Oil change interval BMW turbo

[tennisdoc40]

Posts on the site said that the oil change interval for the BMW 3 liter turbo was 15k. Just had the oil change at the dealer, and the oil service indicator is at 21,000. There was a lot of debate whether a hot running turbo could go 15 k at all.
Rob

 

[JHZR2]

You need to give a lot more info. Is this the N54 3.0L twin turbo?

Id want to cut the interval back because iterations of DI in the USA are not lean stratified charge due to fuel quality.

That said, ive not seen many useful N54 used oil analysis.

 

[Ken2]

How much oil in the system, and what is the quality of the oil. More oil means that more is sitting idle in the sump while awaiting its turn to lube the engine. This adds to oil drain time. For example, a conventional car with 5 quarts and 3000 mile oil changes. Put on a 10 quart sump and you've immediately gone to 6000 mile oil changes with exactly the same deterioration of the oil. (I know--don't flame me with the 3k ODI...I'm just making an example.)

Highest quality oil deteriorates more slowly than ordinary oil. That also adds to the oil drain interval.

Regarding heat and oil--time at temperature is a huge factor. How long the oil is held at the high temperature as well as how high the temperatures are makes the difference. If the turbo is (a) water cooled, and (b) has very adequate oil flow so the oil doesn't get really hot, and (c) very high quality oil that deteriorates less when hot, and the result is little damage to the oil.

 

[mechtech2]

21K is a lot of miles on oil.
I would have changed it long ago.

 

[Steve S]

The heat from the turbo is really over rated especially when running a syn oil. 10,000 miles oil changes should protect your engine. Doing a used oil analysis at the oil change would tell how the oil is holding up

 

[saaber1]

Originally Posted By: tennisdoc40
Posts on the site said that the oil change interval for the BMW 3 liter turbo was 15k. Just had the oil change at the dealer, and the oil service indicator is at 21,000. There was a lot of debate whether a hot running turbo could go 15 k at all.
Rob

Wow that is a lot of miles on oil in a DI engine that is known to have valve deposit issues and according to Terry Dyson wears out oils like M10w40 in 1000 miles.

Wow. I foresee some valve cleaning in your future.

I'd like to hear JAGs input as he follows that engine pretty close.

 

[tennisdoc40]

Yes this is the N54 Turbo. Up till now, I have split the difference with BMW, paying for my own oil changes with their extended life fully synthetic at 7500 miles. The last oil change was on their dime, but the reset is at 21,000. This seems like 5,000 more than their usual. I'm going to do the oil change in 7500 miles.
Rob

 

[d00df00d]

Do you baby it when you drive? The OLM takes a lot of variables into account when computing the OCI.

Anyone know if this OLM has any sensors in the oil? Maybe the 7500 mile changes are confusing it.

 

[shpankey]

You are a much braver man than me. Direct Injected Turbo? That beats the heck out of oils.

 

[d00df00d]

Guys, he's not actually changing it at 21k miles. He said he's changing it every 7500. He just noticed that the OLM went that long and is asking about that.

 

[Craig in Canada]

A lot of people are bringing up valve deposits. I'm not sure I see a connection between whether you do 3k, 5k, 7k or 15k OCIs and the degree of valve deposits. Have we seen evidence that the rate of accumulation of valve deposits increases as the chosen oil ages?

 

[JHZR2]

Originally Posted By: saaber1
Originally Posted By: tennisdoc40
Posts on the site said that the oil change interval for the BMW 3 liter turbo was 15k. Just had the oil change at the dealer, and the oil service indicator is at 21,000. There was a lot of debate whether a hot running turbo could go 15 k at all.
Rob

Wow that is a lot of miles on oil in a DI engine that is known to have valve deposit issues and according to Terry Dyson wears out oils like M10w40 in 1000 miles.

Wow. I foresee some valve cleaning in your future.

I'd like to hear JAGs input as he follows that engine pretty close.


Do we really have all that info from the N54?

 

[JHZR2]

Originally Posted By: Craig in Canada
A lot of people are bringing up valve deposits. I'm not sure I see a connection between whether you do 3k, 5k, 7k or 15k OCIs and the degree of valve deposits. Have we seen evidence that the rate of accumulation of valve deposits increases as the chosen oil ages?





+1 good point. Assuming that the oil "distills" by volatility, as it ages, the rate of depositing should go down, and the total amount of deposits should get fairly high fairly quick after some time at operating temp.

 

[saaber1]

Originally Posted By: JHZR2
Do we really have all that info from the N54?

Yes, lots of reports from BMW dealers on the N54 and the v12. Although certainly the quanitiy of evidence is not as large as for the audi/vw DI engines.

Dyson apparently has been on top of it for quite a while for the n54:

"reb03, the Mobil 1 0w40 should not be run longer than 1000 miles to be safe.. Audi and BMW know they are having problems but are marketing tied to certain LARGE oil company that sponsors BITOG thus they cannot speak out about it."

"reb03, I have customers running BMW5w30, Mobil 1 0w40 all with the same effect, the wear control is good if we change the oil at 1000 mile intervals but the deposit formation from REAL volatility issues are slowly damaging the engines. I just worked a 07 335 Biturbo yesterday USING ASTM lab tests on the used oil and Mobil 1 0w40 went from VOA flash of 430+F to 280 F in 1150 miles, oil sheared to 12.1 cSt and fuel was at 1.99% by IR."

Found in this thread:

http://www.bobistheoilguy.com/forums/ubb...1179#Post981179

 

[buster]

Clearly a design flaw more than an oil deficiency, assuming Dyson is right.

 

[JHZR2]

No, the flaw is that we have relatively high sulfur gasoline, and so cant run a lean stratified charge like they do in other places. As a result, combustion is not correct per the design of the CC and engine. This yields issues.

You can thank our EPA who thinks that a few ppm of NOx in CA is more important than gross tonnage of everything under the sun... The same group that says that a 12 MPG expedition is a "partial zero emissions vehicle", and a 44 MPG jetta diesel is a "gross polluter".

 

[saaber1]

Yep, in the US NOx is everything, stemming from smog/air pollution concerns.

In Europe, etc. CO2 is everything, stemming from global warming concerns.

Has anyone ever seen "Dimming the Sun"? It is a NOVA DVD and available at some libraries or amybe download at PBS?. The conclusion was that particulates in air pollution such as that in China is making more clouds worldwide which is making the surface cooler. This is masking the effect of global warming.

Also interestingly, on 911 when all the planes in the U.S. were grounded, temps (the range between high and low) rose in the U.S.

Worth watching if you are interested in that sort of thing.

 

[CivicFan]

Jeez, I can't believe I am seeing a 1k OCI for Mobil 1 0W-40. What is this, 1925?

The 3.2l DI engine in our A6 has seen 10k mile changes with no ill effects. Good oil like GC or Mobil 1 0w-40 makes oil related issues the least of the problems in a modern car.

 

[Nederlander75]

Pull the valve covers off and say that again.