Hello,

2017 G550 purchased last year. No issues for first 3000 miles, then when driving in cold I got a notification to reduce oil level. Was due for an oil change anyways so I took it in for the oil change, but got the notification again on the way back from the ski resort. Incidentally noticed misfiring also so I had the car taken back to the mechanic, they checked oil and replaced ignition coils under the coil warranty. Since then I still get the engine oil level reduction warning but it has only popped up when driving in cold weather (anything 5c or colder). Not sure if the cold throws off oil levels or if I should get this checked elsewhere?

 

Sounds like a faulty level sensors.

Trenton O. Gibson
tgibson@highline-autos.com
Highline Autos
Direct: 602.909.9216
Office: 480.348.0777

 

It sounds like you may have a couple of issues at play. The cold weather can affect oil viscosity, which might trigger the warning if the oil is too thick. First, check your oil level when the engine is cold to ensure it’s at the proper level. If it’s fine, consider having the oil and filter changed again, using a synthetic oil suitable for colder temperatures.

If the problem persists, it might be worth getting the oil level sensor checked, as it could be malfunctioning. Lastly, if the misfiring continues, it may be related to the ignition coils or another underlying issue that needs attention. Take it to a trusted mechanic who can diagnose the problem further.

 

Cold weather can trigger a rich air/fuel ratio till engine get the working temperature, so the oil dilution can happens if you drive very short distances.

Anyhow, sometimes a SW update can sett a different offset for oil level sensor.

Rarely but it worth checking, another SW update can make the heating management less aggressive, so the dilution will be reduced.

To choose between sensor offset or engine heating management, you can..."smell" the oil if the gasoline flavor is present.

 

Thank you all - I will see about changing the oil one more time to see if that fixes the issue, I've just been having the oil done at the dealership and letting them use whichever oil they recommend; I live in the PNW so not sure which oil they typically use but I would assume it's synthetic?

Misfire has been fixed since swapping out the ignition coils so that is all good.

No gasoline flavor on oil smell, and they did update the software last time when I brought it in for the 50k service. The oil warning always pops up after about 20-40 minutes of cold (under 5C) driving.

 

Update: have had the car looked at by an additional dealership which said they could not see any issues and said the car is in great shape. Car seems to be driving fine, took it on a 6 hr road trip and had no issues beyond the warning popping up 1-2x each way (not in cold weather this time, about 15C). At this point I am suspecting a sensor issue; assuming the car is safe to drive?

 

Your '17 G550 has the M176 engine, as does my '19 G550. My OM lists the oil capacity as being 10 qts. That might be the capacity, but the refill quantity is 9.5 qts. Possibly just a bit too much oil was put in with your last oil change, hence the intermittent indication (electronic sensors are less precise than a plain old dipstick). If you have a "Workshop" menu accessible on your instrument panel, you can access a screen that provides an oil measurement in liters, which might help in this determination. Search the forum for "workshp menu" to see if you're so equipped and how to access it.