我不知你看了我的回帖没有，造成你目前情况的大致有三种可能：
最乐观：PCV堵塞或油垢太多需清洗或更换，很便宜，5-10刀的零件，再就是勤换点机油。
中度不幸：Valve stem seals 需要更换，这个可能要300-500+的手工（看几个缸看车），零件20-30刀。
最不幸：发动机要开膛破肚，换活塞密封吧，价钱要车铺quote吧
如果只是准备再开个1年半年那就算了，依旧依旧吧！就是起车的时候尴尬点儿。
如果想修首先要确诊到底是那个的问题，这个你要去车铺要询价。
我感觉之所以发生烧机油故障，和日常保养有很大关系，当然有些原厂零件的使用寿命也会有关，但如果是小概率发生事件，保养的好至少可推迟/延迟这类问题的发生，特别是2手三手的车，你很难知道前几任车主的保养情况，所以可能发生故障的风险就更大。
文摘转录（仅代表作者的观点，不是标准答案的问题）：
Since it's blue smoke you are seeing, you can know that oil is the problem. What can cause oil smoke?
If the smoke only comes at start-up and quickly goes away, it can be valve seals and/or valve guides. This is because while the car sits for extended periods of time, the oil has time to seep past the valve seal and collect on top of the valve (or if the valve is in the open position, it could run past and on top of the piston). When you go to start your car, the oil is then burned, giving the tell tale puff of blue smoke. COST TO FIX: There is moderate cost involved with this, depending on the vehicle/engine. If just the seals, this can be accomplished most of the time with keeping the engine mostly together and replacing the seals. Most of the cost here is labor. If the valve guides, this requires an engine tear down. Your heads will have to be taken apart and new guides installed. There is a lot more labor here and a bit more in parts.
If you see smoke as you are decelerating, this too is a possible sign of valve seals and/or valve guides. This is because as you decelerate, there is a large vacuum build up within the intake tract. There is enough vacuum to pull oil past the valve seal if it's worn. COST TO FIX: Same as above.
If you see smoke while accelerating, this is a sign your oil control rings are worn. These are the bottom rings used in the ring pack. When they are worn (or the cylinders are worn past tolerance), oil can flow past the rings as the piston travels down the cylinder. The oil control rings normally will scrape the cylinder of the oil, pushing it back down into the crank case. COST TO FIX: There fix is quite expensive, as it requires a complete engine rebuild to fix.
If a PCV is bad, you normally won't see burning oil. What you'll see is seals and gaskets failing. This can cause a loss of oil (and a very dirty engine bay). It's one of those things which can sneak up on you if you aren't paying attention. While a bad PCV is not a good thing, don't look here for a reason you're seeing oil smoke coming out the tail pipe. COST TO FIX: If you catch it before it becomes an issue, it's actually quite cheap to fix ... just replace the valve. If you see leaks at seals or gaskets, your expense goes way up, but it depends on which seal or gasket is leaking. Easy to get to seals or gaskets will cost much less, because the labor is much less. The converse holds true - Labor is a determining factor here.
If you are seeing blue smoke which goes away after an oil change, but slowly comes back as you get closer to your scheduled maintenance, this could be a sign you have an internal fuel leak which is thinning the oil. As the oil gets thinner it passes by the oil control rings easier, causing your vehicle to smoke. An easy way to check this is by pulling the dipstick and smelling the oil. If you smell fuel, this may be the issue. This can be caused by an injector which is stuck open, or possibly an internal failure of a fuel pressure valve which would allow the gas to escape to where it doesn't belong. COST TO FIX: Diagnosis of what is going on will take a little bit of money. This could be a very low cost fix, to a moderate cost, depending on the actual cause.
If you are not seeing smoke, but you're seeing the oil drop lower and lower as time moves on, this may be a "sort of" normal oil usage in your vehicle. Take for instance my '06 Chevrolet Silverado. Its engine is an LS variant. As these engines get up in age, it is common for them to use more oil. You don't see it from the exhaust, but it uses it up, none the less. The engine still runs great and the gas mileage has stayed about the same.
Your vehicle could also be losing oil via leakage (or seepage). As engines get up in mileage, this is a very common thing. If you see spots on the driveway where you park the car, this could very well be the issue. Be mindful that vehicles will loose more oil during operation than they will just sitting in your driveway.
EDIT: In deference to your edit - I can see where an up-to-temperature catalytic convertor might make some difference in smoke from the tail pipe. This does not hold true, though, for start-up smoke (puff of blue smoke), as the cat is not hot enough to make a difference. It also won't make any difference once the catalyst is covered in oil suit or if there is too much oil for the cat to deal with. Sooner or later when oil gets burnt in this manner, you'll see the blue smoke. You probably have to put new cats on at that point, as well.
