Crankshaft not turning clockwise

[michaeljchn]

Hey guys,

I'm in the middle of a vanos rebuild and Ive followed all the youtube, beisan, dr.vanos procedures out there to try and get my timing right but its always off on the intake cam side by 2-3mm. But this is a seperate issue...

As I was loosening the hub bolts to try and adjust the timing, i was turning the crank and suddenly - it feels like the entire crank has seized? I can't turn it clockwise any longer and its not moving anything if i try. I can turn it CCW but thats not doing me any good.

I was loosening the hub bolts (intake and exhaust) and turning the crank to rotate the hubs to the other side to loosen the bolts on the other side and then it froze. I can no longer turn the crank.

Could anyone advise?

[pynacl]

Super silly question but is the car in gear? Suppose if you tossed it in 1st at any point to function as an e-brake that would stop it from spinning freely. Otherwise I can't think of any other reason besides something physically contacting that shouldn't be. Also assuming the spark plugs/ignition coils are removed?

[liam821]

Try removing the spark plugs, then you won't be fighting the engine's compression.

[michaeljchn]

Yeah, car is in neutral - spark plugs are all removed. And im stumped as well, it was rotating freely until it wasnt.

Could I have somehow contacted the valves and the pistons due to the timing being completely out of whack?

[heinzboehmer]

If some of the hub bolts are loose, then the cams might no longer connected to the crank. Be careful, it might have stopped turning because you're hitting valves.

Turn the crank a little bit counter clockwise and check if the cams are turning too. If they're not, you either need to re-torque the hub bolts to reconnect the crank to the cams or turn the crank a little and then the cams a little.

Remember that the crank turns 2 rotations for every rotation of the cams. So, if you leave the hub bolts loose, you'll have to move the crank twice as much as the cams, in terms of angular displacement.

[sapote]

I was loosening the hub bolts (intake and exhaust) and turning the crank to rotate the hubs to the other side to loosen the bolts on the other side and then it froze. I can no longer turn the crank.

With the hub bolts loosen, then turning the crank will not turn the cams in synch; therefore, crank and cams are out of timing and piston is hitting the valves. Slowly and gently turn the crank CCW to get back to crank/cam in synch.

Your goal is to get crank to TDC compression and the cams #1 lobes 45 deg pointing at each other.

Never turn the crank with hubs bolts loosen unless you know what you're doing.

[michaeljchn]

Shoot i guess my worst fears are confirmed - the hub bolts were loose so the cams might have disconnected from the crank and now im making contact with the valves.

When i turn the crank counter clockwise, the cams do rotate. its when i turn it back over clockwise where it turns until a point where it completely seizes up.

With that being said, how could i get it all back aligned? Turn the crank CCW, tighten hubs, then try to turn the crank CW again?

[michaeljchn]

With the hub bolts loosen, then turning the crank will not turn the cams in synch; therefore, crank and cams are out of timing and piston is hitting the valves. Slowly and gently turn the crank CCW to get back to crank/cam in synch.

Your goal is to get crank to TDC compression and the cams #1 lobes 45 deg pointing at each other.

Never turn the crank with hubs bolts loosen unless you know what you're doing.

Yeah, im feelin pretty bummed about my competency at the moment lmao.

But live and learn I guess. Im trying to figure out how to get them back aligned? If i turn the crank CCW how would i know that the crank and cam are back in sync? I assume when i turn the crank and the cam turns, then they are in sync?

[Arith2]

If you're off, find TDC for the crank and pin it. See how far the cams are off when using the timing bridge. #2 lobes should sort of be facing each other. Beisan instructions have a picture. This won't be too difficult to fix.

[pynacl]

Yeah, car is in neutral - spark plugs are all removed. And im stumped as well, it was rotating freely until it wasnt.

Could I have somehow contacted the valves and the pistons due to the timing being completely out of whack?

That is strange. Although even if it's a piston on valve contact, I feel like rotating the crank by hand and stopping at a resistance point is unlikely to cause any serious damage. I haven't done a VANOS rebuild before so hopefully someone with more knowledge can chime in, but my understanding was that the crank stays locked at TDC and the cams locked using a bridge tool during the process. If it were mine, I'd see if I could very carefully rotate it CCW to TDC and get a level reset and double check the timing procedure.

edit: people with more knowledge have chimed in

[michaeljchn]

Quick update - i ran back out to my car and just turned the crank CCW (i know its the wrong way, hopefully it didnt mess anything up) and got the crank to TDC. Locked it with the pin, tightened down the hubs, and rotated it back clockwise and now it spins freely.

[heinzboehmer]

Nice

[sapote]

Quick update - i ran back out to my car and just turned the crank CCW (i know its the wrong way, hopefully it didnt mess anything up) and got the crank to TDC. Locked it with the pin, tightened down the hubs, and rotated it back clockwise and now it spins freely.

Great. Now you just need to set the vanos timing correctly

[digger]

And then do a compression and/ or leak down check to see if the valves are bent

[maupineda]

And then do a compression and/ or leak down check to see if the valves are bent

No way he bent the valves by turning the engine by hand