Hi guys, I bought an 01 Montero Ltd. with 137,000 miles awhile back, after the last owner overheated the motor. A fairly typical project vehicle, the motor still ran, though it ran rough with little power. There was no water in the oil, or vice-versa, and I’d hoped it didn’t cook that badly. Upon disassembly, there is aluminum buildup on two cylinders, the worst of which is shown here.





I've done several head gasket changes over the years as a hobbyist, and I'm not likely going to attempt to reuse these pistons/rings. But for whatever reason, I hadn’t run across vehicles getting so hot that they start depositing aluminum on the cylinder walls. It is certainly possible to carefully remove the aluminum buildup with muriatic acid and roll the dice to see if rings are broken and/or ring grooves are sloppy. But I was wondering if any experts here know if it is fairly certain I'd have a “smoker” engine if I don’t do a full rebuild. Thanks!