Oil light flashing occasionally

This is a good time to check ALL underhood levels...oil, water, etc. Also, check your gas cap...turn clockwise to hear 3 clicks...you may have to drive awhile before the Check light goes back out. Hope this helps.

You did not say how cold it is but I am guessing that the viscosity is not correct for the temperature and the oil is too heavy for the job.. May be an oil change to the correct viscosity oil would help.

could be a loose or dirty connection on oil sensor

The way to reset the oil light on your Trailblazer is.You first turn the key on but do not start the vehicle.Press the gas pedal 3 times all the way to the floor within 5 seconds.The change oil light will flash several time then go out.The oil life has been reset.Remember don`t start the vehicle just key on engine off.Hope this helps.Good luck.

When the engine is running at idol the oil pressure drops causing the oil light to flash or come on. While driving the engine is running harder and oil pressure is increased and the light goes off. Your oil level may be low in the engine or the oil pump is starting to fail. Is this a vehicle with high mileage?

You can fiddle with thiis and check oil pressures but best is sump off, thorough clean, teardown the pump thoroughly clean it and pickup and replace it if any wear or the pressure releif spring is weak.You have given no mileage and no information on the oil used nor whether in a really hot area or 'where'?..there are several considerations ranging even into worn bearings...Of course with acceleration motor speed increases oil pressure...that's why light goes out (unlikely but possible the sender unit is faulty...but try replacement of that first if you want...) It doesn't take a lot of pump wear to cavitiate and drop oil pressures.

check for proper oil level in engine with dipstick if ok.then install mechanical oil pressure gauge on oil pressure sending unit to verify proper oil pressure, if pressure ok. then replace the sending unit/sensor, if pressure not ok. , you may need to remove engine oil pan to check for restriction on oil pick-up tube screen. if ok replace pump. but also check clearance on mains and connecting rods.

the oil level may be good and quality may be good, but the oil pump may be going out considering the valve/engine noises. Have it checked quickly, before this engine locks up.

If the engine is not making any ticking noises while light is on, it's likely that the oil pressure sending unit is going bad. Generally, it's located near the oil filter, but every time I tell someone a location, I'm wrong. (can't remember everything) It's not hard to find and anyone at a decent parts house can point it out to you.
good luck also check that the wire going to it is not chafed and shorting to block!

Sounds like possiblity of the oil pump being bad, and is setting off other sensors on your car.