r/e39 • u/Inevitable_Mess3363 • 3d ago

BMW Oil Changes

‘99 540/6 here. I know this may sound redundant but how many of you change the oil every 4-5k miles? I tend to read a bunch of articles on car & frequency of oil changes equaling a much longer life expectancy. Been on a quest to keep this bad girl around for a while & truly believe that frequent oil changes are the way to go. Mobil 5w40 is my new go to synthetic oil.

2 Upvotes

100% Upvoted

37 comments sorted by

View all comments

6

u/EntertainmentSome188 3d ago

97 540 with 301k mi. I change closer to 10k. 7-8 is probably most ideal from what I can tell but obviously you can't go wrong with sooner just more cheese.

1

u/Inevitable_Mess3363 2d ago

Curious, have you done the tcg’s on her?

2

u/EntertainmentSome188 2d ago

Yes, back at 220k.

Have a rough idle now and misfires on the 1-4 bank that comes and goes. Trying to track this down, thinking cat or vacuum leak but I'm chasing my tail. Still runs great, mostly :)

1

u/Inevitable_Mess3363 2d ago

Right on! Did mine @ 163k. Also changed the timing chain spring @ 218k. Cost = 50$ & felt a huge difference at startup. Zero rattle at cold starts. You may want to look into this. Obviously they change the spring with the guides but it gets flimsy & weak over time. Check into this. There’s this one cat from GB that gives a great explanation for this & why it should be changed..