do not press the back button…
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
Heat Exchangers
By OE Match
- 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)
Heat Exchanger Hexagon Nut – M10
Sold each
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)
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
OEMatch Heat Exchangers — Fit, Function, Confidence
Heat exchangers recover heat from exhaust gases to supply cabin heating and assist thermal management. For Porsche models they help maintain warm-up behaviour and exhaust routing while limiting fumes reaching the cabin. OEMatch supplies replacements selected for these applications.
Available Types
- Exhaust-to-air heat exchangers in stainless or aluminised steel for air-cooled engines
- Heater cores and heater boxes for cabin heating in classic and modern Porsche models
Understanding OEMatch Heat Exchangers
OEM (Original Equipment Manufacturer) parts are made by the same company that produced your Porsche’s original heat exchangers.
OE (Original Equipment) refers to parts matching original specifications for the heat exchangers and may be supplied by alternative manufacturers. Aftermarket parts offer alternative options, sometimes with enhanced features or better value. OEMatch supplies non-OEM heat exchangers engineered as direct-fit alternatives to OEM parts, made to original-spec dimensions and tolerances for Porsche models. Heat exchangers capture waste heat from exhaust gases and direct it to the heating system or auxiliary circuits; they help preserve engine temperature, reduce warm-up time and support safe cabin ventilation when intact.
Benefits Include
- Restores cabin heating and occupant comfort in air-cooled applications
- Reduces the risk of exhaust gases entering the vehicle cabin
- Improves exhaust routing and thermal efficiency during warm-up
Why Heat Exchangers Wear and Fail
- Corrosion and perforation from condensation and road salt
- Cracks or fatigue from repeated thermal cycling or impact
- Carbon and soot buildup restricting heat transfer and flow
The Importance of Replacing with OEMatch Heat Exchangers
Replacing a worn or leaking heat exchanger preserves cabin heating, prevents exhaust contamination and helps maintain correct exhaust back pressure for engine performance. OEMatch catalogues thousands of Porsche part numbers and cross-references to support repairs and restorations; products are selected to suit classic and modern Porsche applications.
Advantages
- Corrosion-resistant materials such as stainless or aluminised steel
- Formed components that match expected mounting and routing for Porsche models
- Suitable for restoration, maintenance and model-specific repairs
