What did this to my cylinder walls?

[AKcharger]

Ok, disclaimer, this is a Toyota 4 cyl engine but thought I'd ask here. Background story; my sons truck, 6 months ago we had the head off for a timing chain and cylinders were pristine, I was amazed with 200k... Not even a ridge! Anyway, he severely over heated it a few times and it was running very bad. I figured at least a head gasket, at worse warped head.  If you look at #2 there is circular damage to the bore, I'd guess about .035 deep running about 60% of the cylinder. #3 looks to have a crack in the bore, goes all the way around but can't catch finger nail on it.

Of course the eng is done but what exactly caused this? Did the rings melt or something?

[Kern Dog]

Maybe water sitting in the bore during a high heat situation?

[68CoronetRT]

My Guess is it blew the 2-3 cylinder area and water was able to get past the head gasket under high pressure and sit there before the next start up/run. That caused the rust/problems. I also bet that your rings are broken because of this.

I've built 3 22re's now and every time they blow in between #2-3. But I also push the motor with a turbo setup and ARP studs etc.... If you have any questions about the rebuild feel free to PM me.

[Cooter]

Lack of cooling system maintenance.  Coolant that looks like river mud will turn to an acid base. Once allowed to sit next to bare metal, it eats everything.

[AKcharger]

Thanks for the input guys. I'm with ya on water in the cylinder but that doesn't explain the deep grooves cut into the cylinder walls. Is it possible for the rings to get so hot they could temporally "weld" themselves to the cylinder walls?

[68CoronetRT]

My guess is that due to the excess pressure from the water/coolant in there, that the rings broke and are what is causing the deep grooves.

Same thing happened to my little bros 84 pickup, and it broke the rings from the blown head gasket)or maybe they were already broken?). Luckily it blew so bad that it dumped the entire coolant at an intersection and he shut it down pretty quick saving the cylinder walls.

[AKcharger]

Ah! Gotcha!

[fy469rtse]

Sorry to tell you but gauges need to register of fluid for temp gauge , what ever went wrong , gauge didi not register until block temp made sender register to gauge, not off the fluid but the engines temp , excessive temps did that damage , temp gauge is probably the most important to watch, I had an engine once that was running oddly cold then as driving along gauge started to gradually climb and kept climbing to hard over, by the time I realised what was happening it was too late , block temp made sender register to gauge, excessive heat ruined motor