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NukeKS14 · 12-26-2020, 08:25 PM

The things you're asking aren't mutually inclusive;

I think you're getting confused between few separate things here;

An interference engine is a type of 4-stroke internal combustion piston engine in which one or more valves in the fully open position extends into any area through which the piston may travel.

So, if your timing belt/chain were to break/skip teeth, then you're going to have some valvetrain damage because some of the valves are going to be extended into the path of the piston at full travel (top dead center).

A non interference engine does not have the valves extend into the path of the pistons so a broken/skipped timing belt/chain doesn't necessarily mean a damaged valvetrain.

^None of that has to do with the headgasket blowing or being in-tact though.

Blown headgaskets can be in a number of different locations and for a number of different reasons. It also doesn't necessarily mean you're going to have a damaged rotating assembly. You could blow a headgasket between cylinders and all you'll have is low compression on those cylinders and a rough engine. You can blow a head gasket between an oil and coolant passage and wind up with milky oil that's overflowing. You can blow a headgasket between a cylinder and a coolant channel and wind up with overheating and boiling/aerated coolant. It really depends.

A siezed engine is a completely different thing altogether still. If the engine is siezed, you've most likely overheated main/journal bearings and or rod bearings and you're gonna have to tear the motor apart and have it inspected to determine the extent of the damage and what'd be required to get it in working order again.

I'd say if you blew a headgasket and continued driving the car until the engine siezed, it's PROBABLY toast and you'd do best to just find a replacement.

(I realize I didn't actually address bent rods and/or damaged rotating assy beyond the bearing side of things. Bent rods/damaged pistons don't result in a blown headgasket but may result in valvetrain damage if parts of the piston/rings are scattered into the combustion chamber.)

12-26-2020, 08:25 PM	#2
NukeKS14 Zilvia Member Join Date: Apr 2019 Location: KS Posts: 221 Trader Rating: (1)	The things you're asking aren't mutually inclusive; I think you're getting confused between few separate things here; An interference engine is a type of 4-stroke internal combustion piston engine in which one or more valves in the fully open position extends into any area through which the piston may travel. So, if your timing belt/chain were to break/skip teeth, then you're going to have some valvetrain damage because some of the valves are going to be extended into the path of the piston at full travel (top dead center). A non interference engine does not have the valves extend into the path of the pistons so a broken/skipped timing belt/chain doesn't necessarily mean a damaged valvetrain. ^None of that has to do with the headgasket blowing or being in-tact though. Blown headgaskets can be in a number of different locations and for a number of different reasons. It also doesn't necessarily mean you're going to have a damaged rotating assembly. You could blow a headgasket between cylinders and all you'll have is low compression on those cylinders and a rough engine. You can blow a head gasket between an oil and coolant passage and wind up with milky oil that's overflowing. You can blow a headgasket between a cylinder and a coolant channel and wind up with overheating and boiling/aerated coolant. It really depends. A siezed engine is a completely different thing altogether still. If the engine is siezed, you've most likely overheated main/journal bearings and or rod bearings and you're gonna have to tear the motor apart and have it inspected to determine the extent of the damage and what'd be required to get it in working order again. I'd say if you blew a headgasket and continued driving the car until the engine siezed, it's PROBABLY toast and you'd do best to just find a replacement. (I realize I didn't actually address bent rods and/or damaged rotating assy beyond the bearing side of things. Bent rods/damaged pistons don't result in a blown headgasket but may result in valvetrain damage if parts of the piston/rings are scattered into the combustion chamber.)