What's your problem?anti freeze & oil mixing in the engine mercedes e350

Do u see any signs of white ehaust,the engine running hot or oil & anti freeze mixing together? If so HEAD GASKET (burning coolant

A few things could have happen,
1 you overheated and blew the head gasket and now the oil in mixing with the anti-freeze,
OR due to high Mileage the head gasket has just failed and is leaking into the anti-freeze journals inside the engine.,

Did you check the oil to make sure it's not a white'ish sludge on the inside of the cap, you might be mixing both back and forth..

You could have serious trouble with the engine losing that much anti-freeze. If it is not leaking out somewhere onto the ground, it may be from a bad head gasket that is letting coolant burn in the cylinders (you would see white smoke out the exhaust), or it may let the coolant get mixed into the oil in the lower engine's crankcase.
Pull the oil dipstick and look at it. If the level is way high, or if the oil color is milky brown looking, then you have water (anti-freeze) in the oil-a bad head gasket, and a big expense to fix it. That would explain the rattling: water in the oil stops the oil from lubricating properly, and the engine bearings and other moving parts inside the engine can be damaged. If this is the case, and the reason for the rattling, then the engine is shot and needs a total overhaul, or you need a different engine.
If the coolant was leaking outside, post back. Has the engine ever overheated from low coolant? The rattling is worrisome-have a mechanic listen to it if you get it started. If it won't crank over, have someone see if the engine can be turned by hand-if it still turns freely (not siezed up), then the starting circuit needs to be checked for why the starter won't work. Good luck. Check the oil first thing.

Could be time for a new van.
The oil light is warning the driver engine oil pressure has dropped below 10 psi, not necessarily that the engine is low on oil.
Common causes for low oil pressure is a faulty oil pump or screen, or worn engine parts.
The fact you are also adding coolant and you don't see any external leaks sounds like the engine is reaching the end of its life.

I'd check the oil and see if you have any "cream" or discoloration of the oil as well.
Sounds like you may have oil mixing into the water...(usually looks like a chocolate milkshake.)
If this is the case, you may have a warped head (from getting too hot) or there might be an area where the water & oil jets are close and merely separated by a gasket. (i.e. Ford's 4.6 oil filter & upper water hose housing.)

Oil in water or water in oil either way isn't too good.

If after checking oil and its not "creamy" as well...maybe a good radiator flush would help.

Hope this helps...

yea if theres stuff in the oil its most likely anti-freeze in most cases its a blown head gasket i would get that fixed and than change the oil agian

How many QTS of oil I will need for a 08 model 3.5 engine

this is caused by a blown cylinder head gasket.

you more than likely have a blown head gasket ...

The reason that your anti-freeze is gelling in your rad is that the mixture of anti-freeze and water is too weak. this could be because of old anti-freeze(same as oil,it deteriorates over time, usually 2 to 5 years), or there could just be too much water added. I would suggest a cooling system flush, and re-fill with a new 50/50 mixture of water and anti-freeze.