oil seperator in rocker cover & oil in blowby - PeachParts Mercedes-Benz Forum

#1 12-20-2003, 07:39 AM

I have an 83 300d non turbo. There is a rocker cover breather that connects the rocker cover directly to the inlet manifold. I'm getting a fair bit of oil laden blowby into the intake manifold. This oil appears as an oil leak down the starter motor side of the engine block and dirty/sooty exhaust on start.

I removed the rocker cover expectign to see some dort of clogged up oil sperator - instead all i find is a metal tube. Am I missing something or is this all that the non turbo engines have? Any suggestions on how to reduce the oil quantity in the blow by before it gets to the inlet manifold.

via a search I see lots of references to blowby oil and air filter housing oil leaks - but these are all for TD engine where, apparently, there is an oil drain from the filter/inlet manifold back to the block. My non turbo has none of this

steve

davidg · #2 12-20-2003, 10:17 AM

What I have found w/ my cars(300D, 240D) is that once oil begins to leak from tubes,gaskets, caps,etc., it continues to leak unless the affected areas are thoroughly cleaned, maybesolvnt first, then w/ hot soapy water. once the leaky joint is clean, the seal in question will work properly again. The oil filler cap and blow-by tube on my 240 (292,000 mi.) were leaking and I removed them and cleaned them as described, and the leaks stopped. hope this works for someone else.

leathermang · #3 12-20-2003, 10:36 AM

On the oil filler cap.. do not turn it upside down when you take it off the valve cover... if you clean it and then always keep it upright you may find it is not leaking.. if you turn it over the oil runs into the top and then runs out when reinstalled...

psfred · #4 12-20-2003, 02:05 PM

Well, blowby indicates engine wear, and other than the oil separator pipe in the valve cover, only the appropriate repair will fix the blowby.

However, a leak down the side of the engine is something else. Blowby goes directly down the intake, you never see it unless something is leaking.

I'd replace the hose (there is a new one, I think, that traps oil better). Make sure the pipe in the valve cover is attached properly, as a leak at the hose connection will allow oil thrown from the cam to get blown out.

A leak down the side of the engine is more likely a leaking intake manifold or valve cover gasket.

If you also have a puff of blue smoke on startup or after extensive idleing, I'd recommend new valve guide seals. Leaking seal allow exhaust to blow up the exhaust valve seal, making an oil aeresol that will carry excessive oil out the blowby hose, and will also overheat the valve cover and cause the gasket to leak.

Peter

samiam4 · #5 12-20-2003, 06:04 PM

I'd drive it on the floor,

Many times short driving and low speed stuff can carbon up the rings and act like a worn motor.

Turbos had an updated breather hose which your car should have if it doesn't.

Michael

redbaronph123 · #6 01-08-2004, 07:45 PM

kinda late for a reply....but i'd like to recycle the thread if i may..

I found out after owning my 79 300TD (non-turbo) more than a year... that i have suddenly gotten some oil in my air filter housing... before it was bone dry every change oil and air filter change.

I just noticed it when i started to have oil puddle on my garage floor. I took out my trouble light as well as my tools and removed my air filter housing and found that there were a lot of oil inside my housing as well as the inlet where the air filter housing connects at. Before i think of piston rings as possible culprit... what other minor stuff can i look at?...

Right now.. i just cleaned my airfilter housing and also the area around it where the oil was dripping or "whatever term to use" around the engine bay. I'll be chacking if the oil comes back within a couple of days city driving.. if it does... i'll probably ask a mechanic to open up my engine to get a closer look...

just a rant: darn it.. seems like my car doesnt want his body restoration done... with this impending engien problem.. i may not have enough money to get my body repaired!.. sheesh...

hehehe.. now that is out... pleasant morning to you all from the Philippines.

Kyle Blackmore · #7 01-08-2004, 07:53 PM

Redbaron , that sounds like a vacuum diaphragm leak. Easy and cheap repair

.Is the oil coming from the hose on the top of the air filter housing?Mine leaked a little bit for a while and then when it finally went there was a liter of oil draining out of the filter housing drain

.

redbaronph123 · #8 01-08-2004, 09:03 PM

thanks for the reply kyle... hmm. didnt think of that (vacuum diaphragm)... come to think of it.. the clear hose that connects on top of my air filter does look very dirty.... i'll have a look at it.. though i do remember changing vacuum diaphragm around july of last year... how did it get busted so fast?... i'll have to check this asap... loss of vacuum is bad... no brake assist, no locks.. and the engine would not die if ever.. ehehheh..

thanks a lot...

Mike.