The main reason all of the VANOS units will eventually fail is because the material used for the sealing rings from the factory is not designed for that type of environment. When this happens the only option that BMW leaves you with is buying a new and expensive VANOS unit with the same sealing rings that failed in your original unit.

The VANOS system found in BMW engines is a great feature (when it’s working properly), keeping your power curve smooth and responsive especially in lower to mid RPM range. What usually goes unnoticed is the gradual loss of power within this range as the vehicle's age due to slowly failing seals within the VANOS unit. The way the VANOS system works is based off of oil pressure triggered by a solenoid that allows for a small range of timing degree adjustment, this is where the power curve is affected. When the seals begin to fail (all of them do) there is less pressure to advance the timing reducing the power in that low to mid range. Because this happens slowly it's very hard to notice a difference until you refresh your VANOS unit, then you easily realize the response you've been missing.

There are a number of symptoms that will plague your car as a result of these failing seals such as erratic idle, engine hesitation, stalling, and increased fuel consumption to name a few. If you've been chasing down any of these symptoms with no fix then this could be your issue.

While you're replacing the seals in your VANOS unit it a good time to install anti-rattle spacers to tighten up the gaps in your stock assembly and get rid of that noisy VANOS clatter.

Seals & O-rings:

The seals  were the main focus of this project since the OE units are built with Buna-N rubber o-rings instead of the ECS supplied Viton rubber o-rings. The Buna-N material quickly hardens from the heat and chemical exposure within the engine, where the Viton is significantly more resistant to these chemicals. This knowledge was also used when it came to the commonly failed o-rings found on the VANOS seal plate, replaced at the solenoid.

Rattle Repair:

When it comes to the VANOS rattle this is commonly described as "marbles in a can", and can be heard throughout the different RPM ranges depending on the engine. These upgraded rings and washers are precision ground from hardened steel to resist wear and deformation keeping your VANOS rattle free. The rattle repair tools are designed specifically for this VANOS anti-rattle repair, design from hardened steel to stand up to the job. Designed to perfectly follow the splines of the shaft for a tight grip when applying the necessary torque to disassemble & reassemble the VANOS transfer gear. The keyed socket was designed with the intent to use a "common" wrench so this can be completed at home in your garage.    

When Servicing your VANOS unit we recommend getting everything you need to replace on the way to service which includes an oil change and valve cover gasket set. Fresh oil and gaskets is the best way to start off a fresh rebuild of any kind giving you the maximum performance of your freshly serviced components.

Don't forget to check out our rebuild PDF to make sure you have everything to get the job done and eliminate the rebuild guess work.

This item fits the following BMWs: 
2000-2001 E46 3 Series M3 M3 Convertible 2000-2006 
2001-2002 Z3 Roadster / Coupe Z3 M Roadster Z3 M Coupe w S54 Engine 
2006-2008 E86 E86 Z4 Z4 M Roadster Z4 M Coupe

If you're not sure if your Vanos seals are bad then the only question you need to answer is if you've replaced them. Every unit from the factory came with the same failure prone o-rings and seals, even the re-manufactured units you can still get today. The only real fix is by replacing the seals and o-rings with material that is built to last in the oiled, extreme temperature environment found in these kits. 

A premium product replacement with easy to follow instructions makes rebuilding your Vanos unit a must. Even thought the power loss is barely felt it's the opposite result once you replace the seals, every car that gets rebuilt ends up wowing the customer and all of them saying they didn't realize what they lost. 

There are a number of symptoms that will plague your car as a result of these failing seals such as erratic idle, engine hesitation, stalling, and increased fuel consumption to name a few. If you've been chasing down any of these symptoms with no fix then this could be your issue.

This kit includes all of the sealing needs to get your engine and vanos back into shape. If you're looking to replace the tensioners while you're in there then the Complete Vanos Rebuild Kit is what you need.

This item fits the following BMWs: 
1999-2001  E38 BMW  740i 740il 
1999-2003  E39 BMW  540i 
1999-2003  E53 BMW  X5 4.4i X5 4.6i

If you're not sure if your Vanos seals are bad then the only question you need to answer is if you've replaced them. Every unit from the factory came with the same failure prone o-rings and seals, even the re-manufactured units you can still get today. The only real fix is by replacing the seals and o-rings with material that is built to last in the oiled, extreme temperature environment found in these kits. 

A premium product replacement with easy to follow instructions makes rebuilding your Vanos unit a must. Even thought the power loss is barely felt it's the opposite result once you replace the seals, every car that gets rebuilt ends up wowing the customer and all of them saying they didn't realize what they lost. 

There are a number of symptoms that will plague your car as a result of these failing seals such as erratic idle, engine hesitation, stalling, and increased fuel consumption to name a few. If you've been chasing down any of these symptoms with no fix then this could be your issue.

While you 're replacing the seals in your Vanos unit it a good time to install anti-rattle spacers to tighten up the gaps in your stock assembly and get rid of that noisy Vanos clatter.

Rebuild instructions : http://bd8ba3c866c8cbc330ab-7b26c6f3e01bf511d4da3315c66902d6.r6.cf1.rackcdn.com/PDF_12017_BMW_M5X_Dual_Vanos_Rebuild_Kits.pdf

This item fits the following BMWs: 

1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi 
1999-2003 E39 BMW 525i 528i 530i 
2004-2010 E60 BMW 525i 530i 
2004-2006 E83 BMW X3 2.5i X3 3.0i 
2000-2006 E53 BMW X5 3.0i 
1999-2002 Z3 BMW Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i 
2003-2005 Z4 BMW Z4 2.5i Z4 3.0i