Dear Mr. Bible,( and all others reading this )

sorry to trouble you, but I have a technical question for you. You seem to be quite knowledgeable, so I am seeking your insight here.

I have a 1993 600SEL sedan with 84k miles on it. The car is in great cosmetical shape, it was garaged and has been dealer maintained by Plaza up in St. Louis. I'm a small one man operator who buys, repairs (light repair work), and sells old Mercedes on ebay for a living in Memphis,Tn.

Anyway, I bought this 600SEL at a local auction, and the only reason I bought it was due to its stunning overall cosmetic condition. I tested the car at the auction and it ran great, smooth idle, and no check engine light.

After I bought the car @ auction, I noticed it was smoking after running for about 30-40 minutes on the highway. Later it stopped smoking as abruptly as it started. The smoke was whitish/blueish and was very acrid and potent. Made your eyes sort of burn.

I continued to drive the car and it continued to intermittantly smoke. The smoking never occured when cold (which is why it appeared fine at the auction). The smoking did set a check engine light, which revealed the following-

009- Transmission overload protection switch DI2

013 -CMP- sensor signal DM

034- O2s DM

017- Can-data exchange DM

ADS-

008 - Solenoid valve RA Y53Y1

009 - solenoid valve Y53Y2

Group LH1

008 - CMP sensor signal L5/3 Not recognized

Group LH2 SFI

02102SG3\3 - Signal Open Circuit

022- o2s Heater G3\3 02 heater open circuit

The smoking would start after 30 minutes or so, and then would subside if the car was left to idle. I pulled all of the spark plugs and noticed they were perfect! I checked the crankcase oil and it was VERY clean and showed no signs of contamination. I checked the coolant reservoir and it also showed no signs of contamination.

The next time the car acted up, I pulled over and I rasied the hood while the car was running. I looked at the engine quite a bit and I noticed that while the car was running that one of the vaccum lines had fluid in it.
The clear / Red stripe vaccum line running to the ignition control module on the driver's inner fender had oily fluid "pulsing" through the line towards the ingnition control module. I traced the line back to the intake and it was connected to the right intake manifold (passenger side). I then carefully removed the intake manifold(s) and found what I believe to be clean crankcase oil pooled in the intake wells. Most prominently in the right side of the intake. It looks like oil from the crankcase, but I suppose it could also be hyraulic fluid, but my guess is oil.

Something is contaminating my intake and then being atomized and burned. The car is smoking like a freight train when it is burning whatever is in my intake.

I read the MB model year update and looked at the sections regarding M120 crankase ventilation , and looked at the oil seperator and the dampner, but they didn't have any traces of oil in them. I have been suspicious that the seperator was failing, but see no signs of oil pooling anywhere in the circuit.

The EGR on the right side was all gummed up and looked like it was clogged with caked oil. I cleaned the passage which was nearly fully obstructed.

I have a copy of WIS on my computer , but found nothing of note regarding the M120.

I also noted that there was an aftermarket muffler shop type CAT on the left side of the engine that had been welded on.

Do you, (or anyone else reading this) have any ideas for me?


Kind Regards,

Herbert Phillips (Herbert on Ebay)
800-310-8767