1HDT Seized?

[Classic85]

Completed the timing belt change( Not 1st timing belt) went to turn the motor by hand to ensure everything was going well and the motor would not turn by hand (pry bar)
Tried turning by hand again, it felt tight so I pulled more, used more force, something gave way. I crack, a release, something. Like a tough bolt releasing from torque.

I buttoned up the job and started the vehicle.

Video result

Checked the job over and all is correct. Placed transmission in neutral, transfer case out of gear, removed glow plugs (need new glow plugs)
Tried turning by hand again. Now i have 1\2 turn on the crank pulley and that's it, it will not move either way any more.

What would prevent the motor from turning by hand yet still allow the motor to start and run? And based on the explanations above why is it out of time?
Trying to get the motor to TDC to ensure i haven't slipped a cog.

 

[Hulsty]

Bent valves?

 

[Loober]

Yea you are probably interfering with the valves, you don't have enough strength to overcome it by turning it manually but the engine has enough power to turn it over. From the video it does sound like something is making contact. That initial crack you heard was probably contact with a valve that broke loose. Unfortunately you are looking at a complete engine rebuild or at least a tear down to see what is damaged.

On these motors, its not just the TDC mark on the crank pully, its also the mark on the camshaft and pump spocket that all must be aligned, the camshaft must have moved in between and put everything out of alignment.

 

[Classic85]

Bent valves?

Yea you are probably interfering with the valves, you don't have enough strength to overcome it by turning it manually but the engine has enough power to turn it over. From the video it does sound like something is making contact. That initial crack you heard was probably contact with a valve that broke loose. Unfortunately you are looking at a complete engine rebuild or at least a tear down to see what is damaged.

On these motors, its not just the TDC mark on the crank pully, its also the mark on the camshaft and pump spocket that all must be aligned, the camshaft must have moved in between and put everything out of alignment.

Yea you are probably interfering with the valves, you don't have enough strength to overcome it by turning it manually but the engine has enough power to turn it over. From the video it does sound like something is making contact. That initial crack you heard was probably contact with a valve that broke loose. Unfortunately you are looking at a complete engine rebuild or at least a tear down to see what is damaged.

On these motors, its not just the TDC mark on the crank pully, its also the mark on the camshaft and pump spocket that all must be aligned, the camshaft must have moved in between and put everything out of alignment.

Hulsty, that was my 1st thought as well.

Usually this motor runs extremely smooth. No valve train noise or shimmy. The video shows me that something is not right.

I never checked the crankshaft timing marks. However, the cam and pump pulleys where set to BDC why then would there be contact with the valves? Even if the cam shaft moved a bit there should still be no contact.
For s***s and giggles lets assume that this is the case, that they are out of alignment. What is best course of action to reset them all to correct position given the hand turning issue?

 

[Loober]

First pull the timing belt cover off and get the crank pulley to TDC, camshaft gear has both a BDC and TDC mark, see if they align on the TDC. If not, that's def your problem. To get it back in alignment, you'll have to pull the main timing cover and follow the FSM to align the main timing gears behind there. That in it self is a lot of work, I would just pull the head and check the valves out. At that point the damage is already done.

 

[roscoFJ73]

What would prevent the motor from turning by hand yet still allow the motor to start and run? And based on the explanations above why is it out of time?
Trying to get the motor to TDC to ensure i haven't slipped a cog.

Who knows whats happened. But its obvious something was wrong before you started it. Never assume everything is good without checking the marks. And never start the engine if you cant complete the rotation by hand.
You might be able to slide a boroscope down the glowplug holes to look for valve/piston damage to get an idea if there is damage.

 

[Classic85]

Bent valves?

I slipped a cog on the timing belt (still not sure how that happened)
Once I released tension on the tensioner the cam snapped back into place. This allowed for the motor to turn by hand. Once that was accomplished i removed the timing belt, got all the pulleys to the correct marks, replaced the timing belt.
Tensioned it up turned by hand and all was smooth.
Buttoned up the job, started motor and she ran smooth as glass.
Thanks for all the oppinions.

 

[Hulsty]

Leakdown test would be a good idea

 

[roscoFJ73]

If the pistons have dents in them , they may fail and let compression gasses enter the lower half of the engine. This tends to blow the oil pan off.

 

[Classic85]

Did a compression test.

1 Dry 462 Wet 540
2 510, 510
3 480, 480
4 460, 480
5 470, 500
6 468, 490

Leak down tester was a fail, the tool just wouldn't work. i think with these numbers i am in good shape.

 

[lelandEOD]

… very strange. Bore scope time?