Engine locks up on stand....Ughhh

[NoYouRelax]

I really hate to visit the rebuild forum as I am just doing my clutch and chasing leaks but here goes.......

While prepping for a valve adjustment, I felt the engine mechanically lock as I turned the crank. I was able to rotate it freely about 270 degrees. I turned the engine on the stand to the cylinders vertical position and the locking cleared. When I turned the engine back to horizontal, the rotation locked again.....

Time to map out which cylinder is creating the binding and get a borescope. I noticed some threads/posts and many folks in the engine rebuild forums talk about chains bunching up. Not sure mine could as they are under good tension.

Note that the spark plugs have not been remove but the CIS and valve covers have been removed. I can only hope for something magnetic for now....perhaps a washer down the intake port?

The engine currently turns freely but I hope I can find out why or what for and maybe recreate that binding situation. Nothing to turn a blind eye to for sure.

Razzzmm Frazzmmm!!!

[NoYouRelax]

Is there a chance I caused damage even though I did not force the crank once I felt mechanical binding?

[BURN-BROS]

You may have dropped a nut or washer down the intake port.

You need to provide more info.
Engine out of car?
on a stand?
stock flywheel?

[NoYouRelax]

Aaron, I hope I can find the culprit tonigh. I will do a borescope inspection this evening and sweep with a magnet and use some gravity as well. Even since the engine rotates freely now, I need to find the cause. I will remove the exhaust and look there too or snake the borescope in there.

The engine is on a stand, the stock flywheel has been removed and is no good. It has been cut once and there are new surface cracks. DOA at machine shop.

[JJ 911SC]

Use a wet/dry shop vac before doing any else.

Make sure the canister is totally clean before you start.

[BURN-BROS]

If it's a washer it can move around and free up intermittently.

[boyt911sc]

Bill,

My bet is a stray nut or washer from the intake runner that fell in during the CIS intake runners removal. That is a common blunder committed by some people including myself. Do not despair. Identify which cylinder is up close to the dome and inspect. A suction hose from a shop vac would do the trick. Clean up the shop vac before using it so you'll know if you got the 'object' out.

After you determined which cylinder is affected, slightly turn the crankshaft counter clockwise to release the pressure on the 'object' and apply suction to the spark plug hole. Keep us posted.

Tony

[JohnJL]

Are your cylinders still on?

[NoYouRelax]

Crisis averted... I found a washer where the #3 cylinder spit it into the exhaust. I will inspect that valve soon even thyough I did not force anything. wheeww

[BURN-BROS]

Glad you found it. You should be fine.

[fanaudical]

Even though you found something, I wouldn't assume that was "it". A buddy of mine once dropped a nut and washer down an intake, retrieved the nut, and located the washer the hard way...