Double Vanos Rebuild Service (M52TU, M54, M56)
You will be required to send us your DOUBLE VANOS for this rebuild service.
* 1 Year unlimited mile warranty
The VANOS unit is a system devised by BMW that allows for variable timing adjustment while driving under different conditions. It works on the engine’s oil pressure and continuously adjusts as the engine runs.
So, what exactly goes wrong with the VANOS unit? The adjustment mechanism in the vanos has a set of seals that hold the oil pressure and enable the piston that adjusts the cam to function and alter the cam position. The BMW factory installed seals are made of BUNA material and this material is not very resistant to oil and temperature fluctuations. The units are also prone to wear and can develop a rattle if the play isn’t removed from their internal parts. We install ungraded Teflon seals to replace the old worn BUNA seals. We also replace the worn component to eliminate the internal play which causes the rattle.
Is my VANOS unit faulty? The original seals from the BMW factory were good for approximately 20k miles and after that, the seals hardened and lost their ability to function efficiently (if at all). The chances of your unit being faulty are quite likely if your car has any substantial amount of mileage on it. If your car has a vanos rattle, then this will cure that problem, too.
What are the symptoms of a faulty VANOS? The vanos system contributes to a number of factors that control the peak running of your M52TU/M54/M56 motor. Some of these symptoms of failure can include:
- – Increase in fuel consumption
- – Bogging or hesitation under 3,000 RPM
- – Sudden power surge at approximately 3,000 RPM
- – Louder idle / vanos rattle
- – Loss of torque in the lower RPM range
It is important to note that when a vanos has been rebuilt, it is normal for the car to take ~100 city driving miles to properly bleed the vanos after replacement before the optimum results are felt. Also, a change in fuel consumption might not be noticed until at least a week after the replacement as the car takes some time to re-learn and once this occurs only then can the changes be fully recognized.