Mercedes-Benz Forum banner

1 - 11 of 11 Posts

·
Registered
E-Class 320CDi Estate, 2000 model
Joined
·
14 Posts
Discussion Starter · #1 ·
Hi all,

I'm a newbie who posted this on the wrong forum, but have been kindly directed here.

I've just picked up an E-class 320cdi estate car, year 2000. The display tells me i have 1 malfunction - 'reduce oil level' - another forum member has suggested it may be as simple as draining off some of the engine oil - when i dipped it today the level does seem high - has anyone else come across this? Is it quite common?

Thanks.
 

·
Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
Joined
·
17,193 Posts
Streetglower, if we drive our cars with this message, what are the possible consequences? My dealer did the same thing to me.
 

·
Registered
2002 honda civic (sold), 2009 Mercedes ML350
Joined
·
1,344 Posts
if the car gives you the reduce oil level, take some things into consideration. if you just got an oil change chances are the oil level is a bit high. reducing it may be the answer. if you had an oil change 3-4k miles ago and the reduce oil light comes on, possibly the level is high or the sensor is bad. driving with that light coming on isnt going to damage anything. unless your oil level is 2 -3 quarts more then what the car calls for then you have a problem. personally if i had a benz with no dipstick i would buy the dipstick for an added assurance. the system is good, but when i change my oil i want to physically see the level.
 

·
Registered
E-Class 320CDi Estate, 2000 model
Joined
·
14 Posts
Discussion Starter · #5 ·
Thanks for that reassurance - i'll siphon off some of the oil and see how it goes
 

·
Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
Joined
·
17,193 Posts
Thanks Streetglower. The car's electronics say OIL LEVEL O.K. when it is cold, but after driving is when I get the REDUCE OIL LEVEL message. I recently had them start an oil consumption test and I spoke with the technician. He said the proper procedure is to change the oil, and have the level at the dipstick full mark. I checked it and it looked like it was above the full mark to me but he insisted that it is not and could never see the REDUCE error. I just completed the 2nd phase and I used less than the .8L/1100 km so the test is finished. I am still getting the REDUCE message after driving. Now it looks like the tech topped it off after the measurement when he didn't need to. During the 660 miles I drove the car consumed a little less than .5L so effectively, I should have siphoned off that much and the error would be gone. I'm not positive, but I think the oil level sensor is functioning properly.
 

·
Registered
1996 Silver C36
Joined
·
543 Posts
The generally accepted wisdom is that if your drive with your oil level overfilled, you WILL damage your engine. That is probably why Mercedes incorporated a warning of overfilled oil and also warn you not to do so in the operators manual. But hey! What do they know?

In general, oil is stored in the wet sump and is pumped around your engine for lubrication (and cooling) purposes. If your oil sump is overfilled, the crankshaft will be able to reach and beat the sump oil into a froth. The oil pump is not very good at pumping froth, and anyway froth is not very good at lubrication.

(There are some very sub-standard techs amongst the Mercedes Dealers. I think they only use the good guys for difficult jobs. I even had someone at my dealer put the wrong spark plugs in my C36...how basic can you get for a tech?).
 

·
Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
Joined
·
17,193 Posts
Thanks for the info OzC36,

I started a similar thread when I first noticed that message. Like you, another guy said the crankshaft beats air into the oil and also that frothy oil does not hold pressure well. I asked the service writer about that and he said the newer oils have some "anti-frothing" additve so I need not worry about it. Nevertheless, I think it is a cause for concern so I am driving at low revs until such time that I no longer see the warning. In fact, I did not see it yesterday after a few minutes of moderate driving so I think the level is back to the MB sensor's acceptable level.
 

·
Registered
2002 honda civic (sold), 2009 Mercedes ML350
Joined
·
1,344 Posts
Thanks Streetglower. The car's electronics say OIL LEVEL O.K. when it is cold, but after driving is when I get the REDUCE OIL LEVEL message. I recently had them start an oil consumption test and I spoke with the technician. He said the proper procedure is to change the oil, and have the level at the dipstick full mark. I checked it and it looked like it was above the full mark to me but he insisted that it is not and could never see the REDUCE error. I just completed the 2nd phase and I used less than the .8L/1100 km so the test is finished. I am still getting the REDUCE message after driving. Now it looks like the tech topped it off after the measurement when he didn't need to. During the 660 miles I drove the car consumed a little less than .5L so effectively, I should have siphoned off that much and the error would be gone. I'm not positive, but I think the oil level sensor is functioning properly.
usually what happens is the car has a min and max oil level setting in the control unit. say for example 24-43 mm. with the engine at idle the level should be between the 2 readings. when the engine is fully hot it should be about 3-5 mm under the max spec. now if the engine is cold and the level is at 42-43 mm, it will say ok, but if after the engine warms up the level is at 50 mm, the light may come on for redule oil level.
 

·
Registered
1996 Silver C36
Joined
·
543 Posts
If you want, you can easily drain a bit of oil out using one of those hand operated plastic siphon tubes through the dip-stick access.

Put the drained oil back in again in a few thousand km when the level drops a bit.
 

·
Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
Joined
·
17,193 Posts
Thank you Streetglower and OzC36.
 
1 - 11 of 11 Posts
Top