Hi Guys(and women)need some advice on WHY this happening. A little Vehicle history; bought the car off a guy 5 months ago-it had been sitting in a florida barn for a while...the car starts hard-needs about 15 seconds of cranking-exactly and it fires up and idles pretty smooth.after the purchase,changed the oil,glowplugs, injectors, belts& hoses.Still smoked. Then a local(but not certified MB) mechanic pulled the head and had it shaved and supposedly changed the valve seals--everything back in place--it still smokes-a white/blue smoke. Not much smoke on idle but if you rev the motor a few times it spits out this white/blue smoke. Have 50wt. oil in the crankcase(new) along with a new filter. Had another mechanic(asa cert.) run a compression test--have 315 across all 4 cylinders. I noticed the small primary plastic filter only is only about 1/3 full of diesel at idle and on another MB diesel this was almost full. I disconnected the fuel line completely at both ends--blew it out front to rear and a glob of rust goop came out. I tried to blow the fuel line from rear to front and hardly any air passes through-maybe the reason for the primary(little plastic) filter only 1/3 full of diesel at idle. When I drive the car-in 1&2 gear-it appears starved for fuel--just won't accelerate--could this fuel starvation problem be causing the blue/white smoke?? The hard starting problem-maybe due to the valves out of adjustment?? Could this be a cause of the smoking?? Any advice would be greatly appreciated?? BTW--I pulled the gas tank from the trunk--)it is one of those 37 gal. square tanks that MB sold in that era I am told.)---I cleaned the tank--but did not see a filter-so that wasn't cleaned. This is driving me crazy.!!!!!!!!!!!!!!!!!!!!!!1

To test your fuel delivery, disconnect the fuel line from the tank and run it into a small container of diesel. See how it runs with this direct feed. I think poor fuel delivery could produce hard starting.
The smoke could be a number of things. Oil can enter the combustion chambers via a bad vacuum pump diaphragm on that model I think. It also could be bad or sticking oil control rings. Compression seems acceptable, but you shouldn't have needed to shave the head to get those numbers. I makes me suspect the rings more than I normally would. Poorly adjusted valves can cause hard starting but with those compression numbers, the valves seem to be ok.

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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

You definitely have a fuel line blockage along with clogged filters. Some air in the clear filter is normal, but low power isn't. The tank screen screws into the bottom of the tank, I believe, accessable from below the car. A square 37 gal. tank is likely aftermarket, and may not have a standard screen, instead having a "sock" on the pickup. change both filters with engine hot, fill spin-on with fuel before installing. Prime with the hand pump -- red knob on the lift pump, unscrew and pull/push. New style is a "thumb" pump that is sealed and spring loaded, just push down and release. If there is considerable suction pressure (pump rises slowly or you have to pull it up) you have a line blockage. If you get air moving through the clea filter (as opposed to a bubble sitting there), the suction side hoses between the lift pump and tank are bad and leaking air in. This will DEFINITELY cause hard starts and smoke along with poor performance, and is the cheapest fix....

You are also at the low limit for compression -- likely have worn piston rings and cylinder walls -- did your mechanic check them when the head was off? Should still have honing marks. If they are gone and the walls are nice and shiny, they are worn out.

Valve adjustment will help here.

I would also check the chain stretch -- likey it's badly worn, so both valve and injection timing are late.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Kerry/Edwards--Thanks-I will check out some of your suggestions. Miki

Peter-Thanks for your time & advice--I'll check your ideas! Mike

If I am right, you have a cigar hose on that car too, it is an odd shaped fuel line between the metal lines coming from the tank, and the filter. Often that line gets rotten with age. When it does sometimes it leaks fuel, other times it sucks air into the line. Car won't have any power if it does that.
Pull it off and plug the end, blow into it. It air comes out the sides, replace it also.

Old Deis-Thanks for the info-I will look at it--Mike

Which type of primer pump do you have? If it is the old style with the red knob, they are prone to leakage. If it leaks fuel out, then it leaks air in. That would also contribute to the hard starts.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

Put a new one in-believe its got a white or creme colored knob.