willc55

So I just had my oil changed by a local independent shop, and I have a few questions. While they were draining the oil out of the pan they only removed one of the plugs... is this a problem? I was standing right next to the guy and asked whether or not there were 2 drain plugs and he said that their weren't. After doing a search on the forum I have turned up some conflicting information on this, some people saying to remove both plugs, others saying they just remove one.

So they drained the oil, changed the filter, and replaced the oil with Mobil 1 0w-40 (after I had to convince them not to use 5w-30). However, when I got back into the car and checked the oil level through the computer, it said "Reduce Oil Level". I didn't get any error messages or anything though. I brought this to the attention of the mechanic and he said that it was fine, and that if it still reads Reduce Oil Level tomorrow morning I should bring the car back in and they'll take some out.

I drove maybe 2 miles from the shop back to my apartment, and haven't driven since. Am I risking serious engine damage, or is it fine like the mechanic said? They didn't measure how much oil drained out, so I have no idea if just using one plug got all the oil out, and now I'm concerned.

Thanks for your help.

Dingleberry

Two drain plugs. Your car is overfilled by at least a quart of oil.

link146

In short, yes you are risking serious damage to your vehicle by being overfilled. Of course, I do not know by how much your vehicle is overfilled so I must assume the worst. At the worst, you can blow your motor...nuff said. Pump out a half quart at a time and check until level is satisfactory.

MarcusF

As others have said, it sounds like you have too much. Some cars (not C55’s, but cars in general) have single plug pans. With those cars, all the oil can be drained using that single plug. Cars with two plug pans require both plugs be removed to drain all the oil from the sump. It sounds like they didn’t drain it all, but added oil as if they did (for example: removed 6.5 quarts and added 8). This is confirmed by your oil level sensor.

As for damage, I doubt you’ve done any damage at this point, but I have no idea how many quarts a C55 pan will hold before things start going bad. If I were you, I’d (1) reduce the level as soon as possible, and (2) change mechanics.

This is why you don’t want to overfill a car with oil – if the pan is so overfull of oil, that the crankshaft hits the oil as it rotates, the oil will foam. Oil pumps are designed to pump oil in a liquid state. If they pump foam, metal parts that are supposed to have a layer of oil between them, will have nothing between them, and very expensive parts will wear rapidly. Also, if the oil level is higher than the oil pan gasket, the pan gasket will leak. If it’s higher than either the front or rear seal, that seal will leak.

No need to panic at this stage, but you may want to take it to the dealer, who will extract the excess oil with a pump. If you’re in SoCal, specifically the SCV or SFV, I could come by and pump it out. Pumping it out takes about 30 seconds.

link146

Additionally, and I think this goes without saying, easy on the throttle if you must drive the vehicle while overfilled. Also be aware of the engine temp because usually an overfilled engine will tend to run hot.

Dingleberry

Changing the oil on MB's is so easy. I don't see why people don't just do it themselves... you don't even have to get underneath the car! Just extract from the top and change the filter which is also on top.

willc55

Thanks for the responses, if there is anyone who has the ability to pump out some oil in the NYC area, and would be willing to swing by to help me out I would much appreciate it. I'm nervous about even driving the car back to the shop now.

willc55

Also, before the oil change, I checked the level and it said "Add 1.5 qts". It had been a little over 5k since my last oil change, what effect if any would this have on how much the car is overfilled?

buffyclk500

Just putting in my imput in but I did 3 Benz that the same thing happen 2 them and we had 2 do new rear Main seal it cost nothing us it was like 15 in parts but around 1000 out the door and all because they put 2 much oil in it and drove around and it break the rear seal and oil was driping out

willc55

Ok, now I'm a little confused, because I just checked the level again and it said "Oil level OK"

Are you supposed to test the level when the engine is cold or hot?

moosejaw

dude
i jut changed the oil last week
there are two drain plugs

get your oil changed somewhere else.
the place you took it to. they do not know what they are doing.

do a search to see what happened when too much oil was put in

Dingleberry

i just did a search, apparently it causes global warming and black holes!

i thought black holes could only be created if you tried to divide by zero!

willc55

Could someone tell me if you are supposed to check the oil level when the engine is hot or cold? I'm kinda freaking out about this, and like I said, when I just checked it cold it said the level was OK, so I don't know what to do.

Dingleberry

generally hot. oil takes up more volume as it heats up, and less volume as it cools. i suspect that your car is just barely overfilled, causing the computer to complain as your oil heats up and you break the threshold for maximum level. sounds like you are about a half a quart overfilled, not a MAJOR issue, but you should swing by and have them drain out half of a quart

MarcusF

My owners manual states –

Check oil level approximately 5 minutes after stopping
the engine, allowing for the oil to return to the oil pan.

You may want to check your owners manual. My owners manual allows for zero circumstances where I should see a message that says the engine has too much oil in it. My manual also says -

Do not overfill the engine. Excessive oil must be drained
or siphoned. It could cause damage to engine and
catalytic converter not covered by the Mercedes-Benz
Limited Warranty.

I recommend that you give serious thought to taking the car to either a Mercedes-Benz dealer, or a mechanic who can extract 1 or more quarts of oil from your engine. The shop that changed your oil has not demonstrated a great deal of competence in this area. Although they caused the problem, I would not recommend using their services to correct this problem.

willc55

I put the car into Dyno Mode, and the oil level read 9.0l, I think that I will do as you suggested and have a different, competent mechanic extract a half a quart, although for now I am not quite as nervous about it, as it seems that the oil is in fact BARELY overfilled.

Dingleberry

Damn, my prediction was pretty close

advans

Will, the oil will go back to 8.9qt which is what we need in the C55s, in a few days, especially if you drive your car hard.

If this still comes up, come by my shop. we'll take care of it.

moosejaw

why wouls you have them extract half a qrt when they didnt drain the whole case to begin with

You still have old oil in there.
Print out this thread and showit to that dipsh*t mechanic.

1Lop2K5C

9L is a little overfill, you went over the half quart threshold. 9L = 9.51qt. Your dyno mode level should be around 8.5L. I always play it safe and leave mine at around ~8.2-8.4 which should be at 162-164mm on the convetional oil dip stick.

TemjinX2

honestly i would just spend the money on getting a pump extractor for $70-100. You can find them on ebay or amazon for that much. Its definately worth the investment. Doing oil changes on c32's are probably one of the easiest and cleanest out of any car i worked on in the past.