What caused this valve cylinder hole? This is number 1 on driver side. Hiw did it even run well because it was running prettt decent(b4 blew head )

[cwbysmith]

 

[donalds]

Pre ignition detonation

 

[cwbysmith]

Pre ignition detonation

Pre ignition detonation makes sense. Im a newbie so just curious what causes that. Obviously I will be ordering a new cylinder head, want to make sure it doesn't happen again

 

[Turdle]

Pics of all combustion chambers please

 

[cwbysmith]

Pics of all combustion chambers please

I can only show drivers side because of timing chain in back on passenger side i have to remove engine to access block. This 05 explorer. This is other 2 .

 

[cwbysmith]

I can only show drivers side because of timing chain in back on passenger side i have to remove engine to access block. This 05 explorer. This is other 2 .

 

[Turdle]

Chamber on far right has hole also.

Intake leak , hot combustion my guess.

 

[FordFlintrock]

If you look at the first pic the center electrode of the plug has burned away leaving a .250 gap? The engine cooling system looks like it was running with straight water.

 

[Turdle]

If you look at the first pic the center electrode of the plug has burned away leaving a .250 gap? The engine cooling system looks like it was running with straight water.

Kinda looks now to me maybe coolant freeze, then cracked. Looks cracked not burned . Icky.

 

[cwbysmith]

Chamber on far right has hole also.

Intake leak , hot combustion my guess.

Here's close up after cleaned up a little, looks like small hole was pieceof metal/dirt...instill see one piece material

in this pic. There's similar damage in same place on all 3 for sure so I think issue was all 3... this my first time breaking down engine so im not arguing just hoping to add info. I've looked close and i dont see a hole yet in one on other side. Research said carbon buildup, bad spark plug could cause this but plugs look ok

 

[Josh P]

Kinda looks now to me maybe coolant freeze, then cracked. Looks cracked not burned . Icky.

I am thinking the same.

 

[cwbysmith]

Can you explain coolant freeze. Tried to Google it and they just refer to temperature. Pretty sure I'm going to just buy a new head so as long as it won't repeat with new one I'll be happy but would like to understand

 

[Turdle]

When water freezes, it expands with force. Metal breaks at weakest point. Looks like no anti freeze in coolant, which allowed it to freeze solid.

 

[Josh P]

The hole looks similar to drilling a block wall.

 

[cwbysmith]

When water freezes, it expands with force. Metal breaks at weakest point. Looks like no anti freeze in coolant, which allowed it to freeze solid.

It happened in summer but i suppose its been through many winters. Would that be a valve or gasket issue because coolant shouldnt be in combustionchamber ?