shoot_da_breeze

I have a S500, I had an oil change before an the oil was 5w40 (dealer), to save some money and get a look under my car, I put it on a lift and did it myself. I put 0w40 in it, and about 1 month later, (last Tuesday to be exact) I get a message on the dash oil low, add 1 litre. I add it, and drive home. I wake up the next morning my driveway is a mess about a 2ft by 6 ft oil spot. I removed all the panels, clean up as much as I can, and refill with oil. The oil is leaking from behind the alternator. Whats causing that? I was thinking of driving it to the dealer but if its simple I'll fix it myself. btw the oil leak is bad. But only leaks when the car is on. Plus, I hear this air noise when the engine is on. Like theres a bad air line. PS. I dont have airmatic anymore. I have the coil conversion.

tusabes

a leak that bad is usually oil pressure sensor, or busted oil filter or drain plug

S600Keith

I would double check the drain plug and make sure it is tight and not cross-threaded or anything. My son changed his oil and bent in the side of his filter and got a leak from that one. Worth a look.

shoot_da_breeze

The first thing I checked was the drain plug. Its tight and not leaking. I'm going to check the oil filter but i doubt its installed wrong or its busted because i replaced with oem.... I used everything from the dealer.


I was thinking its the dipstick o-ring, or the rear main seal. but where should i check for those items? I have read in other posts for the m113 engine and those were their problems. Because its leaking behind the alternator.

Also where is the oil pressure sensor?

tusabes

dont know where it is, but know its a source of leaks...had a jag that almost lost all its oil from a bad sensor

https://mbworld.org/forums/s-class-w...re-sensor.html

shoot_da_breeze

Can anybody tell me the location of the oil pressure sensor? is it a easy replacement? part price? I dont mind trial and error process. as long as parts aren't $300 a piece. If just under 100 its cool lol.

shoot_da_breeze

Ok i ordered the new oil level sensor, anybody know where the part placement is?

Quadcammer

should be front passenger side of the bottom of the oil pan. Look for a triangle shaped plastic piece.

s5benzo

oliver is correct . behind alternator next to dipstick tube. it has 3 wire connector , replacement calls for 2 hrs book time, seems like bottom oil pan has to be removed. hopefully that solves your problem. goodluck

shoot_da_breeze

Sorry I've been away for so long, I busted open the oil pan, and swapped out the sensor. It didn't change anything. The leak got smaller, its about the amount of a pee stream, but not so pressurized lol. I had a friend think say he thought it was the rear main seal. but thats located right before the transmission, and it is not leaking that far back. Any other recommendations?

AH1W-COBRA

check your entire PCV system. if the system was plugged and i cant imagine how but the pressure would have to be released somewhere. if the bottom of the dipstick tube was the weakest seal than it could pump/blow oil out at that location. should not leak however when not running. i can actually tell if the wife has done any serious high rpm passing by checking the dipstick. anything over 4000rpm wil cause crankcase pressure to lift the dipstick just slightly. the only reason i mention this is because you said you are noticing a hissing sound.

shoot_da_breeze

How do yu change the dip stick o ring. I herd it was easy but how do you do it? I got it from the dealer and the oil level sensor from them. But never put the seal on. Any help would be appreciated