Genuine Mazda Upper Intake Manifold / Surge Tank Gasket – 1.8 VVT • BP6Z-13-135

Genuine Mazda BP6Z-13-135 Upper Intake Manifold / Surge Tank Gasket

Replacement Genuine Mazda upper intake manifold gasket for Mazda MX-5 Mk2.5 NB-FL models fitted with the 1.8-litre VVT petrol engine.

Mazda describes the upper section of the intake manifold as the surge tank or plenum chamber. This gasket seals the joint between the upper surge tank and the lower section of the flat-top intake manifold.

An airtight seal at this joint is essential for maintaining stable manifold vacuum and preventing unmetered air from entering the engine. The original gasket can become compressed, hardened or damaged with age or during intake-manifold dismantling.

One gasket is fitted per vehicle, and this listing supplies one Genuine Mazda gasket. It should be replaced whenever the two sections of the intake manifold are separated.

Important fitment restriction: BP6Z-13-135 is intended for the flat-top intake manifold fitted to 1.8 VVT Mk2.5 NB-FL models. Earlier Mk2 NB vehicles use a different surge-tank gasket. This listing does not automatically cover turbocharged models or vehicles fitted with an alternative intake manifold.

• Part type: Upper intake manifold gasket
• Common names: Surge-tank gasket / plenum gasket / flat-top manifold gasket
• Mazda catalogue description: Gasket, Surge Tank
• Location: Between the upper and lower sections of the intake manifold
• Intake manifold type: European / Japanese-market flat-top manifold
• Engine application: 1.8-litre VVT petrol engine
• Primary engine code: BP-Z3
• Function: Seals the surge-tank joint against vacuum and air leakage
• Quantity fitted per vehicle: 1
• Quantity supplied: 1 gasket
• Reusable component: No
• Upper intake manifold included: No
• Lower intake manifold included: No
• Throttle-body gasket included: No
• Manifold-to-cylinder-head gasket included: No
• Sealant included: No
• Brand: Genuine Mazda
• Part No.: BP6Z-13-135
• MX-5 fitment: Mk2.5 NB-FL 1.8 VVT models

Possible signs of an intake-manifold gasket leak:

• High, unstable or uneven idle speed
• Hesitation or poor low-speed response
• Lean-running fault codes
• Misfire, particularly at idle
• Whistling or hissing from the intake manifold
• Reduced engine performance
• Vacuum leakage around the surge-tank joint
• Gasket visibly compressed, split or damaged after dismantling

Fitment advice: Confirm that the vehicle has the 1.8-litre VVT engine and the original flat-top intake manifold before ordering. Earlier Mk2 models and vehicles fitted with alternative intake arrangements require different components.

Replacement advice: Replace the gasket whenever the upper surge tank is separated from the lower manifold. Reusing the compressed original gasket may result in an intake-air leak even where no obvious damage is visible.

Other items to consider: Inspect the throttle-body gasket, manifold-to-cylinder-head gasket, vacuum hoses, PCV hoses, injector seals and any air or coolant hoses disturbed during dismantling. Consider purchasing replacement hose clamps where the originals are weakened or corroded.

Useful tools / consumables: Socket and spanner set, calibrated torque wrench, hose-clamp pliers, plastic gasket scraper, lint-free cleaning materials and suitable intake-system cleaner.

Difficulty guide: DIY Difficulty: Moderate. Replacement requires removal of the upper surge tank and careful disconnection of the associated vacuum hoses, wiring and intake fittings.

Why Genuine Mazda? Genuine Mazda intake gaskets match the original port profile, fastener alignment, compressed thickness and sealing design. Correct dimensions help maintain stable manifold vacuum and prevent unmetered air entering the engine.

What’s in the box: One Genuine Mazda upper intake manifold / surge-tank gasket, part number BP6Z-13-135.

Installation notes: Allow the engine to cool before dismantling the intake system. Label and disconnect the required intake hoses, electrical connectors and vacuum lines. Remove the upper surge tank following the applicable Mazda procedure. Remove the old gasket and clean both mating surfaces without scratching them or allowing debris into the open intake runners. Position the replacement gasket correctly, refit the surge tank and tighten the fasteners progressively to the applicable Mazda specification. Reconnect every hose and connector, then start the engine and check for stable idle and intake-air leaks.