Ah, yes. Actually I am well aware of this- but I figured the post title would draw the ire of- and ideally thus, the most help from members!

Sorry to anyone really looking forward to tearing in to a wholly useless idiot.

Anyhow, a friend of mine has a 2018 c-class sedan. Not my most favorite Benz ever, but then I favor the old diesel models…early 80s were a big, clunky dreamboat…but I digress.

Said friend loaned hers to another acquaintance of ours to pick me up from a late party the other night, and while we were driving along, smooth highway, there was an alarming crunch beneath the car, despite not having hit anything, which turned out to be the oilpan parting company with the vehicle. Oh **** is right! It was such a brief noise we assumed we had run over some road shrapnel of some variety, and consulted the dash/instrument console to be sure nothing was going haywire there. Not a peep or blink, nothing. So we proceeded, and about 5-10 minutes later, the vehicle began to slow and was completely non-responsive to the acceleration attempts, like it was not getting any fuel. We had just stopped and topped up the tank before heading home, so that made no sense, and within 30 seconds of that happening, it coasted to a complete stop and shut off. My friend tried to re-start it, naturally, but it didn’t budge. Didn’t make any noise or smoke or anything. Still no warning indicators or anything of any kind.

As we were sort of out in the middle of nowhere, people around those parts of Eastern TN are kind enough to stop for damsels in distress, and we caught a ride the remaining few miles home, leaving the poor Mercedes beside the road. We had it towed in to the mechanic, who called the following morning to say that the engine had seized. If so, that was the quietest engine death in history.

So, yes, engines DO need oil! My question is this: why did the oil pressure failure not register as some variety of fault code? And is it possible that the car had some variety of fail-safe killswitch built in, that needs to be cleared prior to restarting? I know that nearly all European luxury cars tend to skew on the picky side for requiring dealership/brand-specific diagnostic equips and whatnot- is it possible that the idiot to whom they took it (not many choices around where this happened as far as tow trucks go…and he once “loaned” parts off of my Volvo to another customer- long story lol) just doesn’t have the knowledge or the set up necessary to fix it?

Or am I just hoping that this poor man is even dumber and more ill-equipped than he, in fact, truly is?

 

First, that sux. Second, Mercedes does NOT have an oil pressure sensor though I'm guessing (hoping) it does have an oil level sensor (at least my 2004 SL500 did). Still, you should have gotten some kind of warning.

You said the oil pan fell off? How did that happen?

 

Here is a picture of the instrument cluster for my 2014 C-Class. Notice that there are NO warning lamps for anything oil?

 

Interesting thread. Seems to me an oil pressure warning would be basic. I can't find an oil pressure icon at ON, but a lot of the warnings have been moved to the center display so I wouldn't be surprised.



That said I can't seem to find a photo of a low pressure warning in the center display, but I do see the low oil warning mentioned above which I've also personally seen.



Playing Devil's Advocate, any chance the garage is fibbing to get you to sign off on a much more expensive job? Wouldn't be the first time a mechanic lied about a diagnosis.

 

As I said, my 2004 SL500 had an oil level sensor as that was the only way to check the oil. (You could get a special dipstick, but that was usually reserved for mechanics.). However, since it appears Mercedes has moved away from such nonsense, I see no oil sensors at all other than temperature.

 

Well if it does not have oil pressure indication to you, it probably have it under the "Engine Light" coming up thing. It would be real stupid for a manufacturer producing an expensive car where the system has no clue about oil pressure to preserve the engine. Who would want to buy such a car-?
You need further investigation as to whats really went on. I would assume flying conrods or broken crankshaft could up set an oilpan for it to leave the engine.

According to the oilpan I assume your engine is in pieces internally and it was shown to you, but without engine light and shut off-?

 

Nope. You should do your research. There are quite a few posts discussing this. There is no oil pressure sensor on Mercedes engines of this and similar model generations. If you check the procedure in the WIS for how to test oil pressure, the instructions are to attach an external oil pressure gauge at the oil filter housing. If you can show otherwise, please share.

And everyone agrees that it is "real stupid."

 

For your reading pleasure...

https://mbworld.org/forums/mercedes-...hlight=p06da00

https://mbworld.org/forums/w212-amg/...hlight=p06da00

Or, search threads for "P06DA00".

 

You know with all the engineering development over the years, one would think that engines would have an electric oilpump for startup so engine never turns without full oil pressure by this time of engineering excellence, I mean a 100 years had passed and huge claims are made on a daily basis...........

 

That would be cool. I wonder what risks there are to depending on an electrical connection to operate an oil pump.

 

I don't mean electric pump all the way, START---just seconds before startup and RUN then mechanical pump take over just like before, if electric pump fail, no big deal, but a real big deal over time when it mostly works. If mechanical pump fail, electric pump can take over with alarm warning to fix mechanical pump.

The risk would be how its implemented not to leave an open cct ever with no oil pressure to mechanical pump which will be a big fail..

 

I remember on my older VWs and Audis that when you opened the driver's door, the fuel pump would activate so that there would be no problem on start. (Newer ones probably do the same.) The same approach could be taken with an electric oil pump.