I picked up an 04 LS Sport 5 speed with 70k on it. I changed the oil about 3 weeks ago or about 1000 miles ago. I filled it up with Mobil One synthetic. I checked the oil today and found that the stick was dry. I picked up 2 quarts of oil at autozone along with a can of restore engine/oil treatment and that brought the level back to where it needs to be. The previous owner replaced the muffler but never put a tip on it. The exhaust exits right out of the muffler under the car about 20 inches before the bumper. After looking under the car the area surrounding the exhaust exit is covered in black soot. I have never noticed smoke of any kind coming from the exhaust. The car makes a little bit of top end noise on excelleration through 1, 2 and 3rd gear but quickly goes away after one or two normal pulls. The car only has 70k on it and I cannot believe it is burning through 2 quarts of synthetic oil in 1000 miles. I even used 10w30 when I changed the oil in hopes it would quiet the motor down. I ran half a can of seafoam in the oil for about 100 miles before I changed it, seafoamed the intake and changed the plugs and filter when I changed the oil. The plugs I pulled out looked fine. Nice tan tips with no oil on them. What could possibly be the issue?

Maybe its blow by from clogged PCV issue. There is a hole in the intake manifold in the center for the flange and the clog. It you take the intake manifold out and clean the hole out your issue may be resolved. I had this same issue after a ecotec swap.




On the inside my car looks like a fighter jet.

Not that this thought is incorrect but here it is.If the original owner used just conventional oil versus synthetic over that mileage it can be the engine is just burning it off.I have learned switching blends conventional to synthetic some (not all) engines can be particular to a brand,version of oil and will just use it with no leaks or real problems.I have not ever had this issue but,do know at least on the diesel side(big trucks) where this has had happen it was changing oil brands or versions and like the issue you have had.I might suggest checking with the original owner to find out what he used or had put in the car as a comparison at least to know.Crazy sounding but I have found this to be true to a degree on some brands on some rides I service using different brands.Just a thought unless something else is going on mechanically.Keep in mind conventional versus synthetic is def different on how it works from a certain point.

I think I can rule out the oil brand and conventional/synthetic idea. The guy told me he had the oil changed 3 to 4 weeks before I bought it. A couple days before I changed the oil I checked the oil when I added the seafoam. It was down about 2 quarts then too so Id venture to say its burning oil regardless of brand or blend. I did the old paper test a little bit ago. Held a piece of paper at the exhaust exit and had my girlfriend give it a little free rev. She refused to follow directions and rev it passed 2500 or so, but even so the paper showed quite a few dots of oil. I guess its more or less blowing oil rather than burning it. Ill have to look into the PCV theory. Ill tear it down tomorrow and clean the intake manifold and PCV system. With the amount of oil blown all over under the car its really making me wonder what the inside of the cat looks like and the o2 sensors. The car isn't throwing a CEL so hopefully all is good with those parts. The car runs good, idles smooth and gets great fuel mileage. After a bottle of techron injector cleaner I went from 30 to almost 35 mpg. This is the first ecotec engine I have ever owned and it doesn't really feel much faster than my girlfriends old 2.2 cavalier. Hopefully once I get this oil issue figured out that will change. I know it isn't going to be a killer on the street but I was expecting a little more out of it than this. I was planning to go cammed and boosted this summer but that's on hold until these issues are resolved. No sense boosting a junk motor.

Check the vacuum line going to the fuel pressure regulator smell it if it smells like gas the far is bad. Gas In the oil is bad. Other than that piston soak but it might need a re ringing


see ya!

I was able to tear into the car today. I got the intake tubing all off and found it to be coated in oil. Old oil, really nasty sticky oil. I pulled the throttle body out, it too was covered in that nasty stuff. I was going to pull the intake manifold off but decided I didn't want to go that far into it since its not exactly warm out yet. After taking the throttle body off I looked down into the intake manifold and the bottom had a pool of oil in it. While I had the injectors out I soaked them in seafoam and sprayed the crap out of the injector ports, throttle body, intake tubes and inside of the intake manifold with carb cleaner. I made a small hose for my shop vac so I was able suck up all the broken down oil and scum. Cleaned out the PCV valve and line along with the vacuum line from the valve cover to the intake. After putting everything back together the car isn't blowing oil and the throttle response is way better than it was. It definitely has a little more pep now but it falls on its face at about 4K, as I run it up to redline it has slight "pulses" of power passed 4K. It seems to pull a little harder for brief seconds as it gets to redline. From idle to 4K the pull is strong and consistent, afterwards its iffy almost like its getting fuel cut off. When I was tuning my boosted GTO I hit fuel cut off a couple times and it was like hitting a brick wall but this isn't that severe. I have run a couple bottles of techron through a couple full tanks as well as soaked the injectors so I cant figure it out.

This maybe a stupid question but did you use a new gasket or o-rings for injectors might be pulling air in from somewhere.

All 4 o rings looked perfect, same with the throttle body o ring style gasket. The surging power seems to be slowly going away. Now its making it up to almost 5k before it dies so hopefully it continues to improve.

You figure out your problem? I have the same issue and can't figure it out either. So annoying filling it up with oil all the time and never seeing a drop on the ground nor seeing smoke like it's burning it off.

do a compression check its very possible that your rings are carboned up. try some lucas fuel treatment