Synthetic and oil level reading

Jul 11, 2005 3 Replies
J

Since I filled my 1991, 750iL with Mobil 1, 0W-40, the low oil level alarm has started going off when the (overnight) dipstick level is 1/4 of the way down from the high mark.



I have heard that synthetic oil "clings to the surfaces", and thus takes longer time draining to the oil pan compared to conventional oil, and this seems like a confirmation of that. It probably takes 6 hours to get a repeatable oil level reading, prior to that, the level slowly increases.



Has anybody else seen this, and if it is true that synthetic oil drains down slower, would the optimal oil level be higher than for conventional oil, or would the risk of overpressure exist during startup?



Jan Fure



Vote
Twitter Facebook LinkedIn
S

I have never heard that synthetic "clings to surfaces" and takes longer to drain but I do know that synthetic oil will sneak past worn gaskets or valves much faster than conventional oil, which is why I didn't change to synthetic on my 150k 525i. In my experience, synthetic flows quite rapidly especially in cold weather.

- Scott

"Jan Fure" wrote in news: snipped-for-privacy@o13g2000cwo.googlegroups.com:

Vote
Twitter Facebook LinkedIn
H

I think you read too much science fiction.

Huw

Vote
Twitter Facebook LinkedIn
M

This is an urban legend, IMO. A synthetic maintains viscosity closer to its rated value(s) over the lifetime of the oil. There is no reason to believe it will leak past gaskets more than a thinned out dino juice.

The only *possible* reason for this oft quoted legend would be that the superior cleaning properties of the synthetic may actually disolve some of the gook that has built up inside a higher mileage engine previously subjected to only cheap oil. That gook could be sealing your dried out and leaky gaskets, but I have never experienced this phenomenon and I've switched several high mileage cars (over 100k miles) over to full synthetic with no leaks or increased consumption.

-Fred W

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required