Mercedes and synthetic oil question
Mercedes and synthetic oil question
(OP)
I have a problem/question about the use of synthetic oil in an slightly older Mercedes.
My father in-law has a 1997 E320, v6, bought used at 111K miles. It now has about 117K miles and last summer the "Low oil" warning started coming on even though the oil as checked manually was fine.
He finally hit upon a cure, don't use synthetic oil. I believe synthetic oil is specified in the owners manual.
Unfortunately I forgot and yesterday had the oil changed for him and had them put in synthetic, now the light is on again. Unfortunately I don't know what weight synthetic oil was used. There's no lifter noise, no bearing noise as far as I can tell it is running fine.
I have an appointment tomorrow to have the oil changed again, to non synthetic.
Here's my questions: What is triggering the low oil light? Low oil pressure because synthetic is easier to pump? Is the oil to "clean" and does not register on some kind of optical sensor? Is there any problem running non synthetic oil?
I hesitate to take it to be scanned by the dealer, $100 to tell us "it thinks the oil is low".
Thanks.
My father in-law has a 1997 E320, v6, bought used at 111K miles. It now has about 117K miles and last summer the "Low oil" warning started coming on even though the oil as checked manually was fine.
He finally hit upon a cure, don't use synthetic oil. I believe synthetic oil is specified in the owners manual.
Unfortunately I forgot and yesterday had the oil changed for him and had them put in synthetic, now the light is on again. Unfortunately I don't know what weight synthetic oil was used. There's no lifter noise, no bearing noise as far as I can tell it is running fine.
I have an appointment tomorrow to have the oil changed again, to non synthetic.
Here's my questions: What is triggering the low oil light? Low oil pressure because synthetic is easier to pump? Is the oil to "clean" and does not register on some kind of optical sensor? Is there any problem running non synthetic oil?
I hesitate to take it to be scanned by the dealer, $100 to tell us "it thinks the oil is low".
Thanks.





RE: Mercedes and synthetic oil question
<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying " Damn that was fun!" - Unknown>>
RE: Mercedes and synthetic oil question
http://www.whnet.com/4x4/oil.html
A Mercedes with 100,000 miles on the clock is still "new" in my book. My wife's Lincoln has 158,000 and is still on 5W-20 synthetic and uses no oil between changes! Perhaps you have purchased a car that is the victim of abuse or an unscrupulous dealer that 'turned the clock back'?
Rod
RE: Mercedes and synthetic oil question
RE: Mercedes and synthetic oil question
Mixing between synthetic oil or standard oil makes no difference. Technically, it will always be in a mixed state knowing the fact you can never completely remove all the oil out of an engine simply at oil change time, albeit the percentage of removed oil will drop each oil change.
Now some engines require synthetic for different reasons such as better thermal breakdown qualities, clearance protection, friction reduction, heat transfer capabilities and so on. Generally, the higher the performance (and newer the car), the more likely it will require synthetic oil. Newer, higher performance cars have closer tolerances, run at higher temperatures and push the engine to greater extremes compared to an older car of similar engine size.
Besides, it makes for one hell of a marketing push; "Mobil 1 Synthetic, the Official Oil of NASCAR".
Kyle Chandler
www.chiefengineering.net
RE: Mercedes and synthetic oil question
- Steve
RE: Mercedes and synthetic oil question
Kyle Chandler
www.chiefengineering.net
RE: Mercedes and synthetic oil question
RE: Mercedes and synthetic oil question
Kyle Chandler
www.chiefengineering.net
RE: Mercedes and synthetic oil question
If it were a float type gauge the type of oil could have no influence except for a slight difference in float height if there is a difference in SG.
If it were an electronic sensor type gauge, then a change in the conductivity or polar nature of the oil might upset it, so I expect that is the answer.
If the oil level is showing low, but known to be OK, just pull the wire from the indicator and occasionally check the dipstick. Problem solved.
Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers for professional engineers
RE: Mercedes and synthetic oil question
RE: Mercedes and synthetic oil question
RE: Mercedes and synthetic oil question
I'm just getting a '99 E320 112K, so I am looking at its service history and this thread with interest.
These articles may be of interest:
http://ezi
http:/
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
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RE: Mercedes and synthetic oil question
RE: Mercedes and synthetic oil question
Once the warning comes up it stays up until a shutdown and restart. It also doesn't come on at idle but instead during normal driving. Finally the message completely obliterates the mileage information. And I'd aslo wager that if the wire was disconnected there would be a different area.
As an aside, which is not on topic, but in general I find that Mercedes spent needless time on "fussy" engineering. This being an example. Why not just leave it at low oil pressure? Real time oil quality monitoring? What's the point?
RE: Mercedes and synthetic oil question
80% remaining is about 2000 miles for a lot of highway use, or something abusive after resetting the maintenance reminder light.
RE: Mercedes and synthetic oil question
in your particular case either the sensor could be at fault or the software used. a mercedes repair shop should be capable to check both.