burning oil

is it common for a 1991 ls with a b18 to have oil burning problems as far as i know the car is stock engine wise so any guesses on what i should check first. if it helps at all the car is burning at significantly random rates sometimes really fast sometimes really slow.

The two most common ways in which oil gets into the combustion chamber on our cars is through the valve stem seals (which shows up as a big puff of smoke when starting the car as oil runs down the valves and into the combustion chamber or the back side of the valves) and the second way is by slipping by the rings of your pistons during operation. I suspect you are probably leaking oil as well. The different rates most likely has to do with driving style and time vs. mileage rate changes.

all i know is when i start it theres alot of smoke from it and apparently when i shift it gives off another big puff. if it is leaking it cant be much because i would of noticed spots and there are none.

sounds like valve stem seals

Yes it is a common thing in higher-mileage cars, it occurs simply due to old age. A leak-down test would tell you if the oil is passing by your rings or coming out of the valves/seals.

alright thanks guys

yup also check your vacume lines and breather chamber for any leaks. You want to have the pcv valve replaced and make sure you connect the hose on the valve cover to the intake like it should. it helps the crank case vacume in your engine.
What exhaust do you have cuz I have a stock catback and I dont see smoke, even with a hollowed cat and 4-2-1 dc headers on a vtec b18c…

if you have a bigger pipping and a cannon exhaust tip then its normal, even more when you have an old cat.
two things you should look into is first make sure your oil level is going down if you think your burning oil. what you say you see could just be normal smog.
top off your oil then check it 8 days later and if its at the same level or very close then your good, i assume you redline it offten since you see alote of smoke all the time…
all engines burn oil when they rev at high prms, some burn a lil while other burn more…

no iv only redlined it twice but it does have an aftermarket exhaust but is burning from the sheer fact the exhaust fumes smell insanely like oil and i have had to put more oil in about ever week and a half.

yeah most likely need new piston rings or new valve stem seals, maybe even new valves. You pretty much need a rebuild or new engine, only thing I could think of to reduce the oil burning smog is adding a heavyer/ thicker oil weight.

what kind of oil are you running? switching to high mileage oil will help ur problem especially if ur running synthetic