Thread: Are my pistons screwed?

affirmative

The only mods that I had on the engine was a Thraser CAI. Now there was an instance that caused me to think that there was piston damage. My car started misfiring and I pulled the spark plugs and the plug on the third cylinder was damaged. The ground electrode hit the center electrode tip and I guess I should have looked into it further. Oh well, I guess that's it, new block time.

The car I purchased was a one owner car. Was owned locally by the town dentists wife.....old couple. It had 100K miles on it and was traded in for a caddy STS. the car was BONE stock and maintained at the local dealership(they have a good reputation there) I doubt they caused the damage, as the car ran great for 4-5 months after we bought it. Oil was never ran low,coolant was topped off. It started running like crap well before it got cold out.

I will say this the coolant was breaking down,I'm assuming it was the original dexcool crap. There was alot of mud in the engine block passageways, upon tear down. I know that didn't help with heat dissapation but the car never ran hot. It was getting 30+mpg on the highway when she went on trips and high 20's the rest of the time. That too me was a good indication of how easy she was driving it and how good of shape the motor was in initially.

she said it just started running rough one day and the fuel mileage dropped off like a rock. I swapped cars with her and started going through it. Thats when i found smashed plugs,i wasn't immediately aware of the situation so I put in new ones and drived it for a few more weeks. It was ok but the mileage still sucked, I figured the motor was failing. Well long story short we got in a huge argument she took the car back and drove it as is. It died on the freeway and was towed to her place and eventually back to my garage.

So either it did get a tank of 87 and detonate itself to death and the resulting heat made the pistons chip out. Or it just failed from multitude of things,crappy coolant,possible 87 octane fill and high mileage. regardless I just want to get the motor back together and not have to worry about this happening again. because if others have had it happen when running 93 on a stock motor, who says it won't happen again?