Description
If your OEM bypass valve is in good condition, you have the option of this cheaper part to delete the shaft/valve/vacuum actuator assembly and seal it with this $40 alternative.
(Replaces OEM P/N 059121737AM or 059121737R)
Machined in the USA from 6061 billet with a dished face for smooth coolant flow.
Designed to use Stock Seal which is included (OEM P/N 059121149B).
Includes replacement Gates Hose cut to exact length to mate with Intermediate flange.
This replaces the is the plastic, leak-prone EGR coolant bypass valve in Gen2 3.0 TDI engines.
The hose barb is quite thin, and it it is prone to cracking in higher-mileage cars since its nestled between the HPFP and oil cooler in the valley.
The OEM vacuum controlled valve is part of a divorced coolant loop concept that seperates engine block and cylinder head cooling pathways for the 2nd gen engines.
This oem stock enables almost stagnant coolant in the cylinder block in some scenarios so that the coolant temperature in the cylinder block loop is ~10C higher than the 90C thermostat temperature as it can almost completely close and prevent any flow.
The reason VW included this component in the system is for “emissions reduction” presumably through allowing oil to run even hotter/thinner, likely on piston rings since this is where the coolant temp affects oil temp.
When removing this valve, the coolant loop will no longer be divorced and the cylinder head will run slightly cooler as the regulation is now coming from the primary 90C thermostat (in Gen2 its an assembly with the oil filter housing.
Will you notice any difference of any kind? No.
Note that this piece has no impact on warmup time at all. the valve is 100% open until the car is up to temp.
Install guide in progress:
Relevant Except from Service Manual
Country of Origin:
- Billet Flange: United States
- Seal: Czech Republic
- Hose: United States
- Hose Clamps: United States or Germany
- Vacuum Caps: China
