HiAce Van: Oil leak / seepage
Suspect the oil pan gasket first (the sump joint). Just as common is seepage from the top of the engine (valve cover and similar) that runs down and shows underneath after a drive. Fewer cases, but if the inside of a rear wheel is oily, it may be differential oil leaking past the rear axle shaft seal onto the brake shoes. A few cases involve oil escaping with the air-con refrigerant. Work from the position and colour of the drips on the ground.
What to suspect, in order
- How to tell (things you can check yourself)
- With the engine cold, pull the dipstick and check whether the level is near the minimum. If you're topping up more often than before, it's escaping somewhere. Feel under the engine for oily residue.
- If you leave it
- Low oil means poor lubrication and internal damage. The oil light may come on.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- Typical model years and mileage
- Reports increase with vehicle age and mileage.
- How to tell (things you can check yourself)
- Look along the joint of the pan-shaped part under the engine for seepage. Usually noticed as spots where you park, or a burnt smell after driving.
- If you leave it
- As the seepage spreads, oil level drops and oil on nearby rubber parts and wiring speeds their deterioration.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- Typical model years and mileage
- More likely on older, high-mileage vehicles.
- How to tell (things you can check yourself)
- Air-con weaker than before, or slow to blow cold? Refrigerant carries oil, so pipe joints may look oily.
- If you leave it
- Running the system without refrigerant stresses the A/C components.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- Typical model years and mileage
- More common on older vehicles.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- How to tell (things you can check yourself)
- Look for oil seepage on the inside of the rear wheels behind the rim, or spray marks on the inner tyre. A low hum from the rear while driving is another sign.
- If you leave it
- Continued leaking starves the axle bearings and damages surrounding parts.
- Typical repair cost
- Too few cases with a recorded price to give a figure
- Typical model years and mileage
- More likely on high-mileage vehicles and those carrying heavy loads.
These are possibilities. Where it's actually coming from is confirmed by an inspection.
FAQ
- It's only seeping — can I drive for a while?
- Depends on amount and location. If it leaves spots on the ground or the dipstick reads near minimum, get it checked soon. Make a habit of checking the level before driving.
- How long does the repair take?
- Depends where it's coming from. Gasket replacement involves disassembly and may take days including parts. First step is locating the source.
- Will it pass the inspection?
- Depends on degree and location. Dripping leaks, or oil reaching the brakes, must be fixed and rechecked.
- Is weak air-con related to the oil leak?
- Separate system, but refrigerant oil can leave oily residue at pipe joints, so it can look similar. We tell the two apart.
Sources
- MLIT Vehicle Defect Information Hotline (Japan)（7 cases）
- Repair shop blogs (Japan)（1 cases）
Created by processing the Vehicle Defect Information Hotline data (Ministry of Land, Infrastructure, Transport and Tourism, Japan) (https://renrakuda.mlit.go.jp/renrakuda/opn.html)
No text is quoted from these sources. Only the facts of each case (model, symptom, cause, cost) are aggregated.
Reviewed by Tama Inc. (workshop certified by the Kanto District Transport Bureau) Reviewed on 2026-09-11 Updated 2026-09-11
This page shows what to suspect first, based on aggregated nationwide repair cases and our own experience. Always confirm the cause with an inspection. Repair costs are medians and ranges from the cases; they vary by vehicle condition, region and workshop.
Check leaks from the top down: valve cover first, then the sump joint. If the inside of a rear wheel is oily, that's not engine oil — it's diff oil from the axle shaft seal.