I replaced the head gasket because of a thick white smoke. I changed the timing to 20 deg BTDC. I cant get to 24 deg, the chain is stalling when I crank it. So I decide to stay at 20 deg. I adjusted the valve .1 in .3 exhaust. The problem is that I can hear a knock sound. When I checked the piston it seems ok. It is tight and no scratches in the sleeve.

It is easy to start. It doesnt heat past 80 deg after 10 min idling. There is a bluish blackish smoke that is lesser before I changed the HEAD gasket. When I checked the vacuum pump, there is no pressure so I removed it and discovered that the hex srew holding the diaphragm is disengaged. Lucky that it can be repaired. I am hesitant and think if there are other things wrong with the engine. So i need your help on what else to check before assembling the engine. It is very tiring to assemble and dissasemble.

I removed the oil pan to check on the oil pump. I need to know what to check on the pump or how to check if anything is broken. I don't have a manual for the oil pump and even the vacuum pump. I have tyo be sure about the proper angle to screw in the vacuum pump.

I doubt I can help you as I am a neophyte here, but it might help if we knew what kind of car your were working on.

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86 300 SDL - Vesuvius

96 SL 500

Assumption is the mother of all screw ups.

Do not go gentle into that good night. Rage, rage against the dying of the light. - Dylan Thomas

All that is necessary for the triumph of evil is that good men do nothing - Edmund Burke

I am working on a 79 300D manual. I have a 79 300D matic. The manual is just newly acquired. I am hoping to rebuild it and use WVO for fuel.

Hmm..everybody seems busy...

If you are asking how to check blowby, most people warm up the engine then remove the oil fill cap at let it rest in place. The less it dances, the better. If it flies off, you've got a lot of blowby.

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

THanks a lot!! I'll try to check that tom!!

The problem you are trying to resolve is not clear to me. The thread title asks about blowby but the content seems to relate to a smoking engine. Are you trying to get rid of smoke or are you trying to figure out how much blowby your engine has?
One item to consider on smoke, is that the 79 will suck oil thru the vacuum diaphragm into the intake if there is a hole in the diaphragm, causing smoke. to determine if it is sucking oil, look inside the hose that goes from the vacuum pump over to the air filter.
Can you clarify what your problem is and what steps you have taken to resolve it?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Could be injector knock. Try cracking lines at injectors to see if noise goes away. If it does, switch that injector with another hole and see if noise follows it. I've had knocks and smoke because of fuel leaks at the return lines and also faulty or crushed heat shields. And I also have a bit of blowby--doesn't blow the cap off completely, but dances a little. Do a search on blowby and you'll find that it's really not a big deal on the whole. If you have it, really the only way to fully remedy it is to tear down the entire engine and rebuild. And like you've said, it's a hassle to disassemble and reassemble. Good luck!

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1998 E300D, 287k, barely broken in.

KERRY was right about the vacuum pump. It may send some oil to the intake manifold. The reason I am asking about the Blow By is because of the knock that I heard after I ran the engine. My first problem is the thick white smoke coming out of the exhaust. I removed the HEAD and replaced it with a new head gasket. I readjusted the valves and re align to 20 deg BTDC. Why 20 cause when I go 24 deg, the chains stalls when I am manually cranking so I settled for a 20 deg.

After running the engine, the thick white smoke is gone. bluish blackish smoke replaced the thick whitish smoke. It was not that thick so I also tried adjusting the IP. I got a lesser smoke but there was an intermittent knock that I can hear coming from the bottom part of the engine. I first suspected the oil pump. After removing the vacuum pump and finding that there is a loose hex bolt, I still am thinking of other things that may give off that sound. So I removed the oil pan to expose the oil pump. I was surprised that I cannot check all the connecting rod bolts. I was also thinking that it may be loose.

THat is why I am asking you guys if there are other things that I have to check. GRIESL was mentioning the IP. That I also have to check but the question is if I have to put all back and run the engine or pull the engine out to check on the crankshaft and the conrod bolts? It is really very tiring to assemble and disassemble. THanks to you guys, I seem to be enlightened by the facts and will have to check tom. It is raining here to day so I cant assemble the engine and run it. I am also trying to figure out the valves on the vacuum pump in what direction the coin size valves will be facing.

Thanks again for the guidance guys!!

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79 300D automatic 190k
79 300D manual under repair

Search on vacuum pump rebuild. There was a recent post with pictures of which way the check valves go.
You can figure it out by sucking and blowing on them. The pump has to blow over to the intake and suck on a vacuum line. So the valves must allow it to do this on the respective lines.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Thanks KERRY!!! MAybe I can work on that even if it is raining. I saw a thread but it seems a different model of vac pump.


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79 300D automatic 190k
79 300D manual under repair

Just saw the pics of vaccum pump repair. Thanks!