Hi, early in marsh I took my wife's 2018 Mirage (55000km) to the dealership because of an engine noise that would not go away after the engine had warmed up. They charged me 400$ to do a compression test and tell me that Mitsubishi would not repair it on warranty because the oil change had some time been done 2000 km to late....
After some phone call leading to dead-end, I decided to repair the engine myself as the dealership would charge 3000+$ and I estimated the repair to 400$
Now the engine is out of the car and opened up. The 3 piston have damage to the skirt on one side and the wrist pin are not turning freely in the piston. The cylinder wall have the same kind of damage as the piston.
I would not find any oversized piston for the 3a92 so I ordered a piston set from rockauto for a toyota 1nz. Same bore, same pin, similar valve relief, the compression distance is a little longer. That I will adjust when the block come back from the machinist.
The crankshaft look like new, all the bearing have minimal to no wear at all.
The machinist said that by the look off the piston, the damage would be due to overheating or to excess gasoline.
The engine would flood 3-4 time during the winter and we would have to start it with full throttle. It would smoke black and smell like snowmobile and then run fine. We have never experience overheating with the car.
Maybe the engine would run lean and overheat the piston after the over-fueling event like the 2014-2015 were doing...
I will post picture of everything soon, do you guys have pics request or dimension you would like to have before I put it back together?
Sorry for my English, I live in Quebec, Canada and do not type in English normally.