In violation of the holy grail of don'ts

[roctor]

Hello all, When encountering compression resistance in cylinders, I got out the old lug nut tool and turned the engine clockwise. Now the engine will not turn in either direction. Could the chain jump the sprockets or bind in the tensioners? Can this be accessed without dropping the engine? Thanks Roger

[SCWDP911]

what are the details of your setup? If you have an SC, they rotate CCW

[dtw]

Shane - All 911 engines turn clockwise. Some SC distributors turn CCW.

Do you mean that you turned the engine CCW? It is possible that the chains can bind if you do this - but I've never actually seen it happen. Is this an engine in the car and otherwise running fine?

[tcar]

Pull the sparkplugs and see if there's still resistance.

[john walker's workshop]

if you had a collapsed tensioner, it could jump teeth. a good tensioner would not let it happen. could the engine be hydro-locked? oil or gas in one or more cylinders?

[SCWDP911]

Originally Posted by dtw

Shane - All 911 engines turn clockwise. Some SC distributors turn CCW.

Do you mean that you turned the engine CCW? It is possible that the chains can bind if you do this - but I've never actually seen it happen. Is this an engine in the car and otherwise running fine?

Sorry bout that. I guess I was thinking about the distributor. Sorry for the confusion.

[Dixie]

More info is needed.

What was the task at hand? Were you doing a simple valve adjustment? Were you trying to diagnose a problem? Are the plugs in, or out? What's the definition of won't turn? The fan belt slips?

But I'll go out a limb and state the obvious.... A motor that won't turn = a motor with cam timing issues.

[Formerly Steve Wilkinson]

"Getting out the old lug nut tool"? What is he turning? The fan pulley nut is 24mm, the lug nut tool is 19mm. Is there some way to access a crankshaft nut that I don't know?

[roctor]

All, Sorry about first frustrated post. I did in fact turn the counter clock wise. My set up is a 2.7 with 40 ida 3c webers. Hope this helps and thanks for all the feedback. Roger

[Formerly Steve Wilkinson]

Are you trying to turn the upper fan-belt pulley?

[roctor]

addem All, The motor is still in car. I pulled the plugs and probed cyclinders ( no metal bits or gas or oil ) and carbs with magnet. All was clear. Motor was running smooth until this incident. When examining the plugs the were carboned a bit, but maintained proper gap. Roger

[roctor]

Yes, Upper fan pully. I embarassingly turned it CCW until nut broke loose. Roger

[dtw]

How many degrees did you turn it CCW? Did you hear any strange noises? Did you hear any 'chain clicking' while turning it CCW? Did it come to a hard mechanical stop? How much force have you applied in either direction since then trying to break it loose? What type of car/engine have you got, and what type of chain tensioners do you have? What were you trying to accomplish when you did this (that doesn't sound right, I just mean what were you working on?)

If it were me, I guess after I ruled out the 'stupid' stuff, I would pull the chain covers, starting with the left side, to see if anything was bound up. Am guessing I would find a fully depressed tensioner on the left side with the chain bound up somewhere in there. After righting that, I'd put a dial indicator on both cams to doublecheck timing.

To answer one of your first questions - yes the chain can jump the sprockets. It usually does not do this on the intermediate shaft sprocket side when the engine is assembled, just happens sometimes during assembly when you're diddling around with the chains. It could conceivably jump off the cam sprocket, but there's very little room between the cam sprocket and the chain housing. I can't see this happening on a non-running engine; the chain would need some serious 'help' to jump off.

[roctor]

dtw, I was working on the brakes to begin with. After extended lapse in time in starting, I first pulled the coil wire and cranked it to lube engine. Motor turned over fine. It was 2-3 days later when I reconnected coil wire and cranked it about a 1 rev before the engine stopped. While turning engine by hand (ccw) the motor turned and I thought there was a compression release. I hit the starter again and nothing. Thats when I tried to turn upper fan nut and it gave resistance until loosening. There is no way to get a socket on to the crankshaft. Not that I can see without disassembling engine compartment. btw 1977 911s. thanks Roger

[tcar]

Formerly Steve,

In the pcar tool kit the fan nut tool looks like the lug nut tool. I think that's what he's refering to.

[CharlesJones]

Hi Roger,

Just to clarify - you cranked the engine with the starter, it turned about 1 rev then stopped, you turned it CCW by hand a little, tried the starter again and nothing happens, yeah? And what happens when you try to turn the fan nut now (CW!)? You say it gives resistance until loosening - what loosens? You have to turn the fan nut CCW to loosen the fan nut, which is why that tool with the tool with the tooth exists to prevent you turning the pulley CCW when doing so. Sorry for all the questions - just trying to get a clear picture of what happened.

As suggested above, have you tried taking out the spark plugs then turning CW by hand? I've heard it's not unusual for these engines to hydrolock - I've even heard of it happening after heavy rainfall!

By the way, sometimes you have to prevent the fan belt slipping on the pulley when turning the engine over by hand by applying a little tension on the fan belt with a finger.

[dtw]

Originally Posted by roctor

dtw, I was working on the brakes to begin with. After extended lapse in time in starting, I first pulled the coil wire and cranked it to lube engine. Motor turned over fine. It was 2-3 days later when I reconnected coil wire and cranked it about a 1 rev before the engine stopped. While turning engine by hand (ccw) the motor turned and I thought there was a compression release. I hit the starter again and nothing. Thats when I tried to turn upper fan nut and it gave resistance until loosening. There is no way to get a socket on to the crankshaft. Not that I can see without disassembling engine compartment. btw 1977 911s. thanks Roger

I am trying to understand - so the engine WAS turning ok on the starter, or no?

Sometimes when turning CCW on the bench, I have watched the chains as I turned the crank. The left-side tensioner will sometimes depress fully and allow the crank to turn a significant amount out of time with the cams as the chain 'piles up'. The feeling on the wrench as this happens is not unlike what you described as compression release. I'm still not sure what order things happened. Did you get a mechanical stop while trying to turn the engine over on the starter? Is it possible your starter has failed or stuck? Is it possible you dropped a wrench or something down in the crank pulley area? Was your airbox cover off (could something have dropped into your intake?) Were your plugs out when this happened, could something have dropped into a spark plug hole?

Could be worth testing your starter before pulling chain covers. By the way, pulling chain covers is possible in the car, the biggest pieces you need to remove are the muffler and the rear tin. Tim Walsh and I successfully replaced a cam seal, retimed the engine, and had the car back together in a few hours once. It isn't that bad.

One other thing - do not pull your coil wire and crank the engine. This is a good way to damage your ignition. A better way is to simply pull the spade connector off the CDI box itself - the ignition will not function when this wire is pulled.

[roctor]

Once again Im mistaken. I thought the fan nut wrench was lug nut tool as well. When refering to loosing up I meant the fan nut, not the engine. Roger

[tcar]

OK... so...

When you turned the fan nut, did the engine turn CCW or did the belt slip?

Can you turn the engine CW w/ the wrench w/ the plugs out?

Will it turn w/ the starter w/ the plugs out?

[JP911]

Possible that your starter took a crap? Dead battery? Car in gear while trying to turn crankshaft?