I have a 95E300 with 254K. Normally I change the oil every 3K but due to schedule missed it and went to 4k. Did an an oil and filter change last night with Delvac 15w/40, just under 2 gallons.After tightening the pan bolt and starting it to check for leaks, I found no leaks and parked the car for the night. Checked the oil this morning and had a full dipstick. The lifters on this car are beginning to make the ticking noise associated with going bad, and so I picked up a pint can of Lubro Moly MOS2, molydenum disulphide, and put in just under a quarter of the can this morning before going to work, letting it settle for 45 minutes before starting it.

After leaving, a family member called and said my car had left a small pool of oil and a trail of oil on the ground as I drove away. Luckily I was a mile from home, but no low oil light had yet come on. After I turned around, about a half mile from home the light came on. I made it back and shut the engine down, dropped the front engine insulation cover and found oil covering everything from the back of the pan by the transmission going back. It looks like the rear main seal is blown out. No oil coming from the pan bolt or topside that I can see yet, still in the process of trying to determine where the leaks are coming from and how much damage I caused to my engine. Drained some oil out so thankfully it wasn't bone dry, although the dipstick registered empty.

My initial hunch is that the additive weakened an old seal or seals and caused the leak. Any thoughts and suggestions appreciated.

I'm not a big fan of oil additives because I believe they can change the oil's original chemical makeup. I had lifter noise in the 560 and switched to Chevron DELO 400LE because it has ZDDP added. The engine quieted right down so I now know that the car requires an oil with ZDDP.

The best way to check for oil leaks is to degrease the engine completely. I'm in the same boat on the 300D as the engine is greasy thus I'm looking for someone to steam clean the engine as I believe steam cleaning is the safest way to clean a motor. Otherwise, spray the motor with a a good degreaser like Purple Power and let it sit for 30 minutes. Take some shop rags and wipe off the bottom of the engine as best you can. I don't like spraying engines with water due to the possibility of contamination of electrical components, etc.

Then, if weather permits place the car outdoors on a bright sunny day and with the hood up and a bright work light in hand, start the engine. Have someone rev the engine slightly while you look both topside and underneath the car for the source of the leak. It might be something simple like a bad oil pan gasket or something more serious.

One thing for sure, anytime an oil light/oil pressure gauge reads low or zero it is best to shut the engine down immediately and call a tow truck.

My initial hunch is that you didn't get the oil filter lid on securely.

Conducting an experiment in which multiple variables are changed simultaneously makes it easy to draw inappropriate conclusions. It is hard to understand how an anti-scuffing agent would cure "lifter noise," which is typically a hydraulic issue.

I wouldn't jump to the conclusion of a bad rear main. In fact, I've never heard of one failing that quickly and that completely. I'd look elsewhere. I don't know what the filter assembly is like on that vehicle but I'd look for a failure in the filter to engine connection or filter cover leak.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

agree with TF on a logical basis. Buy some UV additive, fill er up and get your black light out. You'll need to have everything really clean before you do this. I suspect your oil filter stand btw, because you couldn't blow that much out a rear main unless the crank ground itself .200" under somehow.

I still add a dollup of ZDDP additive to the oil, especially if its synth, which is what we run in the winter. The only saving grace is I ASSUME the beehive valvesprings dont have much pressure. We also run "wingas" in the warm months, bioD out of chicken wing fryer oil. Have read that bioD attacks the anti-wear package ( ZDDP et al) in oil, but oil analysis hasnt proved it yet so it may be a feed stock issue.

But VW TDI are eating fuel pump lobes due to lack of ZDDP in modern low emmissions oil.

BTW, VERY IMPORTANT ESPECIALLY AFTER AN OIL INCIDENT!!!!!!!!

If you havent changed out the vacuum pump. CALL PHIL IMMEDIATELY!

Bend over and accept the $450 reaming without neary a whimper, becuase I will tell you THIS IS HOW I LOST MY 95 606 ENIGINE!

Foolazz leaves the oil fill cap off, loses a bunch of oil and months later, without warning, the VP goes. Now it had done a little damage to the ramps on the drive gear, but I "polished" it and slapped the , then $365 part on. WRONG!

Yeah, these guys know what happened next. when you pull the oil canister cap off and a TABLESPOON of metal shavings awaits you, that's a $5000 HIT ASSUMING the IP could be saved.

I am no longer a soldier, but I will say, " Sir DO NOT THINK about what I said, just DO IT, and DO IT NOW!!!" There is a high probability another collateral incident will now occur, and its is an expensive one that might destroy the engine.

REPLACE THE VACUUM PUMP IMMEDIATELY!!! The engine is at the required 250K anyhow.

My bad, it is a hydraulic compensator issue.....all I know is prior to the Chevron 400 LE, mucho tick tick tick, after, NONE.

My vote is the old o-ring is still on the filter lid, or it fell out when installing the lid.
VERY common on these cars with the oil filter canister, to have the lid o-ring slide out during install, and result in a nice spray of oil down the back of the motor..

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Yeah, I'm betting on that too. To lose that much oil that fast it has to be coming from somewhere pressurized. If it's not the oil filter, check the oil cooler hoses (if equipped) and oil pressure sender. I once lost three quarts of oil in only 30 miles from a bad oil pressure warning light switch on a VW.

__________________
1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

Thanks for all the input. I would have stopped but had my 7 y/o niece in the car taking her to school for a 60 mile round trip, in the rain with heavy traffic. I feel lucky to have turned around in time as I was close to home. Yes I could have called a tow, then wait for 2 hours on AAA which is the average ETA here, but took the chance on getting the child back to home safe outside of traffic. As of now out of a four car family we're down to one after this incident, with two others breaking down within a week of each other in the past two weeks. Frankly if the engine has bit the dust, considering the $13K total investment I have in it, I'll total it and buy another used car, simply too much money and effort to fix/replace it.

I got the intake, wiring harness and non-functioning cruise control unit out, and drained about a gallon of oil and pulled the filter. Looks like in my haste last evening I left the o-ring off the oil filter housing, but that wasn't the main culprit; it was the seal between the oil filter housing and block. Oil is standing on the edge of the block below the housing. Haven't checked for metal shavings yet in the drain pan or filter but will now. I also have a new spare vacuum supply pump on the shelf, so I'll pull that to check for damage. I changed it at 180k when I bought the car 5 years ago, so it has a little life left in it, but now I'll assume the worst and change it provided everything else looks ok. If not I guess its back to shopping for another car, couldn't come at a worse time.

I'm going to assume that the additive caused the seal to shrink, because this is the first time this has ever occurred on this car. I started and ran it last night before putting in additive this morning and had no leaks. Checked again this AM before adding the Mos2, oil level was full with no leaks. As for the hydraulic lifter issue, yes I'm aware that they have to be replaced, just thought I might buy some time and help the engine out a bit. I have the FSM for W124 series, wish me luck.

Before you go to the trouble of taking apart the housing to replace that seal, clean up the mess, reassemble the filter canister properly with an O-ring, and check for leaks again. My guess is your block-to-housing seal is fine and you're seeing oil that ran down the housing and puddled there. Oil has a fair amount of surface tension and tends to follow surfaces downhill instead of dripping straight down.

The lesson here is always let the engine run for a minute or two and look for leaks after an oil change, before declaring the job finished.

__________________
1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

I have $10,000 that says that the o-ring was the one and only culprit. With the filter lid not sealed, there won't be enough pressure for the housing-to-block gasket to leak if it wanted to.

If you had run the engine long enough to fill up the empty oil filter housing, the oil level on the dipstick should have dropped. Obviously, the filter housing won't leak from the lid until it is substantially filled.

where are you located?
it's a shame you took all that apart for an oil filter lid o-ring, but lesson learned.
I hope you didn't damage your engine with low oil pressure, but if you did, there are plenty of vultures, I mean members here that will take it off your hands!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

X2 without the $10k, Mr Romney.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

There was oil circulating the whole time in your engine. I'd just put the o-ring in place, fill it with oil and start driving it. Not a big deal.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Problem is, the bulk of the "circulation" was occurring only between the pump and the filter housing. With the lid not sealed, oil pressure downstream from the filter would be reduced at best, all but eliminated at worst.

That said, I agree that the situation could have been a non-event. Also could not be. The loss of oil pressure could have been a bigger issue than the loss of the oil itself.