My car was running a little hot (needle just below the white mark between the 175 and 250 points. Normally the needle stays just on top of the 175 mark.

I removed the radiator cap and found that the coolant level was about 2 inches below the bottom of the fill neck. What is the full mark? The manual is not that clear. To me the manual indicates about 0.5 inches below the bottom of the fill neck for the full mark.

I also checked the oil since low coolant usually means low oil. The oil was at the half way point between low and full. I am going to pass by the store and pickup some Rotella 15w40.

thank you all.

I had never heard this before, can you tell me more? Why would this be?
Thanks

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Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

The radiator has a visible "Notch" (An indentation like a "V"), the coolant level top should be level with the top of the notch. Oil & coolant levels are independent and on a vintage MB you should check the oil every time you add fuel. More often if you have a known consumption issue.

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Probably because the OP doesn't take car of his car by regularly checking fluid levels. He simply assumes that if one is down others will be also.

Thanks Tom. Exactly what I wanted to know.

Muleears:

I have found on my Volvo's that if the coolant level was down in the expansion tank by at least half then the oil level would be low as well. Also, I read many years ago that engine oil also provides a cooling function. If the regular antifreeze is low then always check the oil level as well. This is assuming that the actual cooling system is not loosing antifreeze due to a leak.