How could it seize?

[Macspsi]

Here's the story, recently replaced headgasket, water pump, timing belt, and put in arp head studs. I've been easy on it for awhile since I put the 16g on since I did not have a tune, but I was only running 12lbs to be even more sure I wouldn't hurt it. Last week I was coming home, I slowly eased into it and watched it build to 10lbs and it was pulling pretty good and then it blew a coupler off. Thought that I had tightened it up good enough. It cut off of course and I just coasted it into my driveway and let it sit because I had to go back to college. Yesterday I went to start it, and it didn't sound right almost like a clicking when the motor was turning then it locked up. I have no idea what could cause this, good oil pressure, fresh water pump. I know it couldn't have sucked up a rock when the coupler came off because it was on the j-pipe so that would be next to impossible to happen. I also popped the valve cover off to check everything there and everything looks perfect. Tried to turn it by hand and it would not turn. Please help me diagnose this.

 

[Wil_Own]

Take your plugs out and try to crank it.You might have to drop the pan and start looking around .Was it raining?

 

[Macspsi]

Alright, I'll do that. No it wasn't raining.

 

[BogusSVO]

Check your timing markes and make sure the belt did not skip a few teeth

 

[Techmonster23]

Did you remove the plugs when you went to turn it over by hand?

 

[Macspsi]

Just removed plugs and tried to turn it by hand, and it barely moves. Timing is good.

 

[dsmreck]

have you dropped the pan or drained some oil?

 

[DSM1G90]

and it barely moves

Quirt some light oil down the bores to slick up the cylinder walls when you try to move it. See if it will free up the pistons some...

Good luck on your find - DSM

 

[anticsak]

Check your timing markes and make sure the belt did not skip a few teeth

how do you get it to tdc, and is it different for the 420a..

 

[Macspsi]

Found out why my motor locked up....

 

[pcarroll32]

Ouch!!!

 

[pauleyman]

Curious how you said timing was okay but that happened. If that were true then what really did happen? That looks like mechanical damage when valves hit pistons.

 

[Techmonster23]

My god that is some catastrophic damage....

 

[guamboyeli]

I think we all cringed when we saw the broken valves

 

[jayson427]

Yeah ouch is right my friend i feel the pain from here. But how? I don't see how you could of been driving it (obviously if the timing was that bad to break all them valves you would of known from the first start up) just fine then you pop a coupler with this result? It had to jump time or bad clearances. Hope you get her fixed up man good luck!

 

[Colt4G63 also]

That looks like a lot of rust in cylinder #4 too.

 

[Macspsi]

Think the rust will be a problem? Buying another head this week. This is just another example for all the newcomers when you want to turbo upgrade SUPPORTING MODS!!! I will be doing a build thread soon just a mild one though.

 

[JusMX141]

Think the rust will be a problem? Buying another head this week.

I think rust is the least of your concerns if you're planning to use this block again given the fact that the pistons hit the valves hard enough to break them. Cracked pistons, pinched ring grooves, and bent rods would be right up there.

 

[Macspsi]

well i don't know if the rod is bad, but idk if you can tell by turning it by hand with the head off, but when my dad did everything seemed okay block wise.

 

[boost97gst]

Id most definitely have the block checked by a machinist before i dumped a penny on anything else. You may be in for a full build. That is brutal.

 

[Bo0sTdTsI]

Damn that sucks bro! Sorry you had that happen man that's not my car and it hurt me seeing those pics, at least note you can build something to your liking now.

 

[Macspsi]

Well I'll also be fine if i need another block, my brother has one that he would lend me to use i would only need a head. But I'll still get this one checked.

She'll be back though, as all of you probably know or will know every time dsm breaks down it comes back even stronger!

 

[untouchablecc]

Im sitting at work and I said "damn" out loud. Thats just painful. Your into a full rebuild at this point or looking for a running engine.

 

[Macspsi]

Yeah just trying to stay positive hit me kinda hard. But I guess I'll start taking the bottom end out, and also look for our spare bottom end and take them to a machinist and see what they say. Mods you all can resolve this

 

[DSM1G90]

I'd just plan on a new shortblock with that much internal damage...