[kevinb21]

2013 bmw 328i Sulev, n26 engine. About 93,000 miles. Driven somewhat aggressive, oil changed with Castrol full synthetic 0w-40 oil every 6k miles, with oem bmw filters, nothing else has been done other than recalls and brake fluid/pads.

I recently replaced all 4 spark plugs with oem bmw plugs and it's running noticeably smoother, I plan on continuing the maintainence before the car hits 100k since I will keep this car forever

Do I need to replace just the timing chain and guide/ tensioner or do I also have to change the oil pump and other stuff since the price difference in the kits are insane

Also what is needed for a transmission and differential service,

Lastly the car sometimes smells like burnt oil from the engine but I can not find any leaks, it's bone dry. Also the auto start stop has a noticeable squeak right before the engine shuts off.

Details on what should be done at this mileage would be well appreciated! (Do I need serpentine belt? Valve cover? Trans fluid? Coolant flush? Timing chain? Pcv valve?)

Thanks!