Valve stem seal replacement on N46 engines

Earlier years, when valve stem seals hardened, the cylinder head was removed in order to replace the seals. This was quite a costly repair. Now, with the correct tools, the seals can be done in place. This is a huge time and cost saver. The classic symptoms on the N46 or N46N engines would be: an increase in oil consumption, as well as seeing white smoke from the exhaust. The smoke is usually visible only after the engine has been idling for a while, and you put your foot on the accelerator. However, with normal driving, there is no smoke from the exhaust.