Yes, the salt shaker can glow and glow plugs not glow. The power goes through the salt shaker first. If there's a short downstream of the salt shaker then the power goes through the salt shaker to ground at the short. Shorts are usually due to carbon from lugging the engine. Those ceramic discs will crack and short out if you tighten them down too hard. Quick and dirty check is to feel the wavy hangers. They get hot. Another tip: if a short occurs then at least one upstream glow plug will usually blow out from the high voltage. Then you have a short AND an open to fix. But the best way to troubleshoot is to use a voltmeter, starting at the glow system ground strap and working your way upstream.

I'd do a leakdown check, even on a cold engine. It's possible the head gasket went far enough to not allow a start, but I'd pull or push start it before opening up the engine.

Just re-read MattDave and saw the fatal clue: wet injector. May be blown injector tip, may be head gasket. Get that injector tested for crack and spray before opening the engine. At this point you might as well test all four. Remember to install with new seals and make sure that the old seals are out.

I've never understood this "hydrolock" thing. If you're going to squirt oil into the cylinder then you're going to spin the crank before you button it back up. The closest thing I've seen to "hydrolock" is a gas engine with a gravity fed downdraft carburator (riding lawnmower). The float failed and the engine flooded with gas.

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daBenz - 1970 220D

fshacker and dabenz,

If you have a short to ground, the resistance wire in the "saltshaker" will glow but much quicker and brighter than normal. It will actually burnout if left on too long with a bad short in a GP.

A voltmeter test at each GP should tell you if any GP is shorted. The voltages should be different at each GP. If any GP read 0 volts or very close to it, one of the GP is shorted.

I think your problem is low compression. Bad fuel, I have never seen any that would would cause an engine in good condition not to start and I have used fuel more than 10 years old.

P E H

I agree... the salt shaker light hasn't changed since I bought it when it started fine. It takes about 15-20secs to reach full brightness. We also measured the voltage across the glos and they check fine. The glos are beyond suspicion now. They look so identical to a new set that I bought as a spare, you could tell both sets have left the assembly line same day in India. The internal resistance is identical between the old and new ones. The only change I found is the open resistance between the poles and the outer body. The new ones reach 22M Ohms, while the old ones will be in 500K Ohm range. I suppose it is still high enough to be open circuit at DC level. Perhaps the old ones' outer insulation will change resistance overtime due to heating and cooling.

It is I guess down to compression, but we are not sure if it is rings or valves or head gasket, or a combination of these. I guess the leakdown test is hopefully the final way to tell.

Does anyone know if removing the head would require discharging the AC? I'm told the AC on this car is an afterthought and its bracket is in the way of getting the head out. Too bad if it does and we have to get the head out... the AC is very cold.

Thanks!

fshaker,

Its been so long ago that I worked on my 220D. I do remember the AC bracket being in the way but I think I was able to get the compressor off the bracket and out of the way without taking the hoses off when I did an engine transplant.


I still think you should do a push or roll start to see how the engine runs and if it starts when hot. My 220D had low compression and wouldn't start without without the block heater warming the engine. Then it would start as long as the engine was warm. But it would only start with a roll start when it was cold. I was in Nawlins once and parked in a high rise parking lot. I positioned the car so I could coast down the ramp to get it started. Once it got started it ran fine and got 30+ MPG. The rings were damaged when the radiator leaked and I overheated the engine.

I added power steering easily when the engine was out and the PS really worked well.

P E H

is also an option. i have done the rope a dope many times to start reluctant engines.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

t walgamuth,

Push start is a much better option because the push car can back off before trying to start the pushed car. If tethered by a rope or chain, there is the possibility of the towed car running into the back of thetow car if the engine starts quickly or when not expected.

I prefer the hill option where the non running car is towed to the top of a hill and allowed to roll down the hill. But this may be impossible in flat areas so the push start option is second best.

P E H

Jeesh. This thread is reaching oil thread proportions. I was only able to glean some of the posts. IIRC because I am not at my shop where my MB library is, minimum compression is 315 lbs. To be sure you got an accurate reading, be sure the shraeder valve in the compression tester is for diesel and not gas engines. There is a difference. Diesel valves are made wiyh Viton rubber to stand up to the heat. Shraeder valves for anything else will give you lower readings. That said, you need to get the air molecules bumping into each other faster enough when the piston is at the top of the stroke to give each other Indian burns. In other words the temp in the chamber has to be around 900*F when the fuel injects if you want the fuel to burn. Remember diesels are compression ignition motors. (that's for you PEH ) It sounds like a valve job is in order. The oil in the cyls trick usually works if you get an oil can with a piece of hose on it and squirt about a teaspoon down each intake runner. You the wait about an hour as the oil makes a ring around the piston kinda like an oil can does when it has been setting on a surface for awhile. Hope this helps.

Peter

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Auto Zentral Ltd.

Ifsomeone wants to prove they are an idiot by calling a Diesel engine a Diesel motor, so be it. (That's for your Peter).

P E H

thing. yeah but if it doesnt start you have to get it back to the top anyway. and pushing with another benz is dicey (i have done this many times too) because the springs are soft enough for the bumpers to climb over or under the other car and if that happens you can do a lot of damage.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Ok it is definitely a diesel compression gauge. the glow plugs are definitely getting hot. I am pretty sure it will start if some oil is put in each injector hole it is my understanding on the 617 engine if there is more than 3cc of fluid on the piston it will hydro lock I could be wrong about this but I was not sure what a safe amount of oil to put in the cylinders so I did not try this. While the compression on cylinder 1 is quite low in thinking about it I think adding oil thru the injector holes of all cylinders except number 2 would bring the compression up enough to get it to start when I pulled the injector out of cylinder 2 the last cylinder it was as if someone had just dipped it in motor oil it was literally dripping oil. Where he lives even push starting it would have to be done in the middle of the night it is about half a mile to the nearest straight long road that you could push start it on. The pictures posted of this car do not do it justice if I owned it there is no way I would risk push starting it. An important piece of information missing here is the owner is moving in about a week and really just needs to get it to start once to drive to the new house. But if all that oil on the injector from cylinder #2 is indicative of a blown head gasket that is going to cause it more damage or rapid overheating then running it may be a bad idea. fshacker can you post the compression readings for cylinder 4 and cylinder 2 the rear two cylinders that may be of some help and I don’t recall what the were.
Dave S

Compressions were:

#1 = 190 to 210
#3 = 340
#4 = 250
#2 = 290

I guess from what I'm reading, #2's relatively higher compression is a result of the Oil forming a seal, correct?

Thanks!

of the combustion chamber is about 1.6 cu in calculated, so i would not put in more oil than half that amount or .75 or so cu in of oil. i guess that is about a teaspoon... a good healthy squirt from a pump oil can.

in looking at your compression results, perhaps you have washed all the oil off the cyl walls. i know you can do this with a gas engine and it is not good because the cyl in a benz then can stick. my bro did this with his 66 230s many moons ago. not sure if diesel will wash the walls like that or not.

the 340 cyl may have carbon buildup. dont know what would oil the injector like that. you sure it is not gook from outside the injector getting in when you pulled it?

i seem to remember that they will run with 169 psi not sure. but at that level it is hard to start. i think you have enough compression for it to run.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The oil on the injector was not from the outside. It was just like you stuck a half inch of the injector tip in a can of engine oil. I don’t understand what would cause that much oil to get in the pre-chamber like that. The injector was literally dripping with oil. That was the last injector we pulled so it was in as we tested each cylinder and we had another battery jumping the new battery that was in the car so the engine was turning over much faster than normal with three injectors out I don’t know how that could cause that much oil in the pre-chamber. Frankly I am at a loss as to any explanation for all the oil on that injector. Thinking about it the only conclusion I can come to is we were mistaken and it was diesel not oil fshacker what do you think? I think the best thing to do is pull the glow plugs use a baby medicine syringe available at the drug store to shoot some heavy weight oil in each cylinder. Re-install glow plugs Waite 1 hour turn the engine over 1 time using a 27mm deep dish socket on the crank bolt then glow 3 times and try to start it I think it will go.
DHS

if it wasnt jet black it must have been diesel.

your latest strategy thing sounds very good.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Pull all the glow plugs, crank the engine. you should get a cloud of atomized fuel coming out of the glow plug holes. If not, it is fuel probem.

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71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
86 420SEL partswagen
70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
83 280SL euro 5 speed 155K
69 250S newest project 54K