Y'all do what you like.
A) If the force required to turn the engine exceeds the torque spec of the crank bolt, it's seized for good.
B) If the crank bolt breaks without a lot of force, it was damaged prior to your attempt.
C) If you think it's expensive and troublesome to replace a broken crank bolt, imagine the cost and bother of replacing broken rings and/or flywheel ring gear.

You've already put oil in the cylinders, now all you need to do is put a wrench on the crank bolt and slowly work it back and forth to free it up, if it's not seized. I contend it is still best to do this, even if the starter motor would turn the engine, because slow and careful will allow that oil you placed in the cylinders to spread more evenly over parts that have not moved for more than a decade.

I'm done.

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1989 300 SEL that mostly works, but needs TLC

and if the starter goes bad over a few bumps, it is about gone already too. ditto for the ring gear.

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.

I agree with several of these points, namely, a,b, and c. I really think that turning the crank bolt will work without an enormous effort. This bolt is rated to be torqued to several hundred NM and if this breaks, the starter surely wouldn't have started it either - but it might knock a tooth or two off of the ring gear. I'm not even certain that a normal person could generate the kind of force needed to break an undamaged bolt with a 1/2" breaker bar, unless built like Popeye.

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86 560SL
With homebrew first gear start!
85 380SL
Daily Driver Project

http://juliepalooza.8m.com/sl/mercedes.htm

we have a poster who broke one.

do we have any posters who have ruined starters this way? or ring gears?

i like the starter method because it is using things in their designed way. it is relatively gentle and a small jar of stuck components is a good way to get them loose. as i have stated... i have done it several times with some success... never a problem. i have friends who have done it also.

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.

Exterior...

Interior...

Engine (as of this week)...



Amid all of the debate I want to thank everyone for posting their experiences and opinions.

Now that's just ignorant. There is nothing 'gentle' about using the starter. Electric motors develop maximum torque at 0 (that's zero) RPM. Smacking stuck parts with maximum torque is a good way to test their shear strength, though.

__________________
1989 300 SEL that mostly works, but needs TLC

Using the starter is a risk. If this was a '82 Chevette then ok, but I wouldn't risk it on a handbuilt 280SEL 4.5. The last of the real good cars.

I doubt you are going to break the crank bolt. Unless you use a 3/4 inch impact on it. I would remove both valve covers and replace all of the plastic tubes that oil the cams, just to be safe. It wouldn't hurt to use some engine assembly grease on the cam lobes. I would drain the old oil out and change the filter also. Oil capacity is around 9 quarts. Pulling the plugs and soaking the cyls with a light oil is a good idea. I would also make sure that the rubber fuel lines below the air cleaner and leading to each injector are sound. Many a D-jet v-8 has caught fire because of fuel leaks here.

I did. On a 190SL. I had to replace the starter drive AND the ring gear on the flywheel. Thankfully, this was in 1977, when parts were still affordable for these cars. Sure was alot of labor. I later freed up the engine using the crank bolt.

but stand corrected.

i withdraw my recommendation.

i probably would do it my self but wont after this recommend it any more.

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.

That engine compartment looks pretty grim IMHO. Lets keep in mind the guy never said the thing is actually seized. So this could all be hypothetical, at least for this car. I was told the best way to unseize an engine is remove the plugs and pour Coke/Pepsi in and let it sit awhile so the phosphoric acid eats the rust!! They didn't say how to get the Pepsi back out however... I have cleaned some light rust this way. Pretty scarey. Might be one for Myth Busters. Along with the spontaneous combusting hay barn.

Mike

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

First remove valve covers and thoroughly inspect. If cam lobe surfaces have rust--remov them and clean off and polish off the rust BEFORE turning the engine.. Douse every moving part with Marvel Mystery Oil (red and black can at O'reillys or othe rparts houses). Be sure valve stems are clean (not rusted or seals will tear up immediately.) Tap down on all the valve stems to try and move them. They should ALL move when you hit them--even the ones fully 'open'. This step will help avoid "piston hits stuck open valve head." If a valve is stuck open, soak with MMO, heating the spring and valve stem with hot air (hair dryer) allow to soak overnite. nextday , tap down repeatedly on valve stem to try and loosen it. They will generally snap free right away using this method.

2nd-remove spark plugs and pour 1 oz of MMO in each cylinder. Leave at least 48 hours B4 trying to move the engine. 2 weeks is better.

If fuel injected--remove the injectors and ditto on the MMO addition -leave the plugs and injectors OUT until engine is free turning and you are ready to fire it up.

Change the oil--add it HOT if you can (+/- 250F). Add 1 QT MMO to the sump with the fresh oil.

I presume no coolant in the engine--add fresh HOT (180 F) 50/50 mix to heat up the cylinders and improve MMO solvent/soak

remove all belts. Disconnect drive shaft (tranny might be stuck)

Using a 'remote starter switch' connected directly from battery to the starter relay Bump atiny bitwith the starter and fresh battery while you are watching carefully. (check wiring condition first --no fires please. Be sure fuel pump fuse is removed--no gas flow until ready to fire it up. Check to be sure the valves are following cam lobes--not stuck open. A stuck open valve will hit the piston head and you won't like the resulting mess.

If the engine turns--STOP after a few (<5)seconds. Check everything out--re-lube cams and valves, add more MMO to each cylinder. GOT TO HAVE LOTS OF LUBE IN THERE

If all seems OK, crank until oil pressure comes up no-more than 30 sec though

Stop 5 min and let starter cool, repeat until good oil flow to cams established.

it sounds very thorough.

i would not hesitate to do it. it is pretty much what i have done in the past except for the adding hot coolant and hot oil.

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.

Wow, very thorough and a great description for the starter method. I'm sure I can do it all except for the 'remote starter switch' although I bet it's very simple.

EDIT: is this what I would need, http://www.glassmaster.com/controls/rs1.htm ?

Freshly charged battery
Pulled spark plugs
Pulled coil wire
Removed the fuel pump fuse
Readied the fire extinguisher
And turned the key...

And my 4.5 is not frozen!

The starter makes a lot of noise so I can't hear the engine chugging but my inner fenders are sprayed with Marvel Mystery Oil (and so is the white rag I left on the fender). I can only assume that the pistons are pumping the MMO out through the plug holes.

My next step is draining the gas tank and radiator, and inspecting the ignition system for frayed wires.

after thinking about it.

back in about 92 i got a 51 caddy free that had been sitting in a carport for 20 years or so. when i rescued it the carport had collapsed on it. starter and oil and patience only.

then about 2000 i did the same thing with a 53 studie that had been sitting for about 20 years. got it free. later sold it to a friend cause it got all moldy inside after sitting in my damp infinished basement garage. his high schooler got it running and is using it now.

my old 280e ex ralley car, which i bought back after about ten years, and after it had been underwater literally, i tried it and it did not work. it is still tight as a drum and waiting teardown by my favorite machinist.

so far i havent damaged anything. maybe lucky.

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.