Need Advice | Expected Effects of Using Lower Viscosity Oil on VANOS

[Hasan Shaikh]

Guys

Need advice on the expected/possible effects on the NANOS if a lower viscosity oil is used in an S85 instead of the 10W-60.

Appreciate the feedback.

Thanks
Hasan

[Bruno]

oil does not affect vanos... you will damage everything else basically

[Hasan Shaikh]

Thanks Bruno!

What will be damaged? and why?

[Bruno]

http://www.bimmerfest.com/forums/sho...d.php?t=664511 useful info here

Rod bearings and o-rings premature wear are the first 2 things to fail

[Hasan Shaikh]

http://www.bimmerfest.com/forums/sho...d.php?t=664511 useful info here

Rod bearings and o-rings premature wear are the first 2 things to fail

The thread suggests that the engine failure was not caused by using a lower viscosity oil.

I am not sure about the 0-rings, but the bearings on the S85 and S65 have a very tight clearance. 10W-60 does not flow well enough to lubricate the bearings. This is why these engines fail a lot due to excessive bearing wear.

http://www.m3post.com/forums/showthread.php?t=892838

[Bruno]

in the thread i posted there was a guy who posted some graphs and numbers regarding oil figures. this is what i wanted to refer to.

in general the M engines are sensitive to the thickness of the oil and how they behave at various temps. anything outside the accepted zone will most likely cause premature failure of various components in the engine. the weakest components in our engines happen to be the O-rings and the bearings.


however this does not happen overnight, it will take time to start kill an engine.

[Hasan Shaikh]

Excellent point.

But the thing is, the extremely thigh clearance on the rod bearings of the S65 and the S85 does not allow proper flow of 10W-60 which causes excessive wear and catastrophic engine damage. Many engines have failed at around the 100k mark; and some even before that.

What do you think the o-rings will be damaged?

Thanks

in the thread i posted there was a guy who posted some graphs and numbers regarding oil figures. this is what i wanted to refer to.

in general the M engines are sensitive to the thickness of the oil and how they behave at various temps. anything outside the accepted zone will most likely cause premature failure of various components in the engine. the weakest components in our engines happen to be the O-rings and the bearings.


however this does not happen overnight, it will take time to start kill an engine.