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Block Coolant Adapter, Rear Audi I5 20v, Late (25mm)


We're pleased to offer an improved, billet aluminum block coolant adapter for virtually all Late Audi I5 20V blocks! The block coolant adapter feeds coolant out of the back of the block to the heater core system, and can disintegrate over time from the heat seen in your engine bay. Our improved, CNC-machined piece ensures you will never need to replace this again, and includes a new bolt and o-ring seal. 

This replaces later (AAN, ABY, ADU, all made from plastic) 25mm coolant adapters!

If you have an early 22mm (Pre ~ 1990 made from Metal) coolant adapter, please order our Block Coolant Adapter, Rear Audi I5 20V, Early (22mm).

Please Note: Due to the age of most blocks, we recommend a light coating of RTV on the o-ring before installation to seal up any pitting or uneveness in the block sealing surface.

For proper installation, ensure all rust and remains of the old o-ring and housing are cleaned out of block or else the new unit will not fit.  These are tested and validated on a good, rust free block. If you are having issues fitting this housing, clean out the block port area until it fits properly.  The fitment of this part is the exact same as a new OEM unit.

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