Found my oil leak! Now I need info

[rman]

okay, got the M112 280 motor

Cleaned it up yesterday, and checked it out today. There is a small "cap" under the driver's side head, somewhat central. It is held on by 2 reverse-torx type bolts.

I have heard before that it is common to leak from there, and that it is an o-ring.

Just wondering
-What exactly is this?
-Should I wait till next oil change to repair it, so that the motor is drained?
-Anyone else have this problem?

Thanks in advance....

[irieite]

Rman,

I have the same engine, but I have not yet had or heard of that problem. How many miles are you at?

As far as whether you should change it with the oil drained, you should be ok changing it with oil in the engine, so long it is located above the oil pan. When the engine is not running, most all of the oil returns and remains in the oil pan. Even if you drian the oil, a little bit will remain in certain areas. However, if you're due for an oil change soon, might as well of take care of both chores at the same time.

For future refrence, please let us know what you find out/do.

[1995c280]

that is the oil pressure port. very easy to replace. first take out the allen bolt in the middle, then the 2 torx bolts. there is a flat rubber gasket (not o-ring) behind the plate. very cheap parts from the dealer (really, some things for benz's are actually cheap, LOL). you get a new allen bolt with copper seal ring, plate and rubber seal with the kit. these are known to leak all the time so the new seal with be slightly re-designed. no need to drain oil or anything to replace this...it's an easy 5 minute job!

when tightening the torx bolts just use a 1/4 inch rachet and not to tight with them, just a 1/4 of a turn more after it stops!!!!!! you can give a good tug on the allen bolt though.

Jason

[rman]

thanks for the responses.

I'll get to it when I have some time...hmmm....maybe while at work when I have some down time since MB is 2 blocks away and we're always slow for our last hour or so.

I'll take a pic tomorrow just to verify that we are on the same page!

[1995c280]

Originally posted by rman
thanks for the responses.

I'll get to it when I have some time...hmmm....maybe while at work when I have some down time since MB is 2 blocks away and we're always slow for our last hour or so.

I'll take a pic tomorrow just to verify that we are on the same page!

yeah just buy the parts from the dealer and tell them you want the kit to re-seal the oil pressure port and make sure they give you everything i listed (should be 4 items). and then do it yourself cuz we charge 1 hour for the job and like i said it takes no more than 5 minutes (gotta love flat-rate).

Jason

[irieite]

Good future info for me. Thanks guys! :bunny:

[MBHustla858]

you don't need to take the allen bolt out........ thats un necessary. just take the two torx out and put a new square gasket on it and put it back together, 10-12 mins max

[rman]

ok.....so i went to the dealer and got a replacement set.

1 new oil gasket
1 new allen bolt
1 new allen bolt seal (crush washer)
1 new inspection plate (the plate itself)

-It looks totally different than the one i took off. The hump on the outside of the plate is much taller, meaning the allen bolt protrudes less on the inside
-The original one uses a plastic/rubber square o-ring type thing, the new one used a flat rubber piece with 2 holes in it.
-The original plate has a raised portion on the inside, where the allen bolt comes thru, the new one is flat, hence the flat rubber seal.

So I install the new one and it leaks. Worse than ever. Enough for me to smell oil at red lights, smoke, and leave a small 8x8" puddle.

I installed the new one hopefully it'll go back to 1 tiny drop a day or maybe less by some miracle. I'm going back to the dealer tomorrow to strangle him and then find out WTF is going on.

[rman]

hmmmm......

1995c280 sounds like you are using the one that is not working for me, the flat plate with the flat rubber gasket.

Could I have installed the gasket wrong? I also noticed that the size of the gasket is shorter (lengthwise) than the square-o-ring that I originally had in there.

[1995c280]

Originally posted by rman
hmmmm......

1995c280 sounds like you are using the one that is not working for me, the flat plate with the flat rubber gasket.

Could I have installed the gasket wrong? I also noticed that the size of the gasket is shorter (lengthwise) than the square-o-ring that I originally had in there.

you have the right set. the new re-designed gasket has two slits in it. maybe the rubber rectangular gasket is installed in reverse if you look on the sides of the gasket, the round edges should go to the plate side and the flat side goin to the engine. it this how you placed the gasket? are the torx bolts tight enough. this is surprising to me cuz i have done this job countless times at work and have never had one leak after!

the length that the new plate protrudes has nothing to do with anything. the allen bolt does nothing but stop oil from leaking out because it's where you hook up the gauge when testing oil pressure.

Jason

[rman]

my new flat rubber gasket has 2 holes in it, and one slit in the middle.

The slit sits in a round recessed area, I installed the gasket with the recess towards the plate (to "accomodate" the allen bolt.)

I'll give it another shot tomorrow at work if when we slow down. I want to put it on the lift and clean out the splash guard and everything else under there since it's filled with oil now.

[1995c280]

Originally posted by rman
ok.....so i went to the dealer and got a replacement set.

1 new oil gasket
1 new allen bolt
1 new allen bolt seal (crush washer)
1 new inspection plate (the plate itself)

-It looks totally different than the one i took off. The hump on the outside of the plate is much taller, meaning the allen bolt protrudes less on the inside
-The original one uses a plastic/rubber square o-ring type thing, the new one used a flat rubber piece with 2 holes in it.
-The original plate has a raised portion on the inside, where the allen bolt comes thru, the new one is flat, hence the flat rubber seal.

So I install the new one and it leaks. Worse than ever. Enough for me to smell oil at red lights, smoke, and leave a small 8x8" puddle.

I installed the new one hopefully it'll go back to 1 tiny drop a day or maybe less by some miracle. I'm going back to the dealer tomorrow to strangle him and then find out WTF is going on.

when you took the old one off, there is oil that will slightly drip down the engine for a while. did you clean the entire front cover with brake clean to get rid of it. maybe that is why your smelling the oil burning. or do you physically see it leaking?

Jason

[rman]

yeah i cleaned the shit out of it so that I could detect any new leaks.

i'll give it another go today and see what happens....

[rman]

i think it's fixed.

i'll have to keep a close eye on it though

[1995c280]

Originally posted by rman
i think it's fixed.

i'll have to keep a close eye on it though

glad to hear it's fixed. let us know if everything turned out ok!

Jason

[rman]

still leaking. put a dye in it yesterday and took a look today. very difficult to see, but from underneath you can see it looks like it's coming from the tensioner.

any ideas? this is the m112 v6 BTW...

[1995c280]

ok...we know that you can work on cars by the way you post and you do own repairs but i am wondering if the torx bolts are maybe too tight and it stripped the threads when re-installing the plate and seal. it's only aluminum. are you sure the bolts are ok?

like i said...i've done this repair soo many time and never had 1 come back leaking so something must have went wrong down the line!

Jason

[rman]

thanks to you, jason, the oil pressure port is not leaking. the seal was on backwards, and after examening it, I realized I had made a stupid error.

yesterday i got under to inspect my ball joints and tie rods (i hear a popping sound in the front left when turning, or sometimes on speed bumps) and i noticed the splash guard had oil on it again.

It was coming from the right side of the motor, and i was fearing head gasket.

I put a dye in the oil and re-inspected today.

It seems to be leaking from the tensioner pulley, and can only be seen from underneath the car, not under the hood. Actually, it's seems to be coming from where the tensioner pulley arm mounts to the block. Is there a seal behind there that might be leaking?

[MBHustla858]

could be residule from R&R in the square gasket.... or it could be ur sub pan... those do leak from time to time clean it off w/ brake cleaner and compressed air.... are you using a uv light to look for the dye?

[1995c280]

Originally posted by rman
thanks to you, jason, the oil pressure port is not leaking. the seal was on backwards, and after examening it, I realized I had made a stupid error.

yesterday i got under to inspect my ball joints and tie rods (i hear a popping sound in the front left when turning, or sometimes on speed bumps) and i noticed the splash guard had oil on it again.

It was coming from the right side of the motor, and i was fearing head gasket.

I put a dye in the oil and re-inspected today.

It seems to be leaking from the tensioner pulley, and can only be seen from underneath the car, not under the hood. Actually, it's seems to be coming from where the tensioner pulley arm mounts to the block. Is there a seal behind there that might be leaking?

like MBHustla858 had said...when you change the oil pressure port seal - oil runs down the engine quickly to the splash guard. i would take out the splash guard and clean it completely and then take a hose and spray the entire front of the engine and brake clean the top and sides of the engine. then reinspect. could be oil filler neck/cap, valve covers, upper/lower oil pan, front crank seal. there is alot of possibilities when it comes to oil leaks especially with the 112 and 113 engines!

there is no oil that can leak directly at the tensioner but there is a huge 0-ring rubber seal that mounts the oil filter housing to the engine. i have seen those leak from time to time. not very common but they do leak. that is right above the tensioner so you might wanna check that out!

as for the noise issue. if it happens when turning...i would guess that is would be lower ball joints and/or sway bar bushings on the front!

Jason

[rman]

i cleaned it off pretty well before i put the dye in..and yes i'm using a uv light, and those awesome yellow stunner shades

there is no evidence of a leak above the tensioner, only below where it mounts and all along the a/c compressor.
It can't be from the r&r because i cleaned up afterward, and it's been a week since then. Plus i used the dye.

I'll have to reinspect today or tomorrow as more oil leaks out.

yeah, and as for the noise...it's more a popping/click noise, i'll put a little grease in the sway bar bushings and see if that does anything (since it's so simple and cheap!)

thanks again for all your help guys

[Nelson Lago]

please help i have that oil leak i think, but cant find it can anyone post a pic please or help me find it

[Espresso]

I know this is a older thread, But since a question was asked i'll post some info......

I had a few leaks like mentioned. The small rectangular tops ONTOP of the cam covers(I even posted in the parts section for part numbers). Also had a leak from the oil filler neck & the oil filter housing base.
For the small caps( I assume they are just for oil vapors, as the tubes just run to the air intake) I just used BLACK RTV. Simple fix but not quick, because the old O-ring gaskets were SEVERELY dry it were stuck & crumbled apart. Once clean I just put on a small bead of RTV & called it a day. Hasnt leaked since(I never had an RTV failure so I do not expect them to leak anytime soon).

For the oil filler neck base. I used Black RTV also. I didnt feel like waiting for months for the part to come from the dealer(BTW this part has no gasket). So I just cleaned it up & put the RTV around the base....no more leaking.

For the oil filter base gasket. I went to the dealer & picked on up. It was like $3. Had to buy a 46mm socket @ $12 to get the bolt that holds the housing off. Pulled up the housing, pulled out teh ROCK HARD gasket, cleaned the groove & installed the new gasket. Took no time, once I got the correct socket.
Here are some pics of what I am refering to.
reference thread for the oil filter housing
http://www.benzworld.org/forums/w202-c-class/1307520-38mm-bolt-oil-filter-housing.html
Oil filler neck. Cannot even see the RTV. Trying to unscrew the ONE phillips that hold the neck on is just about impossible, so IF YOU DO NOT have the parts at hand DO NOT try to take it off.
http://i3.photobucket.com/albums/y92/Black05PT/C280%20sport/Picture246.jpg

http://i3.photobucket.com/albums/y92/Black05PT/C280%20sport/Picture227-1.jpg

http://i3.photobucket.com/albums/y92/Black05PT/C280%20sport/Picture225-1.jpg

[Nelson Lago]

thanks so much but i have another question i also think i have that outher leak the oil pressure port or somthing and thay say its in the left of the engine near the motor mounts what are thay talking about and where is it i might need that too (damm mercedes and their oil leaks its their only down fall)

[Doubleaye]

Hey guys,

I've just done an oil change on a 95 c180 I'm not getting any leaks but the oil light is still on? I've cleaned engine no leaks any chance that my oil pressure is out / leaking? Can any one post pics on where the oil pressure value is?