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- Accessories
- Brakes
- Chassis / Bodywork
- Clothing & Gifts
- Electrical & Relays
- Engine Cooling
- Engine Electrical
- Engine Rebuild Parts
- Engine Tuning
- Exhausts
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Porsche
Fits:
Porsche 964 C2 / C4 1989-94
Porsche 964 Carrera RS 3.6L 1992
Porsche 964 C2 Tiptronic 1990-94
Click 'Zoom in' for large parts diagram.
Diagram ref no 9.
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
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Fits:
Porsche 911 1969 - 1977
Porsche 914-6 1970 - 1976
Porsche 924 1976 - 1979
Diagram ref no 6
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90007514803
The product you are viewing cross references to these numbers
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 924 2.0L 1976-79
- Porsche 914 (1970-1976)
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12 Month Warranty
Worldwide Delivery
Heat Exchanger Hexagon Nut – M10
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Ensure a secure and reliable exhaust installation with this Heat Exchanger Hexagon Nut. Manufactured to original equipment specifications, this high-quality
replacement hexagon nut is used to securely fasten the heat exchanger to the
engine's exhaust studs, ensuring a tight, leak-free connection.
Fits:
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Diagram ref no 7
Heat exchanger mounting hardware is continually exposed to extreme exhaust temperatures, moisture, road salt and vibration. Over time, the original nuts can corrode, seize or lose their clamping force, making removal difficult and increasing the risk of exhaust leaks. Replacing worn or damaged hardware whenever the exhaust system is removed is considered best practice for both servicing and restoration work.
Manufactured from durable, corrosion-resistant materials, this OE Match hexagon nut provides dependable clamping force and long service life, making it ideal for routine maintenance, exhaust repairs and concours restorations.
What Does the Heat Exchanger Hexagon Nut Do?
The hexagon nut secures the heat exchanger to the cylinder head via the exhaust studs.
Its primary functions include:
- Securing the heat exchanger firmly in position.
- Maintaining correct gasket compression.
- Preventing exhaust gas leaks.
- Resisting loosening caused by vibration and heat cycling.
- Supporting proper exhaust alignment.
- Helping maintain engine performance and efficiency.
Correctly tightened exhaust hardware is essential for a safe and reliable exhaust system.
Why Should the Heat Exchanger Nut Be Replaced?
Exhaust mounting hardware operates under extremely demanding conditions.
Common reasons for replacement include:
- Corrosion caused by moisture and road salt.
- Heat cycling leading to material fatigue.
- Seized or rounded nuts during removal.
- Damaged threads.
- Reduced clamping force.
- Exhaust system restoration.
- Heat exchanger replacement.
Replacing the hardware during exhaust work helps avoid future maintenance issues and ensures a secure installation.
Symptoms of Worn or Damaged Exhaust Hardware
Typical signs include:
- Rusted or heavily corroded nuts.
- Seized fixings.
- Exhaust leaks.
- Loose heat exchanger.
- Rattling exhaust components.
- Broken or damaged fasteners.
- Difficulty removing existing hardware.
Renewing the mounting hardware helps restore the integrity of the complete exhaust system.
When Should the Heat Exchanger Hexagon Nut Be Replaced?
Replacement is recommended whenever:
- Heat exchangers are removed.
- Exhaust gaskets are replaced.
- Exhaust manifold repairs are carried out.
- Engine rebuilds are performed.
- Restoring a classic Porsche.
- Existing nuts show signs of corrosion or damage.
Installing new hardware during reassembly helps ensure reliable sealing and long-term durability.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99908400202
The product you are viewing cross references to these numbers
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Shop Securely
12 Month Warranty
Worldwide Delivery
Fits:
Porsche 911 1969 - 1977
Porsche 914-6 1970 - 1976
Porsche 924 1976 - 1979
Diagram ref no 6
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90007514803
The product you are viewing cross references to these numbers
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Shop Securely
12 Month Warranty
Worldwide Delivery
Monday-Friday: 8.30am - 5.30pm (GMT)
Saturday: Closed
Sunday: Closed