Parts for your 1998 Daihatsu Gran move-Oil cap

1998 Daihatsu Gran Move oil cap — what it does and how to look after it

Technical sources confirm the 1998 Daihatsu Gran Move is fitted with an engine oil filler cap and absolutely relies on it. The Daihatsu G300-series Workshop Manual (Gran Move/Pyzar), the factory Electronic Parts Catalogue for G30# models, and the 1998 Owner’s Manual all specify a screw-in, sealed oil filler cap mounted on the cam/rocker cover. So an oil-cap is relevant and used on this vehicle.

On the Gran Move, the oil cap’s job is simple but critical: it seals the top of the engine so fresh oil can be added cleanly, and it keeps dust, moisture, and grit out of the crankcase while the engine breathes via the PCV system. With a good seal, the engine maintains the right crankcase conditions and avoids oily mist under the bonnet. If the cap’s gasket hardens or the cap goes missing, expect oil seepage, smells, and the risk of unfiltered air being drawn into the engine.

As part of regular servicing in Australia and New Zealand, it’s a good shout to check the Gran Move’s oil cap every time the oil and filter are changed (typically every 10,000 km or 6 months, depending on use). The cap on G30-series engines is a screw-in type with a rubber sealing ring. Hand-tight is all that’s needed—no tools—just a firm nip until the gasket seats. A light wipe of clean engine oil on the gasket helps it seal and come off easily next service.

• Replace the cap if the rubber seal is cracked, flattened, or missing.
• Look for oil mist or weeping around the cap area