Running synthetic BMW oil in a tii

[kmoy2002]

I have some BMW synthetic motor oil from when I owned a e46 and e39. About enough to do a oil change on the tii. I've been using conventional oil for this motor all its life. Will I do any harm switching to synthetic for one cycle and then switching back to conventional? Searching yields that I may experience leaks due to the lower viscosity of synthetic?

 

Thanks for your help.

[theNomad]

"BMW" oil is probably 0w40 to deal with tight tolerences and small passages, materials used in modern engines.

Go thicker for the M10, stick with 10w30 

Valvoline VR1 has the zinc and phosphorus that is best for the old stuff (I think I do have the 20w50)

IMO

http://www.valvoline.com/our-products/motor-oil/vr1-racing-oil

Search is your friend

Edited February 18, 2017 by theNomad

[MatthewCervi]

2 hours ago, theNomad said:

"BMW" oil is probably 0w40 to deal with tight tolerences and small passages, materials used in modern engines.

 

Yeah, I think that's the bigger problem here than synthetic vs. conventional oil:  oil for modern engines is completely the wrong viscosity for a M10.

['76mintgrün'02]

1 hour ago, ray_ said:

 

Personally I'd stick with 20W50 high zddp dino oil.

 

Anything thinner may cause issues IMO.

 

Cheers,

 

(Quote taken from the duplicate thread...)

I agree with ray_   20W-50 VR-1 for me : )

[dorwoon]

Just bought a case of 20W50 at a specialty BMW parts shop. They told me that my car probably leaks a bit (it does). They told me that my car would probably leak more if I used synthetic.

[gracer]

I have been using 10W-40w Amsoil in my Tii Since 1977.  There is no harm in using synthetic oil on a used engine.  I have 336K on my TII.  G

[jimk]

1 hour ago, gracer said:

I have been using 10W-40w Amsoil in my Tii Since 1977.  There is no harm in using synthetic oil on a used engine.  I have 336K on my TII.  G

You have me beat by one year and a lot of miles.  I use it now in the S14.

 

1 hour ago, dorwoon said:

probably leak more if I used synthetic

Need to talk to people that actually know something about oil instead of those passing along old wives tales.

 

6 hours ago, theNomad said:

"BMW" oil is probably 0w40 to deal with tight tolerences and small passages, materials used in modern engines.

A guess on 0W-40 because BMW only called for 5W-40.  They never bought from a supplier that would put the good stuff in to make a 0W-40 hold up.  It needs a better VI improver.  And at the rated temperature a 40 is a 40 is a 40 when it is new.  Trouble is the poor quality stuff ain't  40 for long. 

 

6 hours ago, theNomad said:

Go thicker for the M10, stick with 10w30 

A 10W-30 isn't thicker than a 0W-40.  Oils are not graded by shaking the bottle.

 

Use the heavy stuff, SAE 40 and higher because SAE 30 and lighter stuff is not for flat tappet cams, the EPA regulated out the anti-wear ingredients to not kill the catalytic convertors.   But heavy oil runs hotter due to drag. If the car is racing hard, then use something that has a high film strength.  Before catalytic convertors, the heavy stuff was the cat's meow years ago because the oils were much more volatile and the heavier stuff didn't boil off as much. 

[JohnH]

Well said jimk. There is so much BS out there when it comes to oil.

[Driv3r]

Nothing but Liqui Moli goes into any of my engines. For the Tii I was recommended SAE 20W-50 HD by local BMW Racing club.

https://products.liqui-moly.com/classic-motor-oil-sae-20w-50-hd-3.html

[gregpark]

After a couple of hundred miles on the break-in oil after a re-build many years ago I've run only 10/40 full synthetic for around 70,000 miles. No leaks and doesn't use any oil at all. I change it when it looks dirty and have never had to add. I'm a firm believer in full synthetic, it's just a superior form of lubricant.

['76mintgrün'02]

On 2/18/2017 at 10:47 AM, kmoy2002 said:

Will I do any harm switching to synthetic for one cycle and then switching back to conventional?

 

Any opinions about switching back and forth?

[jimk]

12 hours ago, '76Mintgrun'02 said:

Any opinions about switching back and forth?

No problems, unless the synthetic is a diester base stock (not all synthetics are created equal, just like tires are not equal).  The diester oil is a very strong detergent and was the start of the rumor about cleaning out a crankcase (and the cracks around bad gaskets).  The vast majority of "synthetic" oils on the shelf are either PAO or hydrocracked petroleum synthetic and do not clean out a gummed up crankcase.  It takes a good flush or something like AutoRX to clean it.

[Oldtimerfahrer]

Hi,
I used to run castrol gtx 20w50, but I went to fully synthetic 5w30 oil about 4 years ago without any issues. The valve cover gasket did leak until I replaced it. I do track days and hill climbs with no issues. My motor came rebuilt, I would not switch on a motor that had been run a long time with mineral oil due to deposits and switching to and fro doesn't seem like a great idea. If you drop the pan, clean it and the pump completely the risk is probably low. High mileage with sludge in the pan, hardened valve seals and other seals would not be a recipe for success.
Andrew

Sent from my HTC One using Tapatalk

[TobyB]

Personally, I try to pick one and use it.  No real reason other than I KNOW it won't interact with itself.

 

As to the leaks, of course that's an old wives' tale.  It also happens, especially when you do something

like change the diff and trans oil on something that's still got the factory fill in it.

(Yes, Marshall, the E46 again.  Transfer case and rear diff are now both leaking.  Teach me to change fluids)

 

t

 

[Guest C. Meister]

Yes, I would like to change my tii to synthectic oil so as to extend my change time. I only drive around 800 to 1000 miles a year and would like to change every other year. Any thoughts?