This might not have to do with the smoke, but I had a 602 turbo in a 190D and when I replaced the hydralic motor mounts, the idle roughness and valve noise went away. Does the 124 have the same type of mounts. Might not help with the smoking/non shut off, but I thought I'd throw in my two cents.

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87 190 2.5 TURBO! 321,000 needs help
85 300 123 waiting for the day-----
79 300 123 this side of junk

The shut-off actuator has an o-ring that's easily replaced (well, as easy as removing the shut-off actuator), the control rod sensor connector inboard of the shut-off actuator has an o-ring that requires the IP to come apart to replace, and the ALDA is known to leak oil from where it attaches to the IP. No seal between the ALDA and IP.

Could also be oil leaking from the junction between the crossover pipe and intake manifold. Easy to replace the gasket.

Sixto
93 300SD 3.0

it looks as though it is the o-ring on the shut-off actuator. it clearly comes out right there. I don't think it's the ALDA or the crossover pipe, which also recently got its gasket replaced and got all cleaned out professionally, as well as the intake manifold...
when you say the shut-off actuator, you mean the lever that you press to manually shut off the engine ( that whole assembly that attaches to the IP there on the side), right?

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

I don't think mine has hydraulic motor mounts. Are you sure you mean the mounts? Or the engine shocks? But I've never heard of them being hydraulic (which doesn't mean anything, this car is new to me.... but there should be a hydraulic pump and reservoir somewhere if that were the case, right?) Well, but in your car, surely there were other symptoms than just valve noise and idle roughness?

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

Actually, no. I meant the vacuum shut-off actuator. There's an o-ring on the shut-off lever shaft but I can't find a part number for it and it's not available separately from MB. I heard an o-ring from the oil filter center shaft will work but I found one that worked in an o-ring variety pack from Autozone or Kragen.

Sixto
93 300SD 3.0

good to know (about the Autozone pack).
so the vacuum actuator...where is that? on top of the IP, the little bell shaped thing where the brown vacuum line goes in?

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

Yes.

Sixto
93 300SD 3.0

so...
- shut off is solved. it was the vacuum switch on the ignition switch itself (damn that panel under the steering wheel doesn't come off as easily as I am used to in my 123's)
- oil leak on the IP was the o-ring on the shut-off actuator...unrelated.
also: turns out that it had been overfilled with engine oil. it was slightly over the max on the dip, and I had to take out over a quart to get slightly under max. People are telling me that these cars should never be filled more than half way up the dipstick or else the oil froths up in the crank shaft and the valves fill with air and don't function properly...
BUT... the bigger issue is not resolved: it's still doing its weird tripping and smoking and valve clatter. First starts up smooth as silk (even at 5 degrees out, and one GP cycle), after 2 minutes of idle, it starts tripping, like one cylinder isn't really firing, smoke, valve clatter...until it's fully warm. But the first two minutes it runs super smooth. So indeed no glow-plug issues, I think. I came across an error/repair report from MB that describes exactly those symptoms, and it says that there is some problem in the head gasket by cyl.1 which doesn't, at certain temps, not at cold, and not at fully warm, but inbetween, let enough oil flow by to the valves and causes these symptoms....I'm having a local MB mechanic look into this further, but it looks like it might be a shot head gasket, even though there are no other symptoms. no oil in water etc. It sucks!

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

Remember that the 602 has "afterglow", where the glow-plugs stay on after starting. You might be idling well until the glow-plugs time out.

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Gone to the dark side

- Jeff

do you know how long the afterglow last, in the case of a 602 engine
and wouldn't a glowplug have problems preglowing as well if it ended afterglowing sooner than the others?
or do you mean to say something much more nasty, i.e. that everything is fine as long as there is glow, but that the engine itself may be pretty fried, and as soon as the afterglow is over, it shows its real ugly face..... sorry, i just had a few glasses of wine....

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1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

would the afterglow be as long as 2 minutes?

__________________
1974 240D, 125K mi, B100 now, SOLD
1980 300TD, 115K mi, 4-speed stick, roll-up windows, greasecar with two tank conversion (daily driver)
1985 300D, 220K miles, greasecar with two tank conversion, SOLD
1993 300D 2.5turbo, 158K miles, green/tan, B20-B50

You simply measure for applied voltage to determine your afterglow but two minutes sounds reasonable. Allow that I am not familiar with this engine type at all. Sorry about the curve thrown about the possibility of the head gasket. This sounds like the kind of issue that should be done by callback if true. Mercedes may be getting away with a lot more than it should.

If you have valve tappet noise rather than injector knock (valve noise doesn't go away with speed increase, injector knock usually does), change the two o-rings on the center "bolt" on the oil filter cover. They are very likely rock hard and leaking, and this allows the head oil gallery to drain down at night. It takes quite a while for those tappets to refill, so if you are draining them every time the car is off, well, they clatter. They may be toast, too, easy enough to check next time you have the valve cover off. If you can push them down with a screwdriver, they are bad (or full of air....).

Definitely check the timing, and also run a bottle of RedLine or Diesel Purge through in a tank of fuel, this will clean up dirty injectors so long as they aren't damaged or stuck with anything but carbon. You have burn problems at idle, but the can be a number of things. Most likely it needs a "drive it like you stole it" highway trip to clean it out. Does wonders for diesels, driving them around town like a little old lady gunks them up terribly.

You need to check the vac source and operation of the shutoff valve servo -- the supply line is way over on the fender side, and by now is quite brittle, and is likely cracked. It connects to the power brake booster line. I would als suggest a MitiVac hand pump.

If the servo is bad, there will be oil in the lines, and you will need to flush it out or it ruins the keyswitch, and that's a pain to replace.

I have a worse problem -- the seal on the shutoff lever is bad and the lever binds down and I have to pull it up with the key on to start. Anybody know the part number for that seal?

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!

the after glow is about 3 minutes IIRC.
I hate to say it, but a compression test may be in order for you. and just cause the injectors were tested recently it doesn't mean they are not bad.
I would start the car, let it idle and verify with a VOM that the GP's are getting power while it idles smooth, and the power is dropping out just as the rough running starts, then I would loosen each injector to see if it's one particular cylinder causing the ruckus, then I would pull that injector and swap it for one of the others that is running fine to see if the problem follows the injector. then if not check compression on that cylinder.
John

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

My guess is u have to replace ur timing chain, cam sprocket and chain tensioner to solve this problem.

I had similar problems and did the above.

There is a FSM out for this model relating to ur problem..