I changed my engine oil today (now 4500 mile intervals with Synthetic). Before I sucked the oil out, I checked the engine oil level. It was below the MIN mark. In fact, it was almost to the very bottom of the dipstick (the red rubber part). I know my oil level light works, because when i drained the oil, and turned ignition to position 2, the OIL light did come on.

First question, how low does the oil have to get for the light to come on? Maybe the sender unit is a little out of line or something?

Secondly, I have always noticed a small amt of oil consumption, I do check it periodically, but probably hadn't in 2k or more miles. I am assuming since my longer oil change intervals (4500, before it was 3000), that is why it seems there is more oil loss. Also, really drive my car hard, with a lot of high RPMS, and a lot of high revving fwy miles. So this all makes sense, right? To be burning this much oil? I do know that I am not leaking any though. I use a mix of 15w 50 and 10w30 usually. Is synthetic oil more likely to burn off than dino? Thanks for the help.

BTW, I know have 98,700 miles.... on M104 motor, C280.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

David, if I understand you correctly, you mix oil grades?
I have always read not to mix oil grades.
I figured it was meant to maintain
homogenous Temp. protection, but who knows?
As for the oil usage, no educated guess from me.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

I knew that would come up... I know it's not "recommended to mix oil" but I can never find exactly what I want. I am SURE my car will be fine!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

I think I heard at Cartalk (could be somewhere else) once that mixing oil grade is OK. I tried to find it in their archives this morning but could not.

They even said the viscosity index is a pretty linear scale. In another word, if you mix 1 qt of 5W30 with 1 qt of 15W50, you get 10W40.

Bo

my oil lamp comes on when i need to add a liter.
i used to add a liter in between oil change, but with
20W50 i haven't add any.

David,
I had a bad leak experience with synthetic. It made my valve cover gaskets start leaking on my Passat almost immediately after I switched at 24k miles. It was never the same - they never quite fixed it, they tried 7 times and replaced the gaskets 4 times. Never mind, that will soon be in the past as that lease is over soon. One thing about synthetic though is that my veedub did not use any oil with synth while it always does on dino. I will probably use synthetic only if the car started with it or if it's early in a cars life...

The oil level light on the M103 in my 4matic will only light after the engine has warmed up. I think it's a conductivity measuring device and it's probably cal'ed for hot oil. It's supposed to come on when fluid is at the bottom of the dipstick, but I've heard of complaints both high and low.

As far as mixing oils, SAE designations require "miscibility" among all other approved oils in order to get SAE approval. Don't worry about oil and vinegar scenarios in your engine.

HTH

someguyfromMaryland

Do any techs know exactly when the light is supposed to come on? Right below the MIN level? Or near the bottom of the dipstick?
Thanks.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

I had the light come on once and it flickered rather than stayed on. The oil level was right at the MIN level.

Bo

Close to the same happened to me with my w126.
Flicker alerted me to the need of
2 quarts.
Some filks claim the light goes on
when you reach zero, like that riddle:
what time is it when an elephant
sits on your fence?
Time to get a new fence.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD