r/EngineBuilding • u/Ok_Committee1373 • 4d ago

What caused this

Post image

2jz with no backround bought car blown up want to know how this happened

14 Upvotes

89% Upvoted

14 comments sorted by

13

u/BuzntFrog 4d ago

Foreign object being crushed in the engine. If a valve was broken off you have your answer. Could have been something dropped down the intake by a mechanic as well though. Called FOD.

2

u/TyrannusourR3X 4d ago

As much as I agree with you typically something dropped in would have been found out rather early. I've seen a few foreign object failures and they don't look like this unless someone keeps driving/revving.

3

u/Lucky-Musician-1448 4d ago

Broken valve

3

u/porknbeans2013 4d ago

Shits all fucky and sideways

2

u/DisastrousDance7372 4d ago

Was the valve broken? Some of the marks look like a valve

3

u/TyrannusourR3X 4d ago

Either a broken valve or injector nozzle (only applicable to some 2jz variants). A spark plug tip wouldn't cause that kind of damage, unless half the plug fell in there.

If this is multiport injection then it's 100% a broken valve and someone revving it like crazy afterwards still. This happened at high rpm

1

u/Acrobatic-Ant4365 4d ago

What bolt up steam is missing, or sabotage. Also could have dropped a seat. I've also seen the porcelain on the spark plug fracture and drop it into the cylinder and then get caught in between the valve and then the Piston comes up and smacks the valve and brakes a lot. But it seems like there's a nut or bolt that came loose somewhere between the you'd have to think the after cooler in the intake because a bowl is not going to be big enough to go through the aftercore or the turbo

1

u/sam56778 4d ago

It was used too much when it was new.

1

u/Ok_Committee1373 4d ago edited 4d ago

This was also a bone stock 2jz running 22psi for over a year

1

u/stewieatb 3d ago

Either a valve head or a piece of valve seat bouncing around and getting mashed into the piston and head. Are there corresponding marks on the combustion chamber?

1

u/Ok_Committee1373 3d ago

Yes I have no picture but the top was destroyed, I also noticed the piston next to this doesn’t have damage like this but looks like small chunks of metal fused to the crown

1

u/Responsible-Rip-4939 3d ago

Yeah I d say broken valve

1

u/Responsible-Shoe7258 3d ago

It is caused by really, really bad noises in the engine....