Ford RS MK3 PTU Cooling System
The Ford Focus RS Mk3 is a highly popular and well-regarded sports car, but like all high-performance vehicles, it has its weak points. One of the main issues arises during intense driving, particularly on track days and high-performance driving events, where the drivetrain components tend to overheat. A common issue is the appearance of an AWD system failure warning, followed by the disconnection of the rear differential, which can be extremely frustrating for the driver.
The root cause of this problem is the overheating of the Power Transfer Unit (PTU) due to insufficient cooling. When the PTU overheats, the car’s ECU disables the rear-wheel drive to reduce strain on the PTU and allow it to cool down.
The Ultimate Solution
After years of extensive testing, we are proud to introduce a unique PTU cooling system—the only one of its kind, delivering exactly what Ford Focus RS Mk3 owners have been waiting for.
Key Features of the Ford RS MK3 PTU Cooling System:
✔ OEM Engine Cooling PTU Heat Exchanger – Seamless integration with the factory cooling system
✔ Standalone Water Pump – Ensures continuous and efficient coolant circulation
✔ High-Performance Radiator – Effectively lowers the PTU’s operating temperature
✔ Coolant Reservoir – Provides sufficient capacity for consistent cooling performance
✔ Precision-Matched and Durable Coolant Piping – Designed for long-lasting reliability
✔ Electric Installation with ON/OFF Switch – Allows complete manual control over the cooling system
✔ Wiring Relocation Kit – Creates space for the new installation
✔ Professional-Grade Mounting Components – Ensures system stability
The pump automatically starts and stops with the engine, and an additional switch allows full control over the system, enabling drivers to turn it off during cold weather or low-intensity driving.
By ensuring optimal cooling for your Ford Focus RS Mk3, you can enjoy worry-free driving, even under the harshest conditions. This is a solution that many companies, including Mishimoto, have attempted to create but have yet to develop a complete package.
Key Facts About the Ford Focus RS Mk3 AWD System
The AWD system of the Ford Focus RS Mk3 consists of two main components:
🔹 Power Transfer Unit (PTU) – Located at the front
🔹 Rear Drive Unit (RDU) – Located at the rear
The most common reason for AWD system failure is overheating of the PTU or RDU. During intensive track driving, the PTU typically overheats first, causing the ECU to disengage the rear differential to reduce strain on the system.
Repeated testing has also shown that the RDU tends to overheat during aggressive drifting, donut sessions, or gymkhana-style driving. Interestingly, the RDU does not have a dedicated temperature sensor; instead, the ECU calculates a virtual oil temperature based on various factors such as:
🔹 PTU temperature
🔹 Steering angle
🔹 G-force readings
🔹 Throttle and brake inputs
🔹 Wheel slip data
During tests, a temperature sensor was installed in the RDU, confirming that the ECU’s calculated oil temperature is highly accurate.
Who Needs a PTU Cooler?
If you want to significantly extend the AWD system’s durability during high-performance driving, an active PTU cooling system is essential.
However, if your goal is drifting or gymkhana-style driving, a more comprehensive solution is recommended, including:
✔ An active RDU cooling system
✔ Software modifications for the RDU (programming adjustments)
Installation Process:
✔ Remove the front bumper
✔ Remove underbody panels and engine splash guards
✔ Remove the left headlight
✔ Disconnect coolant hoses between the engine and PTU
✔ Seal off the engine coolant circuit leading to the PTU
✔ Install the water pump, coolant reservoir, and radiator
✔ Connect all components with coolant hoses
✔ Wire and install electrical components
✔ Optional: Relocate the ON/OFF switch
Maximize Your Driving Potential
If you truly want to use your Ford Focus RS Mk3 for its intended purpose, don’t let overheating ruin your experience. Upgrade with the PTU cooling system today and enjoy uninterrupted AWD performance!