seems to be an Om642 oil cooler leak, but ??? - PeachParts Mercedes-Benz Forum

ariquelme · #1 06-19-2016, 08:07 AM

Hi all. I'm new here and I am impressed about the forum contents. Looks to be the right place!!

The car is an ML 280CDI, year 2006, but searching for the VIN information at (17vin.com), seems to be manufactured on Dec/2005.

Now the problem... All symptoms looks like the oil cooler seal is failing. After a ride when parking the car there are 2 oil leaks, about 7 to 10 drops comming down from the front left and rear side of the engine.

An why did I add the "BUT ???" in the post title?, Well I have rise the car, then start the engine, let it take the normal tempeature while I got under the car to see how the leaks are going on.

Ummmm, NO leaks, so back into the car, and this time rise r.p.m. (while in parking position) to 2000 r.p.m. for a couple of minutes. Again under the car to see the leaks. Still no leaks, so back to driver's seat and this time started to accelerate and decelerate the car from idle to 3000 rmp for several minutes. No drops at all. Taking a more in deep look all around while the engine keeps running, confirm there are no leaks.

Now I decide to do a short drive (about a 1 to 2 Kms - 1 mile), and shortly after turning off the car engine, I saw a trickle of oil coming down from the upper left/front side of the engine (can't see the origin as there is too much stuff around with no space to see) but I'm sure is the front famous drain hole in the V. Same with the rear coming from the upper part of the engine/transmission box area.

I have to check this again, but it seems the leak starts just when engine is turned off after a ride, but not while the ride.

So... is the cooler leak suppose to behave that way ? Only after making a ride, but no while car is stopped, even if the engine is running ?.

If not, what other else could be ?. I have already checked the other typical oil problems at the turbo intake, and there is no oil comming from there.

Many, many thanks for any help

Antonio

GregMN · #2 06-19-2016, 10:44 AM

It sounds like the oil is pooling somewhere and the act of accelerating and stopping is sloshing the oil out of the pool and down the engine block.

2008 ML320 CDI - Oil Cooler Seals Replacement - MBWorld.org Forums

ariquelme · #3 06-19-2016, 01:02 PM

No, maybe I explained wrong. When I lift the car with the jack and I accelerate and keep it at idle rpm to simulate a normal ride, no matter what I do: There are no leaks.

Also if I make a real ride, there are no leaks until I turn off the engine, and only this way the leaks start. I mean... After a ride and before turning the engine off, I took a look at the under side of the engine, and there were no leaks untill I turned off the engine. Moment in which oil leaks start.

I don't know if there is any valve in the oil circuit that when the engine turns off, it gets closed and the oil circuit remains under pressure and starts leaking oil while the pressure is released. The point is that the oil is accumulated in the V pool, as the leaks are coming from the front/left and rear side of the engine, where the drain holes of the V pool are located.

What I would like to know, is if the typical oil cooler leaks start only after the engine is turned off, or they remain leaking while the engine keeps running. And in case that the leaks remain always while the engine is running, then what is going on with my car ? I am getting crazy to understand this.

Antonio

GregMN · #4 06-19-2016, 02:17 PM

Ok, I think I understand. But just to test my theory, after a test drive, park, but don't turn it off and see if the leaks appear the same as if you parked and turned it off.

Otherwise, I do not know of anything in the lubrication system that would do what you describe only after the engine is shut down.

ariquelme · #5 06-19-2016, 03:59 PM

Ok. Right now is lifted with the jack, but tomorrow I'll make a drive test and let you know the results.

ariquelme · #6 06-21-2016, 04:34 AM

Quote:

Originally Posted by GregMN

Ok, I think I understand. But just to test my theory, after a test drive, park, but don't turn it off and see if the leaks appear the same as if you parked and turned it off.

Otherwise, I do not know of anything in the lubrication system that would do what you describe only after the engine is shut down.

Tested! After a test drive and parked while engine is running there are no leaks. After engine is shut down, the leaks appear. It also sounds a very tiny noise like bubles, difficult to check what part of the engine is coming from

Antonio