# Engine oil too full



## Froodle (Jul 2, 2021)

Is my theory correct on how the engine oil could now be over maximum feasible?
How do I remove just a small amount of engine oil to reduce it down to maximum (also to check the oil) – the B57 doesn’t have a dipstick, so no obvious places for a syphon.
Does diesel in engine oil have a major detrimental effect – I.e. should I do an oil change? (I know for safety sake I should, but could I get away without doing it for a couple of months until we get nicer weather)?

Many thanks 😊


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## Doug Huffman (Apr 25, 2015)

Yes, diesel in the crankcase oil has a detrimental effect and *indicates a severe problem* - beyond needing an oil change.

The Oil Level Condition Sensor / Quality Level Temperature Sensor - OLCS / QLTS - is notoriously buggy. There is a PuMA Measure regarding improper OLCS indication.


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## alacey (Mar 14, 2018)

Diesel(and gas) in oil is common on direct injected engines that constantly do short trips because the oil is not getting hot enough to burn off the fuel. If your daily commute is less than 15 minutes, then you likely are not getting your oil up to operating temp long enough to burn off the fuel and it is recommended to do a 30 minute drive on a regular cadence. 

Fuel dilution is even worse on some emissions equipped diesels that have an added injection event on the exhaust stroke in order to get the DPF hotter while it is in an active regen. Fuel dilution can do some serious damage to your engine over the long term. You are essentially lowering the viscosity of your oil so that means less lubrication for metal to metal contact points. If you are doing long trips on a regular basis and there is still fuel dilution then you may have an injector issue. I would change the oil and send it to a lab like Blackstone to get a used oil analysis to see how ban the fuel was diluted.


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## Froodle (Jul 2, 2021)

Many thanks. I found that BMW have hidden a dipstick on the B57 engine (back right hand side under “stuff”, and I checked and oil colour looks ok but a little too diluted for me. Time for an oil change - but yippee. I can use my syphon down the dipstick tube - much easier. I’ll do a proper sump plug drain in the summer when the weather is nicer

and thanks also for confirming my thoughts on short trips. A 7 series is not a practical short trip car, but who needs practicality hehe. And with Covid restrictions lifting in the U.K., I can get back to my long motorway runs to see my customers again


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## Pierre Louis (Oct 23, 2011)

My question is how much "over max" oil fill is tolerable. I would imagine one quart (or liter) above "max" is still tolerable. Does BMW have a "safe buffer" for this situation? Thanks.


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## mjez (Jan 16, 2014)

Pierre Louis said:


> My question is how much "over max" oil fill is tolerable. I would imagine one quart (or liter) above "max" is still tolerable. Does BMW have a "safe buffer" for this situation? Thanks.


I would imagine MAX fill line is there for a reason and should not be exceeded. The tolerance you're speaking of is most likely the area between MIN and MAX fill. Better to be in the middle than over.

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## Froodle (Jul 2, 2021)

When I had my “too full” warning, I syphon Ed off about 4L and replaced with new oil to about 75% full. I did have some whitish gunk on oil filler cap and panicked over coolant leak but I cleaned it and I’ve run the car for a month now - no new gunk on oil cap (big phew) and oil level static at 75%. So my thoughts on failed DPF regen seem to be perhaps accurate. I’ve done 2 regens in the last month and both worked fine and the DPF sensor PDIs say it’s clearing the soot out. So I’m feeling a bit easier. 
im planning an engine oil flush (118K miles on the clock so far) in a month or so, so will do new filter and full new oil then.


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## Pierre Louis (Oct 23, 2011)

My topsider device failed so I put too much oil in. Will change it again after I try a new device.


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