Mitsubishi Delica D:5: common faults & what to check

Can't confirm for this car

Unconfirmed. This entry does not match our record of which engines and years this model was sold with, and is awaiting review. Confirm it against the car before acting on it.

The 4N14 2.2-litre diesel fitted to Delica D:5 imports develops a timing chain rattle similar to Mitsubishi's other 4Nx-series engines. The chain tensioner is oil-pressure dependent and degrades with age, particularly on vehicles with extended or infrequent oil changes. Documented on Japanese Delica owner forums and reported by NZ independent mechanics who service the growing JDM Delica D:5 import fleet. The fault is progressive — ignored rattles lead to full chain replacement.

Example of the part — not this vehicle

Where to look: Front of engine, timing chain cover

Parts involved: Timing chain.

Can't confirm for this car

The 4M40 2.8 diesel is susceptible to head gasket failure on high-mileage examples, typically presenting above 200,000 km or after overheating events. The alloy head is prone to warping if the engine has ever run hot, and the factory head bolt torque specification leaves little margin once the gasket begins to compress with age. Head gasket failure allows combustion gases into the coolant, pressurising the cooling system and causing rapid coolant loss. It is one of the most commonly reported terminal failures on neglected L400 Delicas presented for WOF.

Example of the part — not this vehicle

Where to look: Head gasket between the 4M40 cylinder head and engine block, accessible from the top of the engine after removing the valve cover

Parts involved: Head gasket.

Can't confirm for this car

The Invecs-III JATCO-sourced CVT fitted to 4B12 2.4L petrol Delica D:5 models produces a shudder or judder under light throttle at low speed when CVT fluid degrades or overheats from towing or sustained off-road use. The CVT fluid should be changed every 40,000-60,000 km but many JDM-sourced examples arrive with fluid well beyond this interval. A fluid change resolves early cases; persistent judder after a fluid change indicates internal clutch pack or steel belt wear requiring CVT rebuild or replacement.

Where to look: CVT unit under centre floor, mid-vehicle

Parts involved: Clutch.

Can't confirm for this car

The L400 Delica fitted with the automatic transmission uses electronically controlled shift solenoids in the valve body to manage gear selection. These solenoids fail with age and high mileage, typically due to varnish deposits from degraded automatic transmission fluid blocking the solenoid orifices, or internal solenoid coil failure. The result is incorrect gear engagement, harsh shifts, or the transmission defaulting to limp-home mode. The fault is common on any Delica where automatic transmission fluid changes have been skipped, and is frequently logged as a fault code in Japanese auction inspection sheets.

Where to look: Inside the automatic transmission valve body, accessed by dropping the transmission sump pan

Parts involved: Mechatronic / valve body.

Can't confirm for this car

The Delica D:5's Super Select 4WD or electronic shift-on-the-fly transfer case uses a small electric actuator motor and encoder to switch between 2H, 4H, and 4L modes. The plastic reduction gear cluster within the actuator is prone to stripping under the torque loads of mode-switching, particularly if the transfer is engaged at speed or if the motor runs against a mechanically blocked shaft. Worn encoder sensors can also cause the transfer case to hunt between modes or refuse to complete the shift, leaving the vehicle in an indeterminate state.

Where to look: Transfer case actuator motor bolted to the right rear of the transfer case unit, beneath the centre of the vehicle

Parts involved: Transfer case.

Can't confirm for this car

The hydraulic timing chain tensioner on the 4B12 2.4L MIVEC loses oil-film retention after extended service intervals or high mileage (typically above 150,000 km). On cold start, oil pressure takes several seconds to build, leaving the tensioner unable to maintain chain tension. This produces an audible metallic rattle from the front of the engine for 3–10 seconds before settling. Repeated cycling accelerates chain and guide wear. If left unaddressed the chain can skip a tooth, causing mistimed valve events, loss of power, and potential valve-to-piston contact on this interference engine. Grey imports arriving at 80,000–120,000 km Japanese odometer readings may still have original tensioners that are near end-of-life by NZ standards.

Example of the part — not this vehicle

Where to look: Front of engine, behind timing cover on the accessory-drive side

Parts involved: Timing chain.

Can't confirm for this car

The exhaust gas recirculation cooler fitted to later 4M40 engines is prone to internal cracking caused by thermal fatigue from repeated hot/cold cycles. A cracked cooler allows coolant to enter the EGR circuit and be drawn into the intake manifold, leading to gradual coolant loss and, in severe cases, hydrostatic lock risk. This is a well-documented failure mode across the 4M40 engine family in Pajero, Triton, and Delica applications.

Where to look: EGR cooler mounted on the left side of the 4M40 engine block, connected to the exhaust and intake manifold

Parts involved: EGR valve.

Can't confirm for this car

The 4N14 2.2L turbodiesel uses exhaust gas recirculation to reduce NOx emissions. The EGR valve and its passage accumulate carbon deposits from diesel blow-by, particularly in vehicles operated predominantly on short urban runs where exhaust temperatures remain low. Carbon build-up causes the valve to stick partially open or fail to open fully on command. A stuck-open valve recirculates excessive exhaust gas, diluting the air charge and causing rough idle, hesitation on acceleration, and increased smoke. A stuck-closed valve triggers P0401 (EGR flow insufficient detected) and may cause elevated NOx emissions that fail a vehicle inspection. The issue is accelerated on grey imports used for NZ urban shuttle duty after a prior JDM life of predominantly highway use.

Where to look: Exhaust gas recirculation valve mounted on the intake manifold, driver's side of the 4N14 engine

Parts involved: EGR valve.

Can't confirm for this car

The rubber O-ring seals on the injector return fuel pipes of the 4M40 2.8 diesel deteriorate with heat cycling and age. Failed seals allow diesel fuel to weep back along the return rail and contaminate the engine bay or mix with engine oil on high-mileage examples. The problem is endemic to the 4M40 engine family and is a routine finding on pre-purchase inspections of L400 Delicas over 150,000 km.

Example of the part — not this vehicle

Where to look: Top of the 4M40 engine along the injector return fuel rail, at each injector banjo fitting

Parts involved: Fuel injector.

Can't confirm for this car

The front suspension lower control arm ball joints on the Delica D:5 carry significant load given the vehicle's elevated kerb weight and all-wheel-drive configuration. The ball joint boot is exposed to road debris and water in off-road use; once the rubber boot tears, grease is expelled and abrasive contamination enters the joint, rapidly wearing the ball stud and socket. Progressive wear introduces play that causes vague steering, and a fully failed ball joint can separate, causing immediate loss of steering geometry and wheel collapse.

Example of the part — not this vehicle

Where to look: Lower end of each front suspension strut assembly, connecting the lower control arm to the steering knuckle

Parts involved: Ball joint.

Can't confirm for this car

The L400 Delica has known rust-prone areas in the outer floor sills and inner and outer rear wheel arches. The sill sections trap moisture and road debris, while the rear wheel arches are subject to stone chip damage that breaks through the factory paint and allows rust to establish. Vehicles used in coastal regions of New Zealand or those that have spent time in Japan's snowbelt provinces (where road salt is used) are significantly more affected. Structural sill rust can compromise the vehicle's rigidity and lead to WOF rejection. Rust in wheel arches is cosmetic in early stages but can spread to the structural chassis rails if left untreated.

Where to look: Outer floor sills running beneath the doors on both sides; inner and outer rear wheel arches; around rear door aperture flanges

Parts involved: Body corrosion.

Can't confirm for this car

The Delica D:5 uses a complex rear multi-link independent suspension with numerous rubber compliance bushes in the upper and lower lateral links and the toe-control arm. The inner rubber element of these bushes degrades through a combination of ozone cracking, oil contamination from differential or exhaust proximity, and cyclic fatigue, causing the rubber to delaminate from the metal sleeve. As the bush collapses, the rear wheel geometry shifts under load, producing unpredictable toe-out that causes the vehicle to track poorly and accelerates rear tyre wear.

Where to look: Rear subframe and multi-link arm pivot points on both sides of the rear axle

Parts involved: Differential.

Can't confirm for this car

The L400 Delica 4WD uses Birfield-type constant-velocity joints in the front axle shafts. These joints are robust but fail when the grease-retaining boots tear — a common occurrence on vehicles used off-road or with high mileage. Once a boot tears, grease is flung out and abrasive grit enters the joint, rapidly wearing the balls and races. Neglected joints eventually seize or fracture, leaving the vehicle undriveable. Boot deterioration accelerates from UV exposure in New Zealand conditions.

Where to look: Front axle shafts, both left and right birfield CV joints inboard and outboard of the front differential

Parts involved: CV joint and boot.

Can't confirm for this car

The front and rear brake calipers on the Delica D:5 use sliding guide pins coated with a high-temperature grease to allow the caliper to float and apply even pressure across both brake pads. In the New Zealand and Australian climate, road salt, brake dust, and water infiltration past the guide pin rubber boots cause the pin's chrome surface to corrode, binding the caliper in a partially applied position. A seized guide pin causes one pad to drag continuously against the rotor, producing asymmetric braking, accelerated pad and rotor wear on one side, and brake fluid overheating.

Where to look: Upper and lower guide pin bores in the brake caliper mounting bracket on all four corners

Parts involved: Brake disc and pads.

Can't confirm for this car

The Delica D:5 sliding door lower hinge bracket, roller guide, and sill track corrode in NZ's coastal and high-rainfall regions. Corrosion causes the door to become stiff or misaligned, dragging on the sill when opened. In advanced cases the lower roller bracket can fail entirely, leaving the door supported only by the upper track and creating a safety risk. Particularly prevalent on South Island and Northland examples and vehicles that have not had underbody protection applied.

Where to look: Sliding door lower roller bracket and sill track channel, right rear (driver-side in NZ)

Parts involved: Body corrosion.

Can't confirm for this car

The front differential output seals and front differential input (propshaft) seal on Delica D:5 4WD models are prone to weeping oil, particularly as the vehicles age past 150,000 km or if the differential oil has not been changed at recommended intervals. Seal degradation allows differential oil to leak onto surrounding components and can eventually lead to differential bearing damage if oil level drops significantly. Reported by NZ mechanics servicing the imported Delica fleet.

Where to look: Front differential, underneath vehicle behind front crossmember

Parts involved: Differential.

Can't confirm for this car

The power steering pump fitted to both the 4M40 diesel and 6G72 petrol L400 Delica uses rubber shaft and body seals that harden and weep with age. On vehicles over 15 years old, seal failure is routine rather than exceptional. A weeping pump seal allows power steering fluid to leak onto the front of the engine or onto the accessory belt, creating a fire risk and contaminating the belt. Continued operation with low fluid levels causes pump whine and accelerated pump wear. The fault is very common on any L400 Delica that has not had the power steering system serviced.

Where to look: Power steering pump mounted on the front of the engine, driven by the accessory belt on the driver's side

Parts involved: Steering rack.