Two oil leaks OM606 - PeachParts Mercedes-Benz Forum

jake12tech · #1 03-25-2018, 06:31 PM

My 99 E300 has oil at the intercooler hose right next to the radiator on the driver side. It also has an annoying leak at the intercooler pipe where I guess what is a some kind of sensor to measure the fresh air going into the intake. When I bought it, that intercooler pipe was COVERED in oil. Caked. I've cleaned it but every week I have to spray it off as it has oil.

The turbo is a replacement 80,000 miles ago so all I can think is that it's crankcase pressure at 541k. Anyway to stop the Oil? if I don't clean it, I'll notice a penny sized drop in the driveway and a dirty engine.

jay_bob · #2 03-25-2018, 06:53 PM

Crankcase breather puck has a blown diaphragm. It is located under the decorative cover.

torsionbar · #3 03-25-2018, 08:55 PM

Hard to picture based on the description, but there is a large rubber O-ring that goes between the EGR valve and the metal piping from the intercooler. This o-ring fails after a while and leaves an oil mess all down the intercooler piping.

jake12tech · #4 03-26-2018, 01:48 PM

Thanks guys. that o ring was replaced less than two weeks ago, I know what you're talking about.

Jay Bob, best bet is to buy the CCB Puck? That'll stop the Oil leaks at the intercooler hkse?

jay_bob · #5 03-26-2018, 06:54 PM

Yep. Take off the 8 hex head screws and lift off the plastic cover to access the puck.

If the diaphragm is blown it will push oil down the breather hose exiting at the front right corner, into the big black air hose coming off the air box into the turbo inlet.

The oil goes through the turbo and intercooler and it comes out the far side. It deposits on the inside of the turbo and has caused many to think their turbo is failing.

Same situation that happens on the OM642s where oil leaks out at the breather connection to the turbo. In this case instead of soiling your driveway it drips onto the swirl flap motor and kills it. Then you get to take the whole thing apart...