Cranking issue

[n/a]

I recently bought a 68 280SL, low miles, AT. The car had been parked for about 5 or 6 years. The previous owner swore up and down that they started the car a couple times a year while it was parked, but added that they weren't able to start it (with just the help of jumper cables) the last year or two.

I have begun working on the car and can't get the car to crank. The starter motor would engage, but would not turn the engine. So i removed the spark plugs, squirted some WD-40 into the cyliners, and used a 27mm socket and a breaker bar to try to manually turn the crank. No luck. What to do next? (I am an novice mechanic with shallow pockets).  Any suggestions would be much appreciated.

Also, is it possible to torque "too much/hard" on the crank bolt and do damage to the engine?

[knirk]

Chuck,
To start the elimination process I would take off the valve cover and try to move the camshaft, just gently, by use of the sprocket bolt. There should be enough slack in the chain for just a little movement.

If the camshaft moves, I would squirt a lot of thin oil into the cylinders and let it work a while before trying again.

If this doesn't work, I am afraid you need to start a more serious operation involving some dismantling of the engine. Even if you get it turning I would be reluctant to run the engine since you may inflict damage to either the cylinder walls, crankshaft or big-end bearings - and you wouldn't know where it was stuck.

Per G. Birkeland
69 280 sl aut 834
Norway

[blairwag]

Check,
I agree totally with Per.  One important thing that you really MUST learn, before attempting to start the engine, is what was stuck.  This is why you MUST address this via a process of elimination. Don't do 7 things to the engine, and then try to turn the crank shaft. Do one thing at a time. Take your time, and take it slow. If you resolve the issue, and it's just one thing, then you'll have a little more confidence that the engine won't self descruct when it is started.  This, ofcourse assumes that only one thing is "stuck", and that you don't have a lot of scoring of the cynder walls already.

--
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William Blair Wagner: blairwag@earthlink.net
Education is not always knowing the answer,
...but rather knowing where to look for it!
1971 280SL US Automatic
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[rwmastel]

I'm a novice mechanic as well, but well read on this forum.  It's down the road for you, but I would strongly recommend that once you do resolve the "stuck" issue, that you really clean, replace, rebuild, and/or bench test all components of the fuel system before trying to start the car.  Search this forum for key words like "fuel injection pump", "fuel line", "rebuild pump", "fuel rust", "fuel tank", "fuel rate", and so on.

Best of luck to you!

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[isofast]

Chuck B a guy from this board told me that for a stuck motor you can fill with diesel fuel and let soak for two or three days. Do not overfill as it will spill a greasy grimey mess out of the dipstick tube on to your garage floor! Dont ask me how I know! Also always turn in normal rotation as you can damage and slack timing chain components...so I am told. I did this and it worked! Turn a little each night by hand until it spins free then redrain and refill with engine oil. It will take two oil change's to get rid of the diesel and gunk that is kicked loose. Do this and also like Rodd has cautioned make damn sure your fuel delivery system are all free of gunk and varnish before firing. Good luck and keep us posted.
Ernie

First Place AACA Show Winner 350SL July 2003
I love low mile Mercedes.
1969 280 4spd Papyrus White