Service Interval Has Shortened

myshirt

I'm driving 08 520d.

Is there any reason the Condition Based Servicing would shorten my oil service intervals?

Like they were roughly 18k, 18k, 15k, 12k, 12k, 12k and now showing as 6k... surely not right... mpg has dropped to about 42 from 48 in recent times also if that has any bearing...

Anyone any ideas?

jimgoose

Mmm. That Intelligent Service Interval thing they have incorporates a load of coefficients and variables, such as engine RPM, oil temperature, various timings, mileage, etc. to compute the service interval. Has your usage pattern changed recently, e.g. lots of short hops, that kind of thing?

Chimaera

Any change in driving patterns recently? A lot of stop-start driving (city driving), with repeated engine start-stop cycles will shorten the service interval and punish you on fuel economy.

myshirt

No, my mix of driving is the same.

It's a head scratcher... at least for me anyway...

Stainless_Steel

My 520i petrol states 25k kms between oil changes at the start.

I change it once a year either way, only doing about 14k a year.

corkgsxr

Bmw need more money so they keep shortening it.

myshirt

Well if it's that, then that's underhanded.

Surely they wouldn't do that, there has to be some other reason.

Voodoomelon

Have you owned the car since new? I wonder if the age of the car shortens the interval.

Marcusm

It's called conditions based servicing; it's unsurprising that over time components might need to be checked or subjected to higher degrees of lubrication or filtering!

Gumbo

It's based on time and driving style too, not just mileage.

myshirt

What are the implications of just resetting it yourself? Can that be done?

I wonder will it actually reset, or will the CBS know what you done and just revise itself back to what it was.

F#cking 6k out of an oil change... it's a joke

myshirt

And BMW can't stick on their own number to next oil change can they?

Sher one car I looked at before (not to buy) had 120k with oil changes each 20k.
No flywheel problem. No timing chain issue. All bmw fsh. Just coming off lease.

BMW must have been creaming their pants with how well it went.

myshirt

Anyone any ideas? Are there any diagnostics out there that would explain it?

Casati

myshirt wrote: »

Anyone any ideas? Are there any diagnostics out there that would explain it?

My understanding is that the condition based servicing simply takes fuel consumption into account, as such if consumption has dropped then its shortening the interval. Sounds like something is up as that almost a 20% drop in economy- could be as simple as blocked air filter or could be more complex- e.g. engine management system. Best to get it into a garage for diagnostic

MuppetCheck

I wonder have you a timing issue causing the poor fuel consumption?

ShaunieVW

Get it scanned for fault codes. A proper scanner, snap on modis or similar will pick it up. Dont bother with the hand held muck. This should highlight any issues and you can go from there. Id also ignore these 25k or 30k services. I am a firm believer that cars should be serviced every 10k miles max or once a year regardless of mileage. Especially the newer diesels with contrary turbos and dpfs.

bazz26

You'd want to be a brave man pushing the service interval out to 30k km on a N47 engine.

OP, was the correct grade of oil used at the last service interval?

myshirt

Correct grade of oil was used yeah, insofar as is listed on the invoice. Don't see any reason for the guys to have tried to pull a fast one there, they put in the correct oil.

When the service interval was reset it reset to 10,000, but only 2,000 miles later it is down to 4,000.

I would always service the car every 10/12k miles - I wouldn't stretch it to 20,000 miles at all, though as I said I did see a car that only had 6 services up to 120,000 and all good. It's the luck of the draw with these things, what happened to enjoying driving a car?

jimgoose

myshirt wrote: »

...what happened to enjoying driving a car?

Das ist Verboten. Enjoying is irrelevant. We will add your mechanical and biological distinctiveness to our own.

Gumbo

myshirt wrote: »

What are the implications of just resetting it yourself? Can that be done?

I wonder will it actually reset, or will the CBS know what you done and just revise itself back to what it was.

F#cking 6k out of an oil change... it's a joke

myshirt wrote: »

And BMW can't stick on their own number to next oil change can they?

Sher one car I looked at before (not to buy) had 120k with oil changes each 20k.
No flywheel problem. No timing chain issue. All bmw fsh. Just coming off lease.

BMW must have been creaming their pants with how well it went.

myshirt wrote: »

Anyone any ideas? Are there any diagnostics out there that would explain it?

You can reset it yourself using the iDrive and/or speedo reset button. There is no implications to it, as long as you keep not what date/mileage the oil was actually changed at so you can change it again at an appropriate time.

The reason the CBS alters is due to your driving style, times between the last reset etc

You cannot reset the system to a value that suits you, you reset it and it resets to the defaults mileage for next oil change.

One thing OP, I'm wondering if your oil has been reset correctly but you are now seeing 4000 to a different service item. For example, I reset the oil service interval on E60 but it was still showing 2k to an inspection service which I reset to coincide with the NCT dates. Maybe your mixing up what exactly the car is flashing up for?

Maybe you could post a picture of the iDrive screen which lists the service items and distance remaining to each?