failure. Symptom is unexplained coolant loss with no visible external leak. Often misdiagnosed as head gasket. Replacement requires partial intake removal; use silicone O-ring upgrade kit.
Throttle body carbon buildup causing idle surge at 80,000-120,000 km: IAC (Idle Air Control) passage and throttle plate accumulate heavy carbon deposits, causing hunting idle (400-1,100 RPM oscillation), stalling in gear, and cold-start hesitation. Clean throttle body and IAC with dedicated cleaner; perform idle relearn procedure via OBD scanner (Hi-Scan or GDS) after cleaning — idle will not stabilize without relearn on this ECU.
Power steering pump seal failure and whine at 100,000-140,000 km: OEM pump shaft seal weeps fluid onto accessory belt, causing belt slip and PS fluid consumption. Early symptom is groan on full lock that disappears after warm-up. Resealing is not cost-effective; Flush entire PS system with Hyundai PSF-3 fluid on replacement to avoid contaminating new pump seals.

Common torque specifications

Head Bolts Step 1: 30 Nm; Step 2: +60° angle; Step 3: +45° angle — TTY bolts, replace on every removal, do not reuse unconfirmed
Crank Pulley Bolt 195 Nm (no angle, non-TTY — use impact gun with torque stick or breaker bar with flywheel lock tool) unconfirmed
Intake Manifold Upper Bolts 18-20 Nm (M8 bolts, torque in cross pattern, do not overtighten composite manifold) unconfirmed
Camshaft Bearing Cap Bolts 10-12 Nm (M6, tighten in sequence from center outward — critical to prevent cap cracking) unconfirmed

Figures marked unconfirmed could not be cross-checked against a workshop source. Verify against the vehicle’s own documentation before tightening.

Service intervals

Timing Belt Km 90000
Oil Change Km 10000
Oil Spec 5W-30 API SL/SM or ACEA A3/B4 (Hyundai OEM spec 00232-12100)
Oil Capacity L 4.5
Coolant Spec Hyundai Genuine Long Life Coolant (LLC) OAT type, pre-mixed 50/50, pink — do NOT mix with green IAT coolant

Pro tips from the field

This is a true interference engine with zero valve-to-piston clearance margin — always verify timing belt condition at purchase regardless of claimed service history. A skipped tooth on the belt produces a characteristic 'machine-gun' misfire on one bank only; if you see this symptom, do NOT crank further. Remove valve covers and verify cam timing with degree wheel before attempting restart.
The rear coolant crossover pipe failure is the most commonly missed diagnosis on this engine. Before condemning a head gasket on a G6BA with unexplained coolant loss and no white exhaust smoke, remove the lower intake plenum and inspect the rear pipe and its O-rings.
When replacing the timing belt, the water pump impeller is plastic and routinely fails between belt changes — always replace it as part of the kit even if it appears serviceable. A pump failure after a fresh belt change is an avoidable comeback that destroys shop credibility.
Idle relearn after throttle body service is mandatory and must be performed with a compatible scan tool (Hyundai Hi-Scan Pro, GDS Mobile, or Launch X431 with Hyundai license). The procedure: coolant temp above 80°C, A/C off, all loads off, idle for 10 minutes without touching throttle, then perform 'Idle Speed Learning' function in ECU adaptation menu. Skipping this step results in a customer return complaint of hunting idle within 24 hours.
Oil specification is important on this engine — using 10W-40 mineral oil (common in some Eastern European markets) accelerates sludge buildup in the timing system. Always use a full or semi-synthetic 5W-30 meeting ACEA A3 minimum, and if buying a used G6BA, perform a hot oil flush before the first service to clear accumulated sludge.

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Who makes these pages, and how

TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

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Workshop data on this page last updated 22 Aug 2026.