1999 Buick Regal 1999 Regal LS

I'm assuming the engine's cranking but not firing? When you crank it, does it sound like it is trying to fire at all, as in does it sputter, spit, whatever you want to call it?

As far as how that much oil is getting in, well, it's hard to say. Oil is not, exactly, a rare thing in a motor (like coolant, which only has a few select paths into the combustion chamber).

Valve guide seals, rings, head, block, etc. Basically, the chamber's surrounded by oil. At this point, my main question for you is. "How much is the car worth to you?" Any decent mechanic, or even mechanically-inclined individual, with enough parts/supplies, tools, time (or money) can get the job done. The valve cover gasket, I would have to say, is not what I would say the cause is, it's a cheap fix, yes. I am, I'll admit, more familiar with the V8's, but I have yet to work on a car where the valve cover gasket would actually prevent oil from getting into the combustion chamber, at least in that kind of quantity. Head cracked, shot rings, maybe a REALLY bad/non-existant valve guide seal, but I don't think it'd be the valve cover gasket.

Did this happen suddenly? Has the car been blowing smoke for a while (out the exhaust)?

Keep in mind, once oil gets into the cylinder (in a large enough quantity to do what you're describing) we're talking about other damage as well (granted, not horribly expensive, but damage nonetheless). Catalytic converter, O2 sensors, wouldn't surprise me if the EGR will need cleaning, etc. Etc. Yes, you can try replacing the valve cover gasket, o2, cat, clean the egr, and run seafoam through that motor and hope it cleans 'er up, but still.

Not saying "sell it", but that this might be as good of a time as any to "get out while you're ahead". Others might say try the valve cover gasket, but I'd bet it's coming from somewhere else (and as far as the oil getting into the chamber through the ValveCoverGasket, if I'm wrong about that, correct me; not pretending like I know this engine design at all - more of an OHV guy myself - but just saying iirc it's not likely).

Ok I just got it checkout a mechanic put the valve cover gasket on its 2 prevent the oil spillin out. While he was looking at it he open up the engine a little and notice my coolant was mix with my oil which he said that it was bad! He said could be a crack head gasket or block but dosen't know because he has to take it apart to fix out! He told me that I can get a head gasket put on. But he also said that there a formula for when this happen. He said there's a seal for when water mix with oil and he said thats theres a 94% chance itll work on the net, he told me to flush the engine oil, coolant and radiator. I just want to know have you heard of this working? I feel what you are saying as well im basically trying get it up n running so I can sell it! Im just tire of going through these problem a pain the but.

They do make formulas, but they make a mess of the engine as far as rebuilding, since you have to then get that gunk out of there.

Either way, it's up to you. You can sell it "as is" as a mechanics special, might find someone willing to put in the time and effort (as well as money) to rebuild that engine. You can sell it to a junkyard. You can sell it as a parts car, and find someone looking for parts for that car. Part it out yourself. Junkyard it. Use the formula and then sell it. Or even rebuild it (shell out the extra money) and then document the rebuild and sell it as a "like-new" car with a fully refreshed engine.

Not going to tell you which option to take, it's honestly all up to you, and each has it's ups and downs. But, those are the various options I see for it. If you rebuild it, it will definitely sell for a WHOLE lot more money, as it's effectively a "zero miles" engine, but whether that will offset the cost of repairs or not I cannot say or even guess at. The others, once again, I'm not going to try and speculate as to the auto market in your area, or for that particular car. I will tell you, though, if the formula doesn't work, it is very likely it'll make it a complete mess to try and rebuild.

Also, since it's mixed oil and coolant, that's another mess altogether. It makes a nasty sludge, and will clog up lines, passageways w/i the motor itself, and can, quite possibly, do further damage.