I have a 2002 sc2 DOHC, when i bought the car it smoked really bad! Its not really smoking when it first starts up, wait about 2-3 minutes or when car starts to warm up then she really starts puffing! Smoke is constant on idle, a bit worse when revving or driving, but even at idle i cleared out my whole neighborhood. I was already aware of this and believed i could fix it. Did a compression test and all number were good and even, I figured the oil control rings might be bad because it doesn't really smoke on start up but billows out smoke shortly after and never stops, tried the mmo soak three times before i started the car again, first time the mmo disappeared from the cylinders in about 2-4 hours, the next time it took about 10-12 hours and then the final time it took about a day or so. So i said fine, maybe i freed up the rings a little bit because i thought they might be sticking. Changed the oil, fired her up, as usual no smoke(minimal) on start up...warms up..not really smoking...i figure hey! the soak made a difference...wait a bit more, smoke starts coming out...progressively worse and before you know it its smoking just as it did before i did the soak, I did use a thicker oil to see if that would help also but that maybe why it took a bit longer to smoke.

After that I say what the hell and start tearing it down, I took off the head, there were small puddles of oil in the cylinders and oil on the surface of the block by the return holes. Headgasket was perfectly fine(a few days old), took the head to my machine guy so he can take a further look at the heads.

cylinder walls still show hone marks, not great but still visible. Took the bottom end apart, compression rings are within tolerance, rod bearings and main bearings show pitting, im guessing the previous owner didnt prime the oil pump before first start up after rebuild( He replaced rings, bearings and got a machined head and had this problem so I took it off his hands to fix it)

How can I tell if the oil control rings are bad? They weren't stuck...neither of the rings were.

As of right now I have no clue as to why the car is putting out sooooo much smoke out the exhaust. YES it is oil because after about 20-30 minutes of running the oil light comes on and there is no more oil on the dipstick!! That is alot of oil to burn in a short amount of time!!

Can anyone else give me some insight? Maybe someone else had or has this problem? I already know saturns burn oil as it is, but this is not one of those cases!

How else can oil get into the combustion chamber? check ball in PCV is fine, wiggles and i can blow into it. Rings look good to me unless im missing something, valve seals may not be great im not sure yet, but even so would it smoke THAT bad? What am i missing here?

 

I ain't believing what I'm about to say, but it sounds like the oil drainback passages are mucked up, or the valve guides/seals are completely trashed, or both. Since the guy got a rebuilt head, I'd seriously think about getting it replaced under a warranty issue

 

I was thinking the oil passages too until i was able to look down them with a flash light, but I didn't see anything unusual. I'll take a closer look tonight when I get off work! Still waiting on the results for the head, but can the valve guide/seals get that bad to where it is smoking constantly instead of the usual first start or sitting at a stop light?

The head bought new or rebuilt, he had the head that was on it rebuilt and machined and he even bought a spare head from the junk yard. He said he placed the rebuilt head on there, with the new rings and bearing and it still smoked! The oil control rings don't look as new, but the top two rings look fine, took the top ring off of the piston and placed it into the cylinder to check things and it fits pretty snug against the cylinder wall.

I'm really stumped!

The car has 148,000 miles

The way it starts has me stumped too (none to minimal smoke at start up, starts billowing dark grey/light blue smoke after about 2 minutes or so and doesn't stop, constant at idle and a bit worse when revving or driving.

Took it down the road and around the block after I did the soak, it idled ok, missed very slightly, but just smoked screened the entire neighborhood. Always started right up no problem, doesn't overheat at all, but by the time it has been running for about 15-30 minutes, a pretty good amount of oil is GONE, no its not on the floor or leaking around the engine.

Anything else I should look at?

 

Its almost as if the oil is just being dumped into the cylinders some how...my compression test were all good and even, there's no way in hell that much oil is getting passed those rings with good compression in less than 30 minutes

 

If it isn't the rings, then it has to be the valve guides and seals.

 

I'm with Rube, the only way for oil to get into the combustion chamber is through the rings, or through the valves. Did you happen to notice if the tops of your intake valves were wet with oil, (the stem side)?

 

It sounds like when they rebuilt the head they either didn't change the valve seals or they screwed them up putting it back together.
On the oil rings you check them the same way as the compression rings but remember that the oil ring has 3 pcs and you have to make sure when you put it together none of end gaps in the rings line up or it will smoke.
The only other thing I can think of is a small crack in the head or the head gasket had a little leak.

 

Would a faulty EGR valve suck oil out, guys? I'm not sure about that but for some reason, that popped into my head.

 

I'll be sure and look when I get the chance, the head is at the machine shop getting looked at

 

When I pulled the pistons out all the rings looked fine and were offset to where they didn't line up, the block is getting ready to go to the machine shop to make sure its fine