The VANOS unit used in BMW's allows for a timing advancement at lower RPM's that creates a more linear power curve giving your vehicle more low end torque. While driving the VANOS system is constantly varying the position of the camshafts depending on what gear you're in to improve idle, torque, fuel consumption, and emissions. When the seals within your VANOS system fail they allow much needed pressure used to activate the advancement to slip by slowly getting worse in time. This is the reason many owners never really notice a difference in performance until they complete the rebuild and restore the lost power. If your car has more than 80,000 miles on it chances are good you have performance lost from a failed VANOS if you haven't replaced your seals already.
When it comes to VANOS failure it's never a matter of it it will fail, it always comes down to when. The seals that were installed from the factory were made from a material called Buna which is not acceptable for the chemicals found in oil and the high temperatures. The o-rings used in our ECS kits a made from Viton, the proper material used in these conditions as well as teflon seals to rebuild these units the way they should have been from the factory. By upgrading to the materials used in our in-house engineered kits your VANOS will by far outlast the life expectancy of an OEM unit.
If you haven't purchased the VANOS tool to properly rebuild your unit be sure to get one before you check out, the press tool is required for proper rebuild.
Failure symptoms:
