240D finding oil leak - PeachParts Mercedes-Benz Forum

arcticathlon · #1 04-18-2007, 11:24 PM

so i am either loosing oil by burning it or via loss by drippage. after about 1 month of driving, the oil pressure gauge has dropped to 1 bar. instantly i pulled over and shut off the car and refilled it Rotella T oil i had in the trunk. she took 4 quarts to get it to show on the dip stick. i check the oil at every diesel fillup, but i drove it very little, often and ran out before my next fillup. the underside of the engine is very dirty, but most of moist and fresh oil appears to come from the front of the engine. I dont know the official name of it, but the main shaft that all the belts connect to, right above and around it is where i think it is leaking. is there a seal of some type that could be leaking?

i can also see lots of smoke while driving at night with a car close behind me, and my wife passed me because she said it stunk too bad to follow me.

the engine has 711k on it, so it is worn that is for sure, but drives fine. i am not sure of the history of the engine, as i did not get anything from the previous owner. the engine is louder than my 300D, and has some odd clacking i right at startup before the oil pressure gauge has pegged at 3 bar. I am also sure that i need to replace the motor mounts, as it wiggles around in the engine compartment.

as far as blowby the oil cap dances around (teakettle like) and falls off after about 5 seconds. my 300D barely moves, so i consider it pretty decent blowby on the 240D's part.

my main concern is oil leak. i dont want to run it out, or have someone else drive it to death. i think i will change the oil pan gasket as it is old and looks swollen/soaked.

took some pictures, but not sure how well they show the oil. it was hard to get the camera to cover the area that i was meaning to show.

arcticathlon · #2 04-18-2007, 11:33 PM

so i just looked at my oil filter and it is soaked in oil, i mean soaked. you can see the difference in one of the shots. the bottom of the air filter housing has some holes in it, where it drains out. i took some pictures of the exhaust manifold below it and it is covered with oil. this looks to be the culprit, i can definitely see me loosing my oil this way, but how does that much oil get in my air filter, just strong blowby?

thoughts?

Cervan · #3 04-18-2007, 11:40 PM

that much blow by can cause diesel overrun i suggest you figure out this problem before your engine explodes. blow by is caused by air getting past the rings or the valves no other places. so if your engine has that many miles on it i would think that needs a rebuild.

arcticathlon · #4 04-18-2007, 11:44 PM

i understand what blowby is but could you explain what "diesel overrun" is? do you mean a runaway engine? what would cause a overrun and is a rebuild the only solution?

stcbenz83 · #5 04-18-2007, 11:51 PM

i think by "over-run" he ment a run away diesel. were oil acts as a fuel and u have no way of turning the engine off, or regulating speeds. so basically the engine is running at an ungodly RPM and blows the engine. How long has this problem been accoring?

also is that 711K on the original Engine with no rebuild?

Cervan · #6 04-18-2007, 11:52 PM

diesel overrun is when too much fuel enters the combustion chamber or as mechanics call it "unmetered fuel" meaning that so much fuel is going into the chamber that it is burning instead of the fuel that is supposed to be injected from the injector pump. so if you have a massive ammount of blowby and it all gathers up then dumps into the intake you will have oil heading straight for the cylinders and the oil will burn and nothing can stop it then except for a 20 pound hal canister.

for your second question there is nothing you can do about blowby if its coming from your rings. you can try all the voodoo out there but in the long run if its this bad there is no magic trick to make this go away without rebuilding the engine.

JimmyL · #7 04-19-2007, 01:26 AM

Is that the 240D that was for sale in the DFW are a couple of years ago, or am I thinking of another one????

whunter · #8 04-19-2007, 03:16 AM

All diesel owners should read this thread.

Run away diesel, why does it happen?
http://www.peachparts.com/shopforum/showthread.php?t=101404

Have a great day.

arcticathlon · #9 04-19-2007, 07:14 AM

i bought this one from a guy in dallas last year, so ya this is probably the one. what do you know about it?

Bruce Kennedy · #10 04-19-2007, 08:43 AM

Alot of the 240's vaccum pumps vent into the air cleaner. If the diaphram on the vaccum pump gets a hole in it, oil gets sucked into the air cleaner and they will smoke like hell.

arcticathlon · #11 04-19-2007, 11:00 AM

when i got it the vacuum pump was messed up, and i ended up having to replaced the diaphram. so ya oil got in there, but i also replaced the oil filter, so it should not be as oily as it is now. i mean the car drives great, and i did not pay much for it. i bought it as a parts car or car when i am working on my 300D. i also wanted it so i can possibly convert my 300D to a manual, but i will drive the car until it dies and then decide if i want to rebuild it.

barry123400 · #12 04-19-2007, 11:52 AM

If you upgrade to a straight 40 weight oil it willl reduce the blowby substantially. The weather is warming up now so car should start okay. Just one way to buy more time generally. Not really voodoo.

arcticathlon · #13 04-19-2007, 12:03 PM

what oil would that be then, i want to make sure that it meets the diesel standards. i just use RotellaT 15W-40 in it right now, what do you mean with straight 40?

vstech · #14 04-19-2007, 12:36 PM

other than the VP I cannot figure out how oil is getting into the AIR FILTER. on the NA cars, isn't the PCV hose dumping into the intake below the air filter?
John

Cervan · #15 04-19-2007, 04:14 PM

if the timing is off then it would be injecting fuel before the intake valve opens... meaning that it blows air back out the intake... but thats a stretch