jovansmunoz

Hi, so I just recently bought this GC has 260k miles. I've noticed blue smoke coming out the exhaust when accelerating, idle and at start up. Its not excessive smoke but it is noticeable. Also i noticed smoke coming out the right side of the engine, i think its the exhaust manifold. Also it seems to be burning oil, i put at least 1qt every week. There's no leaks. Could it be bad valve seals? Or can it be the rings? Some people say it could be burning coolant but it hasn't gone down its always at the same level

dave1123

Blue smoke is always a sign of oil burning in the cylinders. I'd suggest a complete compression test to start with. Check the CCV system for oil from blowby by disconnecting the hoses and watching for oil vapors coming out when it's running. Also look for a cracked exhaust manifold. Bad valve seals will show up as lots of smoke when decelerating down a hill in a lower gear when vacuum level is high and on startup. This could be caused by oil pooling in the heads and not draining back fast enough.

I would think it's rings because it's noticeable on acceleration. A 4.7 is not an engine that can be hammered on and because of the mileage is probably worn out by now.

jovansmunoz

Ok i will do that first thing morning, as for now i bought this ring seal additive, it seemed to have stopped the smoke, its night so i can't really tell. Will work and what you recommended in the morning and ill update once im done. Thanks!

blueseasons

Black smoke fuel. Blue smoke oil. No smoke good.