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911sc engine will not turn over.

New member and first post.

I have a 1981 911SC and the motor will not turn over, it has not been started for two years and it is the first time I have missed firing it up for a summer last year and now it will not rotate at all. I tried to get it to rotate by putting it in 5th gear and pushing it to see if that would snap it out of its seizure but that did not work, just dragged the rear tires and now I am concerned!! Anyone have any advice on this I would much appreciate it.

It is kept in a garage but it is not heated and we live in a rainy area in British Columbia and it seems to have seized up somewhere?

Old 05-26-2025, 05:00 PM
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Where in BC? And how did you rotate the engine?
From the crank? More info on the engine will be helpful.
Old 05-26-2025, 05:14 PM
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We are on Saltspring island, I put it in fifth gear and pushed the vehicle but the rear wheels didn’t turn, I just dragged the car. The engine has been running every year except last year, we aren’t home during the winters and due to a death in the family I didn’t get a chance to start it last year, this year it feels like it’s seized up, original engine, 3 litre with 130k on it.
Old 05-26-2025, 06:09 PM
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Damp climate, long period of sitting idle. I would make sure the clutch has not bonded to the flywheel. Seach function on forum should provide solution. Good luck.
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Old 05-27-2025, 03:04 AM
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If you put the car in neutral and turn the nut on the fan pulley CW, does the engine rotate? It may be necessary to apply some tension on the belt with your finger to get it to rotate.
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Old 05-27-2025, 04:25 AM
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Sounds hydrolocked. Pull the spark plugs and crank it.
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Old 05-27-2025, 05:31 AM
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I agree with Shooo, pull the plugs and try and rotate it by the crank nut. No more 5th gear bumping, you will only damage things.
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Old 05-27-2025, 05:55 AM
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Thanks for the tips all!

I don’t think it’s the clutch bonded to the fly wheel because it should still turn over if the car is in fifth gear while pushing it, similar to jump starting on a hill so I have eliminated that, I pulled two spark plugs to see if there was an oil build up in the cylinder and there wasn’t anything in the two cylinders but there is also another four cylinders so it could be hydro locked ,I will check all plugs and try rotating the engine by hand to confirm that.

Any other ideas?
Old 05-27-2025, 07:18 AM
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I agree with pulling the plugs as a first step. you may want to try to spray some lube in the cylinders too, to help break free any corrosion or bond between the pistons and cylinders. if you can curve the straw so that you can direct the spray at the top of the piston and let gravity pull it down along the piston/cylinder edge.
Old 05-27-2025, 08:32 AM
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Like everyone's suggestions.. I would start on turning the engine
while in neutral by hand and you can feel the pistons compressing too.
Then check fuel ( pump) if working, check for sparks and you should hear cdi buzzing.
Check unmetered air ( pop off valve if you have) blown airbox maybe, check vacuum leaks.
Check starter too. Of course you will check all of the above once you confirmed the engine turns.
Once you get it started..check timing.
There's a lot of little things to check for sure but start with the common ones.
Too bad you're not close to me, I would help you.
Good luck.
Old 05-27-2025, 08:42 AM
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If all the obvious check out I’d take a look at the cam chains, tensioners.
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Old 05-28-2025, 05:15 AM
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I'm with Tony and Brighton: pull the plugs and make sure it isn't hydro locked. After sitting for two years, enough oil could have drained down from the tank and into the case and past the piston rings to lock up a cylinder or two.

Did you try to start it before realizing the engine was locked? What condition is the battery?
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Old 05-28-2025, 10:58 AM
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Battery is new and oil hydro lock could be an issue as the oil level was very low in the reservoir and as usual some ran onto the garage floor, I will try to get to it this weeekend and dig around. I have also heard of starter lock issues so I will target that also. Thanks everyone!
Old 05-28-2025, 05:57 PM
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Pulled the plugs and the two front cylinder spark plugs were wet with oil, visual inspection showed oil in the cylinder.
I drained all the oil from the motor pan and the sump tank and let everything drip out for several days, once that was done I could then turn the motor using the fan belt. Turned the motor with the plugs still removed for several revolutions with the starter but nothing else came out, installed the plugs after cleaning them and all good to go!

I guess the oil loss was the clue, where would it all go?? Well it went into the cylinder and hydro locked the motor in the front two cylinders and the car being nose low by a bit for storage filled them up.
Old 06-26-2025, 05:06 PM
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Excellent. This is such good news. By that I mean not a catastrophic engine failure.

Old 06-26-2025, 11:34 PM
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