Well it was a nice day so my dad suggested we tinker with the Merc a little. Since I have not gotten the manuals yet and have no parts we couldn't do the glow plugs. But we Gunked the engine and cleaned it real well and traced some leaks. The 2nd injector back is leaking real bad from that braided hose on top. You guys were right, boy can those suckers leak! I also found out my transmission lines are leaking, and theres a colent leak comeing from somewhere but thats not important now. What else I found is a little bigger problem. As some of you guys know my car is a little harder to start and skips more than it should, well I think I've found out why. When I was listening to the engine I heard a different "clatter" not the normal kind but a distinct sound that didn't sound right. I guess you would call it "nailing." So useing a piece of wood we traced to back to the 4th and 6th injectors. You could feel it in the fuel lines if that makes sense. When the fuel lines were cracked on the 4th the sound went away and it improved when no. 6 was cracked. So now I guess I need a set of injectors, my queston is can I just buy 6 off FastLane and put them in, or do they have to be set? I talked to a very good diesel mechanic and he said on some of the larger diesels one injecter might be used on a few engines and then they would have to be set. He said these should be fine and to just screw them in. What say you?
BTW he also said the proper term for them is nozzels not injectors. This engine doesn't have injectors.
Sorry for the long post.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It's perfectly fine to install them straight from the box. It could not hurt anything to have them pop tested to be sure they are to spec.

May I remind you that this is a 300SDL

Before spending upward of $300 on injectors, try a bottle or two of Lubromoly Diesel Purge at full potency into the IP.

You might also read up on delivery valve seals since you'll have the intake manifold off to do the glow plugs. From what I've read in MB Diesel forums, new properly installed delivery valve seals take care of nailing more times than new injectors.

Sixto
95 S420
87 300SDL

Sixto the coolent leak is from the bottem of the radiator or the lower hose. Somewhere in that area, since I'm not driveing it and plan on doing a major cooling system service before I do it is low on my to do list. First I need to get it running right. However what are those delivery valve seals? Where are they, this is the first time I have heard of them.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Right where each fuel line to the cylinders meets the IP, there's a splined nut held by a crowfoot retainer (maybe there's a better name for this). Insde the splined nut you'll find a needle, a spring, a metal washer and an o-ring. No idea what delivery valves do but replacing worn o-rings does a world of good. Replace the metal washers as well since they're cheap.

There's disagreement between the shop manual and maintenance manual so read the archives for advice. The shop manual says to torque the splined nuts to 25-Nm or some such number. The maintenance manual which is not part of the W126 CD set for some reason says to torque to the same value but adds to do it two or three times giving it a rest between steps. I think it's to seat the o-ring properly.

Have you priced a lower radiator hose?

Sixto
95 S420
87 300SDL

Yes, it's $87 give or take. Why so expensive? Thanks Sixto might as well as do those while I'm in there.
I am alittle parinoid about the 603, and since the cooling system seems to be original, I will replace the following:

All cooling, and heater hoses
Thermostat
Water pump
Radiator
Expansion tank, line and cap
Fill with MB coolent (thats what seems to be in there now)
I'll do the belt to.

The radiator is expensive so I might wait on that a little.
Anything I missed? The fans seem to be in good working order.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Re: Delivery valve seals.

Do you also have rough running that smoothes out as the turbo comes up, but no smoke at all? If so, I'd suspect the delivery valve seals

Proper installation of the copper seal is the problem -- the rubber o-ring seals the low pressure supply side of the pump, and they get old and leak. New 0-rings get put on, and the old seals are re-used, or new seals are installed and not torqued properly, and the delivery valve leaks. It's there to hold the pressure in the injector and line so that when the plunger pushes up in the sleeve inside the pump to deliver fuel to the combustion chamber, the nozzle pintle lifts immediately. If not, injection will be very late and the cylinder will knock badly at idle from delayed burn. Less than normal fuel is injected as well, so you have rough running from a "dead" cylinder.

The cure is to locate the special splined socked, remove the injector lines and lock rings, and re-torque the pressure valve holders -- pull 25 nM twice, then 30 nM WITHOUT loosening the holder between. I would guess the seal extrudes badly, and if not re-torqued twice, leaks. I got my 300D pretty cheap because three of them were leaking and the mechanic was afraid the head was gone. One pressure valve holder was only finger tight! New seals fixed it.

If re-torqueing doesn't work, put new seals in ($8.36 for seals and o-rings, part numbers have been listed in the past).

If you still have knock problems, pull the offending injectors and have them tested -- they usually don't go bad unless you run a large amount of dirty fuel through them. The ones on the Volvo are fine, at 220,000 miles.

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!

Forgot to mention - take a good look at the belt tensioner pulley (the small one with no grooves) from directly above. If the pulley is the slightest bit misaligned (rotation axis pointing to the driver seat rather than straight fore and aft), it's likely time for a new tensioner or a new pulley. A more accurate test is to check the motion of the tensioner with the spring and shock released. It should move smoothly with no rough spots or 'clicks.' The pulley should spin smoothly with no whirring or wobble.

Sixto
95 S420
87 300SDL