The Volkwagen Auto Group (VAG) designed the Passat as a midsize sedan platform in Europe, though it qualifies as a small car in the North American market. The Passat platform is also used by Audi for their A4 sedan and station wagon. Some Passat cars are offered with turbocharged engines that boost the air pressure in the combustion chambers, leading to more power. However turbochargers need blowoff valves to prevent that overpressure from blowing back into the turbocharger and damaging the turbine blades. If the valve malfunctions, then it needs to be replaced immediately or the overpressure can damage the turbocharger and engine.
Things You'll Need
- Screwdriver set set
- Drop cloths
Park the Passat in your driveway and pull the emergency brake up. Pull the hood release latch, then turn the Passat off. Prop the hood up and disconnect the black cable from the car battery to protect yourself from electrical shorts. Put drop cloths on the edges of the engine bay to protect the paint.
Locate the turbocharger downpipe; the Passat's blow off valve is attached to the side of the pipe. Pull the vacuum line top from the top of the blow off valve by hand. Unscrew the O-ring clamp that secures the bottom of the valve to the downpipe port. Pull the old blow off valve off and place it to the side.
Plug the new blow off valve into the port on the downpipe. Screw the O-ring clamp onto the bottom of the blow off valve until it is tight and will not budge. Plug the vacuum line in on the top of the blow off valve. Reconnect the black wire to the car battery and shut the Passat's hood.
Turn the Passat on and take it for a test drive. If the Passat blow off valve is installed correctly, the engine speed will drop suddenly once you exit the turbo power band. If the engine speed stays elevated after fast driving, then the blow off valve is not working right. The vacuum line may have come off or the blow off valve spring may be broken.
- "Haynes: VW Passat (1998 through 2005) and Audi A4 (1996 through 2001) 1.8L 4-cylinder turbo and 2.8L V6 engines"; Haynes Publishing; 2008
How to Replace Valve Cover Gasket in a VW Passat
Your Volkswagen Passat will function badly--and eventually not at all--if it has an oil leak. To avoid problems, you can remedy the...
How to Install Blow Off Valves
A blow off valve is a device that allows recirculating air to exit the intake/exhaust system on a turbocharged vehicle. Without the...
How to Install Speakers on an Audi A4
Do you love everything about your Audio A4 except for the sound from the stereo system? If your speakers pop, buzz or...
How to Adjust a Turbo XS Blow Off Valve
A Blow Off valve, or BOV, is a component found in most turbocharged engines. It is used to release compressed air from...
How to Install a SRT-4 Blow Off Valve
People install aftermarket blow off valves on their turbocharged SRT-4's for multiple reasons. It may simply be because you want a cooler...
How to Install an HKS Blow Off Valve
HKS manufactures various aftermarket blow-off valve kits that bolt easily onto your turbo system's aftermarket intercooler piping. The HKS blow-off valve will...