Differences Between 058 and 06A VW Blocks

There are a lot of subtle differences between the 058 and 06A VW blocks although what isn’t different is how versatile their use was for Volkswagen. Both blocks were used with variety of different internals, cylinder heads, and even were used for both gas and diesel configurations.

The most noticeable difference between the 058 and 06A VW Block is that the 06A block had an internal water pump that was ran off the timing belt, instead of the external water pump setup that they had used from 1974-98 on their 4cyl engines.

Here are some other differences:

• 058 blocks have an internal intermediate shaft that that drives the oil pump and use an external water pump driven by an accessory belt.

• 058 blocks are only found in the early longitudinal Audi B5 A4 and VW B5 Passat.

• 06A blocks do not have an intermediate shaft and use a water pump driven by the timing belt. The oil pump is chain driven by the oil pump drive gear located on the snout of the crankshaft.

• 06A blocks use a slotted style trigger wheel.

• 058 blocks use a dented style trigger wheel.

• Most 06A 1.8T engines employ a 19mm wrist pin (225 horsepower models use 20mm).

• 058 1.8T engines typically use a 20mm wrist pin.

• 058 Use 11mm head bolts.

• O6A use 10mm head bolts

Cylinder Head

Although numerous cylinder head configurations were used globally, domestically the 058 came with the AHU/1Z Diesel 8v and the 1.8T AEB 20v. The Diesel only came in the 97-98 MK3 Jetta and 96-97 B4 Passat’s. The 20V Only came in longitudinal configurations stateside, specifically B5 Chassis Passat’s and Audi A4’s.

The Diesel 8v head would be hard to distinguish from previous generation diesel heads if you didn’t know what you were looking for. The 20v on the other hand was much more exciting. Similar to the excitement of the 16v’s release in the 80’s. The 20v head was based off the Yamaha designed 5v setup, seen here:

VW/Audi 5-Valve Head:

The 20v head was used on both 058 and 06a blocks and ranged in production from 1998-2005. All domestic iterations came with turbos. Most setups sported a Borg Warner K03, some special models (337, 20^th AE, TT225) Came with the larger K03s or K04.

The cylinder heads that came on the 058 are desirable to the enthusiast and performance builders alike, as they had larger intake ports, which allowed a lot better airflow.

When you are in need of expert Volkswagen repair or performance tuning give Alex’s Autohaus a call at (801) 566-6115 and we would love to help you get the most out of your vehicle.