Hey Guys, sorry for the newb question... but like the title says,
"What is a sucked valve?" and how does that happen?

 

I don't think it exists. Are you referring to a valve that controls vacuum?

 

I've never heard of it. Where did you learn this term? Are you possibly mishearing it from the term "stuck valve"? Which is when a valve stays open regardless of the camshafts position.

 

OK Ill give it a shot.
The intake and exhaust valves are held closed by a very stout spring( valve spring) If due to age,heat, or high rpm this spring should break it would allow the valve to drop down into the combustion chamber.For an example Lets say its the intake valve on a 22r with 300,00 miles,overheating and revved to 7,000rpm (extreme I know!)
The spring is doing its best to compress as the rocker arm pushes down then tries to expand back to close the valve, eventually it will break.IF this happens during the intake or power stroke, the vacuum created by the piston traveling down could SUCK the valve into the combustion chamber.The term "sucked a valve" is just a way to say "My valve train just broke and its gonna cost me an arm and a leg to fix!"
With the example I gave many other things will break . Heat and or age can cause a valve spring to break during normal operating conditions. Also the keepers could fall off which would allow the valve to DROP into the chamber.Regardless of the term used , its not good when it happens to a overhead valve engine.If your dealing with a flathead engine or L engine then the term sucked valve would be more appropriate as the valve would be sucked up on each compression or power stroke and you would experience a miss on that cylinder plus a whole lot of metallic noise
If anyone else has a better way to explain this please chim in.

 

That was very well stated.

In essence something in the valve fails allowing the part of the valve in the combustion chamber to just fall on the top of the piston .

Where it pretty much makes the engine a boat anchor.

taking out the head the piston and if your luck is like mine the block as well.

Now if this is a very expensive engine things can be repaired but your normal Toyota engine you could buy several for the repair cost:jessica:

 

Thanks I believe this is similar to what I found on the net.

usage: I see your jeep is broken down on the trail... what happened suck a valve?

I believe I saw the term used here and ttora... usually when making fun of Jeep's... wasn't sure what it meant.

thanks

 

Another possible term. When I had my 85 I hydro locked my 85 a few months later I had a damaged valve get sucked down in to the chamber and jammed the piston the rest is history. Quite a few mechanics I talked to said "awww you sucked a valve"
Just one more option.

On a funny note my lady called my neighbors pathfinder a imitation 4 runner. Thought that was awesome.

 

yeah... after pulling off my head and getting a good look at the working mechanics of it all...

yes... it's when damaged valve falls or gets 'sucked' down into the chamber and then crunch...

 

Wow my bad lim50 & Wyoming9 both got it. I guess I was too eager to reply that I didn't read all the posts.
Side note
It sucks when it happens to you but at the same time kinda awesome to witness