‘ The improvements made to VANOS units by aftermarket companies have significantly improved the durability of the system’
Even a brand new VANOS unit would benefit from a rebuild with modern upgraded parts
‘ The improvements made to VANOS units by aftermarket companies have significantly improved the durability of the system’
US-based Beisan Systems also manufactures uprated solenoid coil pack units, new oil pump hubs and rattle repair kits comprising new bearing rings that significantly reduce play. These would stop any rattles on new VANOS systems and, by reducing small movements, avoid rattles becoming a future problem.
The worn holes in the oil pump disc can be rectified by re-drilling the disc. The hub is located via just two holes, so two new ones can be drilled at 90 ° from the originals – so at East / West when the standard holes stay at North / South. Holes should be re-drilled to reduce play between the disc and hub.
The ultimate solution was created by BMW. It essentially fixed all these problems with its later VANOS systems that used a phaser-style advance on the cam and superseded the splined shaft method. BMW Motorsport began using the newer VANOS on the S65 and, in general, N onwards engines for non-Motorsport engines. Rather than using splined shafts to act upon the relationship between camshaft and sprocket, this newer type is contained within the sprocket itself. It simply has chambers for engine oil, which, as they fill via a channel within the camshaft and are controlled via a solenoid, the sprocket is rotated around the camshaft to advance the timing. It is then returned with an integrated spring. This is a far simpler system and is one that can be found on most modern petrol engines. The solenoids are generally found in the front cover of the engine, so replacement is simple should an electrical issue arise. Mechanically, these are extremely reliable.
How long is the fix likely to last?
Routine maintenance with frequent quality oil changes and regular replacement of VANOS seals, which BMW recommends be changed every 50,000 miles, will help the units last longer than if they are neglected. Just like any engine component. However, a rebuilt VANOS unit using all of the current upgraded parts and techniques can significantly outlast that of a factory-standard unit. The improvements that have been made to VANOS systems by aftermarket companies like Hack Engineering and Beisan Systems are so significant in improving the durability of the system that even non-faulty, very low mileage units would benefit from a modern-style rebuild.
64 The Engine Rebuilder Issue 01