I've searched this and the bimmer sites, but I can't find much consensus on the proper procedure for checking oil level for synthetic oil, like Mobile 1 0W-40.

The common procedure is:

1. Run car to operatering temperature.
2. Turn off engine, and wait 5 minutes on level ground.
3. Clean off oil dip stick. Insert stick for 3 seconds, and remove for a reading.
4. Half-way between mark is best.

But, I've read that synthetic clings to the innards of the engine too well, so one must wait longer before checking the level. I've seen people suggesting waiting until next morning! What do you think? For synthetic oil, should I wait longer?

Instead of going through all the hoopla, why don't you check it before running the engine?
Regardless, the amount left clinging to the engine after 5 minutes would not make any difference anyway.

Just check it when the cars warm on level ground, thats it. It's not rocket science as long as it is between the marks.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

And it all came back.........but one table spoon.
Remember that cooking oil commercial?
Check your oil on level ground, first thing in the morning or a few minutes after shut-down.
The correct level is between the two marks on the dipstick, as you said.

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2007 C 230 Sport.

What a question.

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N. Hodges
1994 S350
1987 300 SDL (for sale)

Nothing wrong with the question, jasp, other than Mobile being a city in Alabama.

I have heard the same as you that synthetics should be left to drain back longer. I usually check my oil in the morning before I start the car and so it is done at the same inclination, etc. Of course, when traveling I can't do this, so I just wait as long as possible after shutting off the motor. My engine doesn't use any oil (knock on wood) so I've never had a problem.

What you might do is test it. See if there is an appreciable difference between first-thing-in-the-morning and 5-minutes-hot. If there is, just make the adjustment, assuming the morning check is more accurate.

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Steve

1992 300CE Sportline Sophie
1990 300E Emma - in the family
1979 240D Josephine - sold, but not forgotten
2004 Pacifica AWD

http://web.mac.com/dakota/Mercedes/Home.html

Checking the oil is the simplest of tasks: The tendency to over analyze is epidemic here: Shut off the engine with the car on a reasonably level spot, raise the hood, wait two minutes (with a warm engine), pull the dip stick, wipe it down, put it back, wait 5/10 seconds, pull it out again and read it.
If the level is between the marks, put it back and drive on. If the level is at the minimum mark add 1 quart and recheck as above. Add oil only when the level is at the minimum mark. Thats all. Synthetic or dino no difference.

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N. Hodges
1994 S350
1987 300 SDL (for sale)

Thanks all for the reply!

But even if there would be little difference in the amount that sticks between Dino and Synthetic, the disagreement as to whether the wait should be 5 minutes after warm or cold in the morning disturbs me. So far, I haven't been able to park the car for hours on level ground (both at home and at work the parking had been on an incline), so I'll have to try the cold method deliberately. I think I'll park the car level (like at the mall) and check 5-min later and several hours later and see if the level is the same. If it isn't, then at least one school of thought regarding how long to wait has to be wrong....

Egad. Why? I think you need a car that you don't have to obsess over

jsap a new MB would bother you they don't have dipsticks anymore!

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Yea, the new MB would strike me funny.

But I'm surprised that the issue of how to check the oil level (and esp. for synthetics) hasn't been beaten to death, and I'm surprised that I'm being accused of being too obsessive when we've got guys here adding resistors to their CT sensors, washing their cars with distilled water, fixing paint chips with toothpicks, worrying about too much K&N oil coating their MAF sensors, slicing apart their spark plugs for a closer read, and while I'm at it, why don't we all add an obsessive thing to the list....

Frankly, I'm don't just drive this car. And I don't get my hands dirty to save money. I'm in it for the fun, and if thinking about whether checking the oil level when cold vs. hot would yield any difference gives me something to do in my head, I think there'll be others who would agree. If you disagree, I'd rather that people respond with evidence that the two methods yield identical results rather than remarks as to how this is unnecessary....

Just my two cents....

'Cause its a none issue. I mean honestly how much sythentic is going to stick to the walls? 1/2 quart? I doubt it. 1/4 quart. Not likely. Much less I think.
I mean the next thing you know someone will be saying that the max line on the dipstick is too thick, I mean should the oil just touch the line or cover the line? And if we take the new shorter filter into consideration that just messes me completely up

The word "compulsive" comes to mind. Hot or cold the oil level will not be off enough to matter in the grand scheme of things. Hot oil runs down to the pan real fast when the motor is shut down! If it is between the marks leave it alone. If it is at or below the minimun mark add a quart. There is a TSB that says that the dipstick in most Benz cars is wrong and the car should never be filled to the top mark as that over fills the resevoir. I agree, it's a non-issue.

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N. Hodges
1994 S350
1987 300 SDL (for sale)

jsap

If you can see the difference ( without a magnifying glass ), in the two methods described above, please let us all know.

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2007 C 230 Sport.

I think oil is checked for 2 main reasons: 1) Do I have enough oil? 2) Is the engine burning/leaking/using oil? The first question does not require great accuracy to answer. The second question does require accuracy. However, all it requires is repeatability. So the main point is which ever way you do it, always check it the same way. I have a level garage and always check it after it has sat overnight. As previously mentioned, just be glad you even have a dipstick!! I wonder which part they will remove next?

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra