Cooling system modification Audi AGU and E-gas 1.8T 20V engines

Every Donkervoort equipped with an Audi 1.8 T 20V engine has a cooling system connection, which statistically causes a faulty full drain of the cooling system. This of course always happens on a long enjoyable trip or on a beautiful evening spin. Make your car reliable with the following modification.

Standard situation

This standard reinforced plastic Audi cooling system part (part number 06A_132AP) is modified by Donkervoort. A nipple is glued with an Araldite equivalent glue into the plastic part. As a result of vibrations and temperature changes, the nipple frequently starts to leak over the years or the nipple just pops out loosing all high temp coolant. The location in the car, and the fact that new glue needs to harden before use makes it fairly difficult to do it as a roadside repair. Do don’t want that to happen and fresh coolant all over your new Donkervoort driving shoes!


  • The black Bosch or aluminium FORGE blow-off valve and the air intake manifold piece / or rubber intake hose between the air mass meter and the turbo air intake.
  • Drain your cooling system partly at your radiator.
  • Remove the faulty black cooling system part next to the Air Pump EGR Check Valve Assembly / pressure control valve for crankcase breather.


Modification option 1, preferred

Several Audi tuners on the internet offer a more durable cast aluminium alternative to for the OEM #number. This part comes with an upgraded brown silicone seal instead of the less durable black rubber o-ring. In addition source an aluminium made weld hose nipple of the correct diameter. Take all your bits and pieces to a company which masters the art of cast aluminium welding. They are able to modify the cast aluminum body exactly to Donkervoorts original, but in a durable version. Remount all your parts and refill your cooling system with the required coolant.



If you master aluminium hard brazing/ soldering with the aid of a simple Propane torch, you can do the whole job yourself with HTS-2000. This works without Flux. Easy! Als great for repairing aluminium radiators. First test it on other equivalent material. Keep road assist service away. Happy driving!



Modification option 2, alternative as enthusiastically developed and shared by a fellow Donkervoort driver

Manufacture a bracket from 1,0 or 1,5 mm stainless steel plate material according to the following drawing. Click to enlarge. Bend the 2 bracket ears in an angle of 90 degrees, and mount with a neoprene rubber o-ring and a stainless steel hose clamp as shown in the images below.