i have been trying to solve some smoking issue. i get puffs of white/gray smoke at start up, and always under heavy acceleration. it disappears at idle once the car is warmed up. also, the smoke is primarily visible at night, not very noticeable in the daytime (except by smell). the car runs very well, and gas mileage is good (around 22-24 mpg).
so first question, is this just normal and am i being obsessive about the smoke?

second question, still obsessing, how can i solve the issue?

the solutions that seem reasonable would be -
new valve seals - smoke kind of stinks like diesel or oil - i can't tell which - but i run B100, and even ran out of fuel the other day so am certain there is only B100 in there, and no i didnt run out of fuel on purpose. would b100 smell like diesel? that makes me suspect oil, so maybe valve seals to fault.

new injector nozzles - i have the old receipts for maintanece and have "R&R prechambers and injectors" at 203K, am at 259K now.

any thoughts on that?

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1979 300TD wagon (non-turbo)
266,000+

Do you know your rate of base oil consumption? You cannot have smoke and not be burning base oil over time. Unless your seeing fuel smoke instead that is.
Make sure your injection pump timing is on and not retarded. Compare your car with one considered normal.

These heads can develop a loose valve guide sometimes as well. A new set of valve rubbers might help a little if it turns out you are burning more than say one quart every 1000 miles of base oil. At least the valve rubbers are pretty cheap and not difficult to do. Even if they make no difference afterwards.
Have a look at your smoke. is it noticably black or tends towards blue. You have checked the condition of your air filter? If in a gross condition it will strangle the engine for air and make for poor smokey combustion. On the otherhand for an older engine it might be just in the normal range of emmisions. I still think the rate of base oil burning is a good indicator of whats going on if anything. If you basically have no oil leaks to invalidate the rate.

don't think you'll ever get rid of the smoke under heavy acceleration unless it's a modern (e.g a CDI or something) diesel. smoke is caused by being outside of the diesel combustion map and fuel is exceeding the rate that air can be fed in. There's no way to fix this unless you have a computer to keep the two elements in sync with each other.

__________________
1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

Thought I would revive this thread with some progress. Really not much progress, just giving myself time to watch oil consumption and gas mileage. After 2500 mile since last oil change, still have not needed to add any oil (or coolant for that matter), which leads to my original prognosis that the smoke is fuel related. The smoke is white/gray visible at acceleration from a stop, day and night. It's not enough for someone to flip me the bird, or cover their car, but enough to be visible when I look for it. Should note MPG ranges 22-27, which seems good to me.

So next steps-

Diesel Purge (can't hurt)
Check IP timing / Cam timing
New Injector nozzles (still original after 260000 miles!)

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1979 300TD wagon (non-turbo)
266,000+

To add to the list....
1)Valve adjustment
2)Water/methanol injection system.

Yes, even B20 will decrease the strong diesel smoke smell, B100 will eliminate it. It will also cut down PM's (particulate matter, smoke)

__________________
1999 E300DT (131,800) 154,000 Black on Black SOLD

2006 CLK 500 coupe Capri Blue on Grey (zoom,zoom)
47,000mi

04 VW TDI Passat 80,000mi
(Techno)

How to eliminate oil dependency through market-driven approaches.
“We could cut oil use in half by 2025, and by 2040, oil use could be zero,”
The Sound of Diesel Speed
Ode to MB

valve adjustment was done at last oil change (2500 miles ago).
what is the #2? water/methanol?

i have been running B100, and the engine runs considerably better than on D2, or even B20. there is still a slight smell, but definitely not like straight diesel, and there is still smoke - it seems to be more white with b100, more gray with D2. i suppose with B100 the particulate matter is non-toxic.

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1979 300TD wagon (non-turbo)
266,000+

My smoke seems to be fuel, I can smell it. When I burn bio it almost seems like there is more smoke. It just smells better.

I did the valve adjustment and that seems to have helped a little. But that helped the performance very noticably. My next step is cam timing and valve seals. I did a purge but it did not seem to do much overall, but the cloud that it produced was amazing! I had an eight foot tall "rooster tail" as I drove around the block.

It will probably be a couple months before I can address this issue again. If you find a magic bullet, please post!

__________________
Sonny


86 190D N/A 2.5L Auto 265k "Ruby" -Sold-
79 300D 242k "Condi" my first -sold- RIP
2013 chevy sonic hatchback - had to for work

http://www.usdieselparts.com/pages.cfm?ID=157

__________________
1999 E300DT (131,800) 154,000 Black on Black SOLD

2006 CLK 500 coupe Capri Blue on Grey (zoom,zoom)
47,000mi

04 VW TDI Passat 80,000mi
(Techno)

How to eliminate oil dependency through market-driven approaches.
“We could cut oil use in half by 2025, and by 2040, oil use could be zero,”
The Sound of Diesel Speed
Ode to MB