Parts for your 2004 Mitsubishi Pajero-Oil pump

2004 Mitsubishi Pajero oil pump — what it does and when to service it

Technical sources confirm the 2004 Mitsubishi Pajero is fitted with an engine oil pump and absolutely relies on it. The Mitsubishi Pajero NM/NP Workshop Manual (2000–2006), the Mitsubishi ASA electronic parts catalogue, and general references like Haynes’ Montero/Shogun/Pajero manual and Autodata list a crankshaft-driven internal gear/trochoid oil pump for the common 2004 engines — the 3.2 DI-D 4M41 diesel and the 3.5/3.8-litre V6 petrols (6G74/6G75). That means the oil pump is relevant to every 2004 Pajero variant.

The pump’s job is simple but critical: push the right volume of oil, at the right pressure, through the galleries to bearings, camshafts, lifters and the turbo (on the DI-D). On these Pajeros, the pump is integrated in the front cover and driven directly off the crank, so it’s robust and happy to work hard — as long as it’s fed clean oil.

As part of normal servicing, the best protection for the pump is regular oil and filter changes using the correct spec and grade for local climate. For most Aussie and NZ use, that means quality diesel-rated oil for the 4M41 and the right petrol spec for the V6s, changed at sensible intervals (typically 10,000–15,000 km or 6–12 months, whichever comes first). Letting oil go long and sludgy can starve the pickup and wear the pump’s internal gears.

• Warning signs worth a look: a flickering oil light at idle when hot, rattly lifters on cold start, rumbling under the front cover, or low pressure on a mechanical gauge.
• Good workshop checks: inspect the pickup strainer for sludge, verify pressure with a gauge, and check for front crank seal weep while the belts/cover are off.

Replacement is not a quick driveway job. Access usually means front-end disassembly (crank pulley off, timing belt on V6 or timing cover on 4M41, sump or pickup access as needed). A competent mechanic will:

1. Inspect and clean the pickup and sump.
2. Fit a new pump or overhaul kit with fresh O-rings/gaskets and front crank seal.
3. Prime the pump with clean oil before starting.
4. Refill with the correct oil, then verify pressure hot and cold.

Look after the oil and the oil pump will look after the engine, whether the Pajero’s towing a van up the Bruce or crawling a South Island track.

Popular questions about 2004 Mitsubishi Pajero oil pumps

Does the 2004 Pajero actually have an oil pump?
Yes. Factory workshop information and the Mitsubishi ASA parts catalogue show a crank-driven internal gear (trochoid) oil pump on the 3.2 DI-D 4M41 diesel and the 3.5/3.8 V6 petrol engines. It’s built into the front cover and is essential for engine lubrication and turbo feed on the diesel.

How often should the oil pump be replaced?
There’s no fixed replacement interval. The pump generally lasts the life of the engine if oil changes are kept up. Replacement is considered if hot-idle oil pressure falls below spec, there’s excessive internal wear, or the pickup was blocked and the engine suffered oil starvation. Many owners renew the pump when doing a major front-end overhaul.

What symptoms point to a failing oil pump on a 2004 Pajero?
Common red flags include a flickering oil warning lamp at hot idle, tapping lifters on start-up that don’t quieten quickly, rumbling from the timing/front cover area, or verified low oil pressure on a mechanical gauge. Always rule out thin/old oil and a clogged pickup before condemning the pump.