Allright finally had time to get into valve stem replacement.

First question: There is bent wire around each set of arms that I am guessing serve as retaining clips of sorts. Anyway if you look in the attached photo you can see that the "clip" for the arms on pot #1 is not in the grove on the arm assembly like the other 3 are. I am assuming it somehow slipped out of position, fair assumption? Any worries here? I just plan to move it back into position.

Second question: The FSM says to "mark the rocker arm assemblies to show how they fit on camshaft" How they fit seems pretty self evident to me, am I missing something here? I wouldn't know what to mark.

Attached Thumbnails

 

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1972 280SE 4.5

The clip prevents the rockers from moving sideways along the shaft. You mark the rockers with typex or similar so the arms go back on the cam lobe where they started. Mix them up and you run the risk of mismatched surfaces grinding themselves apart.

By this you mean I need to be certain the rocker arms from cylinder number one go back onto cylinder number one not cylinder number three?

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1972 280SE 4.5

yes you want the rockers to go back in the exact same spot. If you leave the clips on you wont have a problem at all.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Well I replaced the valve seals, but I have to say the old one's didn't look to be in that bad of shape. Only one or two looked even slightly misshaped. I was worried this might not have been the problem, and after todays drive I can say if anything more black smoke. I guess I will recheck the valve adjustment since I was a little tired of bending over the fender at that point. It will take some time driving to see is oil consumption has changed.

This makes me wonder about mercmad6.3's comments about valve guides.

I did take a look at the FSM and unless I am missing something it doesn't seem "dead easy" to me. For one thing the head is all the way off.

I guess I will look like the guy in BMW's new diesel commercial for a while.

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1972 280SE 4.5

It's not hard to remove the head but black smoke in a diesel is caused by Too much fuel and too little air.

So with this in mind go back to the beginning and check that the throttle links are not worn ,allowing the injection pump to open more than the throttle plate ( too much fuel,not enough air) .
If that is OK, check the oil level in the rear of the pump. The governor is affected by too much oil which causes the pump to over fuel ( too much fuel etc ) .
If the pump is in good condition, try the engine without the air cleaner .
Again a situation where too little air causes smoke.

Then there are worn injectors, if the nozzles are worn, the spray pattern is affected and there are dribbles formed. This prevents the fuel from igniting and it in urn produces lots of smoke .
Pull your injectors and get the local diesel place to test them for you.
It can be expensive to sort out but you wil only need to do it once and chances are you will get decades of use out of them.

Bad injectors often have a side symptom: loud nailing. Just another piece of the puzzle.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Thank you, that idea solved my overly rich mixture, the black smoke has cleared!

Bad news is puffs of white smoke after waiting for a light tells me I am still burning oil. I guess I will read more about the valve guide replacement.

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1972 280SE 4.5

great,a bit more tuning and you will have a great running car. A good alternative would be to track down a cylinder head and over haul it at your leisure . Then you can still enjoy rattling around n your car without taking it off the road for a long period.

.....do you mean that you see a momentary puff of smoke upon acceleration from a dead stop and that is it?

If that is the case and the smoke only lasts about 10 seconds, then its about normal. It might just be normal. If it just keeps smoking, not really a puff, then you are correct to keep seeking a solution.

Check your fuel filters?

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

When I pull away from a stop I can see white / grey smoke hitting the front grill of the car behind me. Whether or not the smoke output then decreases is hard to say, as the slip stream may simply be dispersing it to a point I can't see from the rear view. I will try getting someone to drive the car while I follow to get a better idea.

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1972 280SE 4.5

I asked because my car had that problem. But I could tell from the rearview mirror especially at night with headlights behind me as the trailing car gagged.

Put trans fluid in the tank and an italian tune up and it cleared up.
Also changed the oil and oil filter.
Later had to replace both fuel filters and also added 7cc of biocide.
No smoke at all now.

anyway, 9-10 seconds of smoke is about normal but not extended smoke screens !

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

I was reading through this again, do you literally feel a "pop" when the seal is sits in place? I did not but pressed them down hard pretty hard with my fingers.

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1972 280SE 4.5

you wont feel a pop, but you can deff feel in your fingers when the seal seats into the groove on the valve guide.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

The vacuum for the governor of the pump is not created by a vacuum behind the butterfly valve, but by a venturi under the butterfly valve. The valve controls the amount of air flowing through the venturi. Also an increase in the speed of the engine will increase the air flow through the venturi.

The vacuum works upon the membrane. The membrane connects to the rack, so more vacuum and the rack moves towards the stop position. There is also a spring inside the governor that pushes on the membrane and so, if there is no vacuum, the membrane moves the rack to the full load position.

The rod to the IP controls the auxiliary mechanical governor, i.e. the poppet cam. That steadies the rpm at idle and at low speeds, otherwise the engine would be "sawing".

In the picture below you can see it. Nr. 8 is the rack, nr. 10 the membrane, nr. 13 is the spring, nr. 15 is the poppet cam.



If the governor housing is not air tight, more vacuum is needed for a certain engine speed. More vacuum is created by keeping the butterfly valve more closed and that will cause a rich mixture and smoke.

You did replace the membrane, but did you check whether the governor housing is air tight? It can also leak from the axle of the poppet cam (and it frequently does).