Rein CTI0004 Engine Coolant Thermostat

OE Thermostat Insert for Volkswagen and Audi

Rein CTI0004 is an OE quality engine coolant thermostat insert built for direct replacement service on select Volkswagen and Audi applications. It is calibrated to open at 71 degrees Celsius to help maintain the engine’s operating temperature within the intended range.

For drivers and technicians servicing a Volkswagen Beetle, Golf, Jetta, Passat, Cabrio, Cabriolet, Fox, Corrado, Quantum, or select Audi 80, 90, and 4000 models, this thermostat insert is designed around original equipment specifications for a straightforward repair.

Key Features

• Matches original equipment design specifications
• Thermostat set to 71 degrees Celsius for stable coolant control
• Manufactured to strict engineering standards for materials and tolerances
• High-quality metal and component construction for durability
• Gaskets or seals needed for installation are supplied with the thermostat
• Direct replacement thermostat insert for OE-style service

Detailed Description

Rein CTI0004 is an engine coolant thermostat insert engineered as a direct OE replacement for a wide range of Volkswagen and Audi vehicles. Rein builds these thermostat inserts with temperature calibration and material selection aimed at consistent response in the cooling system, helping the engine reach and maintain proper operating temperature. The part number CTI0004 is also referenced in OE-style replacement searches for 044121113 and 056121113D applications.

This thermostat insert is a practical choice for Volkswagen Beetle, Golf, Jetta, and Passat cooling system repairs, as well as older Volkswagen Cabrio, Cabriolet, Fox, Corrado, and Quantum models. It also serves select Audi 80, Audi 90, and Audi 4000 applications where a 71C thermostat is specified.

Common Problems This Part Can Address

• Engine running cooler or warmer than specified
• Slow warm-up after cold starts
• Temperature fluctuation caused by a worn thermostat
• Cooling system service on a Volkswagen or Audi with OE-style thermostat requirements
• Replacement of a thermostat insert that no longer regulates coolant flow correctly

Installation Notes and Tips

Verify the thermostat temperature rating and housing style before installation. This part is application specific, so confirm the vehicle listing and cooling system configuration for your Volkswagen or Audi model before ordering. Clean the sealing surfaces thoroughly and inspect the housing for wear or damage during service.

All gaskets or seals necessary for installation are supplied with the thermostat. Follow the vehicle manufacturer’s cooling system service procedure, refill with the correct coolant, and bleed air from the system after installation.

Quality Assurance

Rein OE quality thermostat inserts are manufactured to meet or exceed OE material expectations and are temperature calibrated for consistent operation. The brand’s focus on direct-fit cooling system components supports reliable service life and OE-style performance in routine maintenance and repair.