[negendahl]

Hi,

I recently got my 320D F31 from 10/2015, its driven around 140.000km, the dealer where I bought it, changed air, oil and cabin filter + changed engine oil, brake fluid and so on - they also changed the rear brake discs and pads.

Next week I'm booked in at the BMW service for a transmission fluid flush and change (almost 1000 USD ), but I'm wondering what else should be changed soon to ensure stable and proper driving experience?

I read a lot about diff oil, of course spark plugs (don't think they have been changed) - can someone give a little advice on what should be looked at soon?

Thanks!

[negendahl]

Just talked to BMW Service, the same shop doing my transmission fluid change - they said the diff oil is not necessary to change, its lifetime - they only change on M diff's - but i read different in here Anyone to confirm?

[mmm-five]

I've read conflicting views.

Most say change it every 80,000km / 50,000 miles and keep to that schedule (BMW won't do auto trans servicing as they think it's 'lifetime' sealed).

Some say simply do the service as soon as you get the car, no matter what mileage is on it, and then follow the 80,000km interval.

Others say if it's got over 160,000km / 100,000 miles then leave it alone, as you may cause more damage by disturbing what's in there.

My other car, a 330D touring) unfortunately fell into the latter category. Got it at 120,000 miles and did a full service (engine/diff/auto oils, inspection and coolant system refresh), and 4,000 miles later the gearbox failed and required a rebuild...I sold the car and bought a younger model instead.

[negendahl]

You're referring to the transmission fluid change, correct?

I asked the nearest BMW service, they suggested a transmission fluid flush (with a machine) and of course all filters ect. It's booked in officially so I hope it's okay to do 😕

What about the diff oil?

Sucks with your 330D, kind of horror stuff😱

Thanks!

Originally Posted by mmm-five

I've read conflicting views.

Most say change it every 80,000km / 50,000 miles and keep to that schedule (BMW won't do auto trans servicing as they think it's 'lifetime' sealed).

Some say simply do the service as soon as you get the car, no matter what mileage is on it, and then follow the 80,000km interval.

Others say if it's got over 160,000km / 100,000 miles then leave it alone, as you may cause more damage by disturbing what's in there.

My other car, a 330D touring) unfortunately fell into the latter category. Got it at 120,000 miles and did a full service (engine/diff/auto oils, inspection and coolant system refresh), and 4,000 miles later the gearbox failed and required a rebuild...I sold the car and bought a younger model instead.

[auburnf30x]

That BMW claims the differential fluid is lifetime is correct...but I believe they should be changed out every 60k miles/100k km. I have absolutely nothing to back that up other than what I've picked up about this car in various places and what I know about differentials.

I would check out the spark plugs ('glow plugs') at that mileage if they've never been done. Also, I'd look at the accessory belt and belt tensioner to make sure everything looks okay there, too, and possibly go ahead and plan on replacing those soon as a little preventative maintenance. Assuming it wasn't recently replaced.

Transmission...that mileage is pushing into the gray area of change it or leave it alone, as mentioned above. Personally, I would go ahead and change it.

Also, don't see that they flushed and refilled the cooling system, but that would be worth a look at some point. Doesn't necessarily have to be immediately as long as everything is working ok.

[negendahl]

Yeah, i think ill go with the transmission oil change, and hope for the best.

Thank you for the rest of the input - belt and tensioner, is there a simple way to check their condition?

Originally Posted by auburnf30x

That BMW claims the differential fluid is lifetime is correct...but I believe they should be changed out every 60k miles/100k km. I have absolutely nothing to back that up other than what I've picked up about this car in various places and what I know about differentials.

I would check out the spark plugs ('glow plugs') at that mileage if they've never been done. Also, I'd look at the accessory belt and belt tensioner to make sure everything looks okay there, too, and possibly go ahead and plan on replacing those soon as a little preventative maintenance. Assuming it wasn't recently replaced.

Transmission...that mileage is pushing into the gray area of change it or leave it alone, as mentioned above. Personally, I would go ahead and change it.

Also, don't see that they flushed and refilled the cooling system, but that would be worth a look at some point. Doesn't necessarily have to be immediately as long as everything is working ok.

[Zheez]

Belt is fairly easy to check on the N47 engines as it's right at the front although on the F30 the air filter at the front gets in the way and there is a cover over it. You'll need to unscrew and pull that back then get a torch and have a look at it as best you can to make sure there's no splits or cracks in the rubber and that it just generally looks alright. Here's a random pic to show what I mean:



They're dead easy to change on these engines - not had to do it on my F30 but I did it on my E90 with N47 and it just needed a socket wrench to hold and release the tensioner then a drill bit to hold it in place. The belt then just comes off and the new one slips on, access was not a problem and it was less than a 10 minute job all in all. As mentioned before it's a bit different on the F30 N47 as the air filter housing and a cover is in the way but should still be easy enough even with removing that.

Tensioner would usually be making some kind of noise if it needed changing, a squeal or some other kind of noise. If you can't hear any strange noises from the belt area at the front of the engine you're probably fine.

[thejeremyman9]

Originally Posted by Zheez

Tensioner would usually be making some kind of noise if it needed changing, a squeal or some other kind of noise. If you can't hear any strange noises from the belt area at the front of the engine you're probably fine.

Tensioner can also show excessive "jiggle"/wobble before making noise as a sign it should be replaced. Mine wasnt making any noise and BMW still replaced it under warranty when i told them it looked like it was moving more than it should be just at idle.

[negendahl]

Right, thanks for the additional info

Originally Posted by thejeremyman9

Tensioner can also show excessive "jiggle"/wobble before making noise as a sign it should be replaced. Mine wasnt making any noise and BMW still replaced it under warranty when i told them it looked like it was moving more than it should be just at idle.