Parts for your 2007 Mazda Premacy-Oil cap

2007 Mazda Premacy oil cap — purpose, fitment, and easy maintenance

Per Mazda’s own technical literature, an oil cap is absolutely fitted and required on the 2007 Mazda Premacy (also known as Mazda5). The 2007 Owner’s Manual (Maintenance and Care – Engine Oil) and the Mazda5/Premacy CR Workshop Manual for the MZR petrol and MZR-CD diesel engines both specify a screw-type oil filler cap located on the cam cover. So yes, this vehicle uses an oil cap, and it’s an essential sealing component of the engine’s lubrication system.

On this Premacy, the oil cap does the simple but critical job of sealing the filler neck so oil can’t splash out under the bonnet, while keeping dust, moisture, and grit from getting into the engine. It also helps the crankcase ventilation system behave as designed. A loose, cracked, or missing cap can lead to oil weeping around the top cover, a hot-oil odour, messy engine bays, and even rough running on some engines due to unmetered air affecting crankcase breathing.

For owners looking after their 2007 Mazda Premacy, treating the oil cap as a small service item pays off. During every oil change, the cap should be removed, the sealing surface wiped clean, and the rubber O-ring inspected. If the seal has gone hard or flat, or the cap shows heat cracks or a chewed thread, it’s time to replace it. There’s no fixed interval in the schedules, but genuine or quality OE-equivalent caps are inexpensive insurance against leaks and nuisance smells.

Fitting is straightforward: place the cap squarely on the filler neck and turn by hand until snug. Don’t over-tighten — a gentle, firm twist is enough. After refilling oil, always double-check the cap is back on, it’s a common pit stop error. If the cap has been off during servicing and there’s a light oil mist around the top of the engine afterwards, re-seat or replace the cap and clean the area. Owners running the MZR petrol engines will typically see a cap marked “Engine Oil” with viscosity info. While different engines used in the Premacy share similar caps, matching the cap to the engine family ensures correct fit and seal.

• Replace the cap if: the O-ring is flattened, there’s visible cracking, it won’t seat squarely, or there’s persistent oil odour near the cam cover.
• Keep a spare O-ring on hand, a fresh seal often cures minor weeps.
• Wipe dust away before removing the cap to avoid debris entering the engine.

FAQs

Where is the oil cap on a 2007 Mazda Premacy?
It sits on the top of the engine’s cam (rocker) cover, under the bonnet, typically central or slightly offset depending on whether it’s the MZR petrol or MZR-CD diesel. It’s a black, round, screw-on cap labelled “Engine Oil”.

What oil cap fits a 2007 Mazda Premacy?
Use a cap specified for the CR-series Premacy/Mazda5 engine fitted to the vehicle (MZR petrol or MZR-CD diesel). A genuine Mazda cap or a reputable OE-equivalent ensures the thread, seal diameter, and heat resistance are correct.

Can a faulty oil cap cause leaks or smells?
Yes. A hardened O-ring or warped cap can allow a light oil mist around the cam cover and a warm oil odour after driving. Replacing the cap or seal typically fixes the issue quickly.