I was trying to do a tea-pot test by removing the oil filling cap. I loosen the cap and I did not find any pressure or vapor coming out. Instead I felt the cap was being sucked slightly into the opening. It did not dance around or move. Engine has 250K miles.

Good, bad or indifference?

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Good, sounds like you have minimal blow-by. When you change your air filter every 30K miles there should be absolutely minimal amounts of oil on it.

Dkr.

Is your air filter plugged up?

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Which engine (in your extensive list)?

(Disconnect and plug all by-pass crankcase gubbins and try again!)

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

It is a 87 300D OM603. Car runs fine. I have not taken it to the open road yet as it is registered as no-op. What can cause negative pressure inside the valve cover?

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Turbo?

Yes.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Indeed - alternatively perhaps air being drawn from the crankcase into the intake as some form of emissions control (gone wrong / malfunctioning)

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

What route would be taken for crankcase air be directed to intake in a turbo engine? Except a completely clogged air filter drawing air in through the breather tube.

Did I specify it is an OM603 turbo in #5?

MxFrank - I misinterpreted your post 'Turbo?' as Turbo engine? and not it could be caused by the Turbo.

None of the other turbo OM603 give this strange behavior hence I asked the question. May be the 87 300D has the best engine of all. It is probably true as it has more power than the rest. Thank you all for the answers. I am happy now.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Glad you figured it out!

"What we have hear, is FAILURE to communicate!"

Almost every single organizational failure is either caused by or contributed to by a break down in communications; this forum is no exception.

Writing well, so that what you mean to say is understood correctly by the other party, is not easy, and this thread is a great example of that. I understood what MxFrank was saying, and agree with him, but now I see that your understanding of his post and my reply did communicate what we intended.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

In general, some diesel engines have a check valve that allows air to exit the crankcase but not reenter. I don't know if you engine has that or not.

Re-read post #3 & 4. The PCV sucks on the crankcase. Gas engines suck pretty hard (via intake manifold vacuum). In your diesel, the only vacuum is from the pressure drop across the air filter + ducting. I first disconnect the PCV and leave the larger oil fill cap on. If I see minimal puffing from the little PCV port, that suggests the piston rings are excellent.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Removed the air filter completely. Still negative crank case pressure, it is sucking the oil filler cap down. I think the engine is sound and runs well. Just wondering what can cause negative blow-by. Anything I can check or just be happy?

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

You don't seem to be reading the replies

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!