Euro 4 4JJ1 / 4JJ3 Aluminium Rocker Cover - HPD

The HPD Special Parts cast aluminium rocker cover is the signature engine bay upgrade for Euro 4 4JJ1 and 4JJ3 platforms. Sourced directly from Thailand in small production runs, each cover is finished in a durable painted coating for a clean OEM+ presentation that sets a build apart the moment the bonnet lifts.

Pairs perfectly with other HPD hardware for a fully dressed engine bay — and with the upgraded breather spec on current stock, it's ready for a proper catch can setup straight out of the box.

• HPD cast aluminium rocker cover — painted finish, with 2 additional breather ports
• Screw-in -10 AN fittings for the additional ports
• Bung for the factory breather port
• Genuine HPD breather cover

Bolts are not included. Grab a Ti burnt blue rocker cover bolt set to complete the install.

Suits rocker covers with 4 bolts across the front edge:

• Isuzu D-MAX / MU-X — Euro 4 4JJ1
• Isuzu D-MAX / MU-X — 4JJ3 (2020 on)
• Mazda BT-50 — 4JJ3 (2020 on)

Not sure which cover you're running? Send us your VIN or rego and we'll confirm fitment before you order.

• ✅ Cast aluminium construction — lightweight, rigid and built to last
• ✅ Premium painted finish — genuine Thai OEM+ styling
• ✅ Twin additional breather ports with screw-in -10 AN fittings (current stock)
• ✅ Factory port bung + HPD breather cover included
• ✅ Direct bolt-on replacement for the factory cover

• 💸 Buy Now, Pay Later: Afterpay, Humm, Klarna & Zip available
• ✈️ Free Express Shipping Australia-Wide

These covers are produced in very limited runs and are difficult to source in Thailand. Once a colour sells out, restock lead times typically run 1–3+ months.

Need one urgently? Message us before ordering to confirm availability and the latest ETA.

Q: Do the covers come with breather fittings?

A: Yes — all current stock has 2 additional breather ports machined into the cover, with screw-in -10 AN fittings included, plus a bung for the factory port and an HPD breather cover.

Q: Are bolts included?

A: No — bolts are not included. We stock a matching Ti burnt blue 4JJ1/4JJ3 rocker cover bolt set to complete the install.

Q: How do I know if this fits my engine?

A: This suits Euro 4 4JJ1 and all 4JJ3 engines with 4 bolts across the front edge of the rocker cover. If unsure, send us your VIN or rego and we'll confirm.

Q: Will this fit a pre-Euro 4 4JJ1?

A: This cover is specifically for Euro 4 4JJ1 (4 front bolts) and all 4JJ3 engines. Earlier 4JJ1 models use a different bolt pattern — check out our Euro 2/3 covers instead.

Q: When will sold-out colours be restocked?

A: Aluminium covers are very hard to source in Thailand. Restock times vary but typically run 1–3 months. Contact us for the latest ETA on your colour.