i have been a mercedes tech ffor many years, but i am having some hard starting and smoking issues issues. i was hoping some suggestions may help guide me.
have replaced:
glow plugs,
injectors
filters
starter
adjusted valves
new battery

You know more than I do but....

compression?

timing?

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

Sounds to me like rings. Using an oil can squirt a pump of 10w40 oil in each glow plug hole and see if it starts faster. It will smoke but the heavier oil will not allow the fuel to slip past the rings.
Are the miles over 250,000?
Is the engine turning over faster than it used too?

My 79 300SD is at this point as well.

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1959 Gravely LI, 1963 Gravely L8, 1973 Gravely C12
1982 380SL
1978 450 SEL 6.9 euro restoration at 63% and climbing
1987 300 D
2005 CDI European Delivery
2006 CDI Handed down to daughter
2007 GL CDI. Wifes

engine granks normal, the engine has under 160k and zero blowby
power is fine, actually runs well. i am thinking it is most probably the injection timing. if it is shut off and started immediately it is ok, if it sets for 1/2 hour it will be difficult to start unless it is glowed first

could the smoking be valve stem seals and guides? have you checked the chain stretch?

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have no worries.....President Obama swears "If you like your gun, you can keep it

i take the zero blow by comment back, it has smoke, but no pressure, is it possible there was something in the oil that prevented this before i changed it? the car runs 100%, i was able to reduce the smoke by adjusting the alda in 1/2 turn. i do notice really no smoke in the day, is it just because of the lights behind me that it is so obvious?

that would be it. diesels naturally smoke. both of mine did the same

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have no worries.....President Obama swears "If you like your gun, you can keep it

Ray, you mention hard starting.

Is it only on cold starts?

On a "warm" restart at 1/2 hour past shutdown, are the symptoms the same as a clod start?

What's the cranking time under each of these conditions?

More data would be helpful.

It's unlikely to be injection timing unless it's wildly off. The engine will start with the IP timing out by 360 degrees with respect to the crankshaft. Will smoke like hell, but, it will start.

it starts fine cold, litle rough then smooths out, the issue is when wasrm, sitting maybe 1/2 hour after shut down, i have had a few diesels in the past and both started easier. unfortunately for me most of my mb experience is with gas models

Problem with the IP rack? Rack damper bolt in too tight?....

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

i was going to check that today. i thought it might be too loose. but i will see what it is set at, i may need to replace it. spring might be too weak?

Bolt may be bottomed out on the rack. If it's too loose, the engine won't have any starting issues.........but may have some extra "shakes". Take a look and see if it's all the way in. If so, back it off one turn and see how it does.

I'm still mulling over other possibilities, but, I don't have any that are not simply WAG's.

On a Ford 6.9 diesel, a bad starter could give you the no start when hot symptom. You might be able to prove or disprove this theory by cooling off a hot starter with a water hose.

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Palangi

2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg



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It does not make a lot of sense but a few examples of other brand diesels (earlier volkswagon non tdi diesel) seem to want a little glow plug time even when warm. Percentage wise it is enough to know it is pretty common. Yet the majority of these exibit fairly good engines. Just something I learnt to live with. I make sure those examples get about 5 seconds of glow prior to energising the starter when warm. Since they start pretty well in the winter I have never suspected compression. Otherwise without that slight glow time they seem to crank hot a long time. Why exactley or where to look is unknown to me on those examples. Cold starts are completely normal. If injection pump timing is late chamber temp might be too low by the time fuel enters is one suspicion on those volkswagons. Since milage was always and currently good as the example I drive now is the same I never really concerned myself with the issue. That does not mean you should not check your primary timing as delayed pump injection is logical with aging.

found problem!!! was the injector nozzles in the rebuilt injectors i installed, i thought i was doing something good. i opened the rebuilt ones, they had french made nozzles, i happened to have a german set of bosch nozzles and installed them in my original set of injectors. all now ok, runs 100% better, starts as a diesel should. returned rebuilt set for credit