Porsche Low Temperature Thermostat Replacement

Protect your engine. Improve temperature stability. Reduce long-term risk.

At RPM Specialist Cars, we offer a proven, cost-effective upgrade for owners of water-cooled Porsches built up to and including the 2008 model year—including the Porsche 996, 997, Boxster, and Cayman.

Following recent independent studies into early Porsche cooling systems, replacing the factory thermostat with a low-temperature unit has been shown to significantly improve cooling efficiency, reduce engine temperature variation, and help protect against known issues such as cylinder bore scoring.

Why Consider a Low Temperature Thermostat?

Standard water-cooled Porsche engines use a thermostat that begins to open at 83°C. However, data shows this results in an uneven temperature distribution across the engine:

• Cylinder Bank 1 typically runs at 93°C

• Cylinder Bank 2 (thrust side) often reaches 98°C

This 5°C differential can contribute to localised overheating or “hot spots” which over time may increase the risk of engine damage.

By comparison, a low temperature thermostat begins to open at just 71°C. When fitted:

• Overall engine temps are reduced to around 83.8–85.4°C

• Cylinder bank variation is reduced to just 1.6°C

• Engine oil temperature also runs approximately 10°C cooler

These improvements create a more balanced thermal environment within the engine, which helps to reduce wear and stress over time—particularly on vulnerable areas like the cylinder liners.

Preventative Maintenance That Makes a Difference

With the well-documented risk of bore scoring in early Porsche engines, particularly in the 996 and early 997 generation models, we believe this simple upgrade offers real peace of mind.

For just £265.00 (including VAT), we will:

• Replace your factory thermostat with a new 71°C low temp unit

• Refill and bleed the cooling system with fresh Porsche-approved coolant

• Conduct a post-fitment check to ensure your system is operating efficiently

This service not only improves thermal performance but also aligns with the best practices recommended by Porsche specialists worldwide.

Is This Upgrade Right for Your Porsche?

This modification is recommended for:

• Porsche 996 (all models)

• Porsche 997 (2005–2008)

• Porsche Boxster (986 and early 987)

• Porsche Cayman (up to 2008)

If your car is fitted with its original thermostat and has not yet had this upgrade, now is the ideal time to consider it—especially if you’re planning other cooling system maintenance or engine work.