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Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
23,849 Posts
What engine oil are you using? I have seen some high-mileage Mitsubishi 2.5L V6 engines with oil burning/smoking issues. I have a '98 JX with the 2.5L and 122K miles that smokes at odd times. Sometimes it's at start up, especially after it's after sitting awhile and sometimes it's when it is hot and climbing hills.
It's the infamous Mitsubishi valve seals from the '80's -'90's. The rubber has worn and hardened with heat.
Replacement can be done with the heads on the car, but would be about a days work in the driveway with the right tools. There are 24 valves and the rockers have to come out of the way, cylinder pressurized with air one at a time and valve springs R&Red.
If the cat is hollowed out at all, the oil smoke will be worse as the cat helps to oxidize some of it.
Going to a slightly heavier viscosity of motor oil can also help reduce smoking. In warmer climates, a premium quality grade of 10W-40 may help reduce smoking. 20W-50 may be excessively thick. HDEO is more expensive, but may also help.
Maybe with the A/C on, you are adding load to the engine and seeing the smoke. I would bet that if you were to follow your own car in a car behind it, you would see wisps of oil smoke at other times like when the engine is under throttle and the throttle is let off when warm, etc.
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