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Failing hydraulic lifters announce themselves with a cold-start tick, then misfire codes that never clear. The 24-piece hydraulic lifter set from Koeep replaces all 24 intake and exhaust lash adjusters across both cylinder heads in one order, covering the DOHC 24-valve 6G72, 6G74, and G6CU/G6CT engines. Below: fitment, hard specs, DTC mapping, and the oil discipline this kit demands.

Fitment: One Kit, Three Engine Families

The set covers DOHC 24-valve heads on these platforms:

• Mitsubishi 6G72 3.0L DOHC 24V — 1991–1999 3000GT and Dodge Stealth, turbo and non-turbo
• Mitsubishi 6G74 3.5L — same shared architecture
• Hyundai-Kia G6CU / G6CT 3.5L DOHC — 2001–2006 Hyundai Santa Fe, 2001–2007 Terracan, 2002–2006 Kia Sorento

OEM cross-references: MD377054 (Mitsubishi Genuine) and 24610-33050 (Hyundai/Kia Genuine). Fitment is verified against the Mitsubishi ASA and Hyundai Kia Global Parts Catalog, 2026 edition. The product page carries the full application table — check yours before you order.

What It Does Not Fit

This is a DOHC-only kit. SOHC 12V 6G72 variants — the Montero and Diamante base engines — use a different lash adjuster design, and generic sets are often mislabeled on exactly this point. For SOHC V6 applications, use the dedicated lifter set for the 95–10 Montero Sport and 91–05 Dodge Stratus V6 instead.

Specification Table

Every figure below comes from the kit's published technical data, with OEM values shown for comparison.

Why These Lifters Fail

The weak point on the 6G72 and 6G74

The dominant high-mileage failure is HLA internal check-valve spring fatigue. A worn check valve lets oil drain from the lifter's internal reservoir overnight, pushing bleed-down past the OEM threshold of 0.008 inch/hour at 100°C. The lifter starts the day collapsed: startup tick, lazy valve events, misfires.

The material upgrade

1990s OEM Mitsubishi lifters (MD377054) used chromoly, case-hardened, with plunger bores around Ra ≤ 0.10 µm. This kit moves to high-carbon bearing-grade steel with an induction-hardened nose at 58–62 HRC and bores micro-polished to Ra ≤ 0.05 µm. The check valve runs hardened AISI 440C stainless to resist the crankcase moisture and acid that modern E10–E15 ethanol blends generate.

The ±1.5 µm plunger-to-body clearance compensates for the higher oil gallery temperatures documented in the transverse-mounted Santa Fe versus the longitudinal 3000GT layout. The G6CU — a licensed derivative of the 6G74 casting — shares the identical 12.00 mm lifter bore at all 24 positions. Demand for retrofits that out-build OE material specs helps drive the valve lifter market's projected 8.98% CAGR through 2033.

DTC Cross-Reference

Collapsed or slow HLAs shift valve lift and cam timing enough to store real codes. This set directly resolves or prevents:

• P0020 / P0021 — camshaft position actuator circuit/performance; fires when collapsed HLAs push cam timing deviation past 5°
• P0026 — intake valve control solenoid range/performance (Bank 1); common on the Santa Fe G6CU when intake bleed-down alters effective valve duration
• P0300–P0306 — random through cylinder-specific misfire; the primary consequence of HLA failure, caught via crankshaft acceleration fluctuation monitoring
• P0011 / P0022 — cam timing over-advanced/over-retarded; secondary codes when HLA pump-up at high RPM hangs valves open
• Cold-start lifter tick — the audible HLA bleed-down symptom itself

From the 2026 model cycle, valvetrain parts face scrutiny under SAE J1979-2 (OBDonUDS) diagnostic compatibility. These lifters hold valve events inside the PCM's expected ±2° crankshaft angle window, keeping closed-loop misfire detection accurate and false P0300–P0306 flags off across ISO 15031 PID frameworks.

Diagnose Before You Order

The 30-second cold tick

Overnight, oil drains from the lifter's reservoir through a worn check valve. At cold start the lifter runs collapsed until pressure rebuilds and the noise fades — roughly 30 seconds is early stage. If the tick runs past 90 seconds or shows up at hot idle, expect 4–6 lifters already past the 0.008 inch/hour bleed-down threshold.

A scan tool running SAE J1979-2 may log an early P0026 before you hear anything, because UDS polling catches the subtle cam timing deviation that inconsistent lash creates.

P0304 on a 3000GT

On the 6G72 DOHC, cylinder #4 works the rear bank's hottest thermal zone. A collapsed or slow-bleeding intake HLA there cuts effective valve lift by 0.006–0.012 inch, disturbs the air-fuel charge, and fires P0304. P0300 follows as the PCM chases fuel trim across neighboring cylinders.

Before condemning coils or injectors, run a running compression test at 2,500 RPM. If cylinder #4 dips more than 15% against the front bank average and recovers as RPM climbs, the lifters are the root cause. Replace as a set — the full 24-piece kit keeps both banks balanced and protects the 6G72's hollow-ground cam profiles from uneven lobe wear.

Oil Spec: The Deal-Breaker

These HLAs are engineered around 5W-30 or 5W-40 viscosity at operating temperature. To reach the projected 120,000–150,000 mile service life, run API SP full synthetic and hold 5,000-mile oil change intervals — the extended cycles fleet operators are adopting for these platforms through 2030.

Watch the G6CU specifically: it wears lifters faster on conventional 5W-30 stretched past 4,500-mile intervals, so shorter synthetic cycles are cheap insurance.

Why 0W-20 Fails Here

0W-20's high-temperature high-shear (HTHS) viscosity falls below 2.6 cP — too low to hold the hydrodynamic oil wedge inside the 12.00 mm bore above 4,500 RPM. Expect plunger cavitation and accelerated check-valve seat erosion. Run API SP 5W-30 full synthetic (HTHS ≥ 3.0 cP), or 5W-40 in ambient temperatures above 95°F.

VR-4 and Stealth R/T Turbo Notes

The 6G72-T twin-turbo heads share the identical 12.00 mm lifter bore and oil gallery placement with the naturally aspirated DOHC engine, and Mitsubishi never split HLA part numbers between turbo and non-turbo 24V engines — both use MD377054.

The Koeep 24-piece kit therefore fits the 1991–1999 3000GT VR-4 and Dodge Stealth R/T Turbo directly. Above 14 psi of boost, pair it with upgraded valve springs to prevent HLA pump-up at sustained high-RPM operation above 7,000 RPM.

Covering More of Your Fleet

Running mixed Mitsubishi and Chrysler V6 stock? Koeep also lists a 24-piece lifter set for Dodge, Mitsubishi, and Chrysler 2.5, 3.0, 3.5, and 3.8 V6 engines, so you can standardize on one precision spec across platforms.

For everything else, browse the auto and motorcycle parts catalog, or read the complete alternator guide for the 2015 Lancer Evolution Final Edition to cover charging-system maintenance on newer Mitsubishi platforms.

Need bulk or fleet quantities? Request a quote, email support@koeep.com, or message the team on WhatsApp.

Frequently Asked Questions