Oh, for a good old dipstick!

I drove to work (27 miles highway), parked, and came back outside 10 minutes later to check the oil. Diagnostic screen told me to add 1 quart to reach full capacity. OK, I'll grab a quart at lunch. Went to Autozone, parked, bought the oil and looked around a bit. Came back to the car after 10 minutes, checked the screen and now it tells me the oil level is fine. WTF? Since then (Tuesday), I have checked it twice every day after highway driving (and observing the waiting period) and readings are always inconsistent. All I can think is that 1)the engine oil level is bordering on needing a quart, or 2)the system is unrealiable and not to be trusted.

Thoughts?

 

Add a little and see if it stops happening. If it does, then the oil level was indeed a little low - around the point where it might need a quart or so, but the system couldn't measure it with any better accuracy.

 

V, are you saying that, in your experience, you believe the system does a good job gauging the accuracy of the oil in the pan?

 

Verify it using the dyno mode and see what you get.

 

I don't know. I had a situation like that, too. Was cured by adding half a quart of oil. But my car also has a dipstick, so it is easier to check in my case. However, when a low oil alert message appeared on the screen, the oil level indeed was a little low.

 

You need to be parked on flat, even surface, even a little uphill or downhill could give you wrong results.

 

I've had this happen once while driving, got the low-oil level alert. I checked the actual level with dyno mode and it turned out I was a little low, yet not down a full-quart.

Rapid acceleration, hills, and weather seems to affect the reading so use dyno mode to verify hw much there is first before you add a full quart. Usually you'll only need 1/2.

 

After an extended oil drain from the sump plug and replacement of the filter I added measured amounts of oil at intervals to check the accuracy of the dyno mode. Here's what I got:
Added Dyno Mode Readout
6 qts. 5.8
1 qt. 6.7
.5 qt. 7.1
.5 qt. 7.5
Started engine and ran for 3 minutes
none 6.5 (filter fills up)
.5 qt 7.2
8.5 qt. total put in

This is consistent with what I was getting after MB serviced the car as well. I believe the oil level sensor is accurate but I'm not too sure about it's calibration.

 

Could someone please explain what Dyno Mode is? I can't find it in the manual. (I checked TFM before posting)

Thanks.

GGM

 

Also, could someone please clarify if the car does a check of oil level on its own? Does it do one after shutoff and store messages for the next startup? Or is it something that I must do on my own on a regular basis. Again, I checked the manual before posting.

Thanks.
GGM

 

apparently is accessed differently depending on what year/model you drive. One of the features is checking oil level to the .1 quart/liter. search on dyno mode in this/w203 forum.

 

I don't mind the auto oil sensor, but for the life of me, I don't know why they couldn't give us a dipstick. I was told by my service person that the '05s have a dipstick, though I'm not sure he's right.