Hello, I drive a BMW E63 630i with the N52 engine, currently it has 177,000 km on the clock. For some time I have to refill cooling water regularly. I also have the following problem: If the car is standing longer than a day, it starts badly and takes about a minute until it runs round. He smokes out of the exhaust, which only happens after the first ride after longer service life. As soon as the engine then runs, everything is fine, and also at the parking place n and restarting there is no problem – no smoke, everything is running smoothly. Has any of you ever had the same problem and could fix it? What was done with you? I am grateful for every tip! Thanks in advance for your help! suspected on cylinder head seal usual with these motors ?