Stud for Exhaust Manifold - M8x30, L: 45mm - for Porsche 911 Carrera 3.2L 1984-89 & 911 (930) / 964 Turbo 1978-94  ❭  99906223903

Stud - M8 x 30 / 45mm - which is used to mount the heat exchanger.
This exhaust manifold stud is a high-strength threaded stud used to secure the exhaust manifold (heat exchanger) to the cylinder head on classic air-cooled Porsche 911, Turbo (930), and 964 Turbo models.
Sold individually, 12 required per engine. 

Fits:
Porsche 911 Turbo (930) 1978 - 1989
Porsche 911 Carrera 3.2L 1984 - 1989
Porsche 964 Turbo 3.3L 1991 - 1992
Porsche 964 Turbo 3.6L 1993 - 1994

Diagram ref. no. 5A

The exhaust manifold stud forms a critical fastening point that holds the exhaust manifold (or heat exchanger) firmly to the engine’s cylinder head. It ensures the exhaust system components remain tightly seated under heat, vibration, and thermal cycling, preventing exhaust leaks and preserving engine performance.

This stud’s threaded design enables secure engagement with corresponding nuts and manifold flanges. By maintaining proper clamping force, it helps support the manifold gasket and metal mating surfaces, sustaining a leak-free joint under extreme exhaust temperatures and repeated heating/cooling cycles.

Exhaust studs undergo intense heat and stress, which over time can lead to stretching, thread wear, or breakage. A compromised stud can allow exhaust leaks, reduce engine efficiency, and make future removal of the manifold difficult. Replacing them restores correct fit, proper torque retention, and long-term exhaust system reliability.

When to replace:
•  Studs show corrosion, thread wear, or distortion
•  One or more studs have broken during removal
•  Exhaust leak noises at the manifold flange
•  During manifold gasket replacement
•  Preventive renewal during engine or exhaust overhaul

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