when i stop at a light my oil pressure goes to 0 until i hit the gas and its normal again 02 trailblazer

A couple of things come to mind. When was the last time you changed the oil or the oil pressure sensor is defective. Dose the engine knock or rattle when the oil pressure gage comes on? If so you might need to replace the oil pump. Lots of variables.

Check the oil level. park the vehicle on a flat surface and turn it off. Wait for 5 minutes for all the oil to drain down into the crank case. Pull out the oil dip stick and with a paper towel or clean rag, wipe it clean. Reinsert the dip stick and pull it out slowly. Look at the oil, if there is any, that is on the dip stick. That should tell you if there is enough oil in the crank case. If it is full or even one quart down, the sensor may be going bad. Worse case is your engine is ready to toss a rod.

Have someone check to see if the gauge needle motors are bad. This was a huge issue with earlier models. You can either change the whole cluster or have the motors changed. There's a guy on EBay that is an electrical Engineer and Factory trained for repairing these clusters. I believe he gives free estimates but check to see. I have a later model now and don't have that issue anymore. Good luck

Is the oil cap on all the way. That can mess with the pressure

My 02 trailblazer can be running just find until I stop for a red light than my CHECK GAGES LIGHT COMES on truck starts run rough if I make a certain turn it cut off but starts right back up it does find as long as I am give it gas can u tell me what I need to do

Stanley my man. Who stops for red lights? Problem fixed! This sounds like you may have some blockage in the fuel lines going to the injectors or the injectors themselves are in need of some TLC. There are additives that you can put into the gas tank on a full fill up that will help resolve some of the fuel build up. I always use mainly two, or on occasion, three blends of gas to keep the build up from happening. Top brands usually have their won cleaners in the blend and by using more than one, you get different ones. When I go on long trips, I add the fuel cleaner in the tank and half way through the trip, I again add a bottle of the cleaner. Try it. It is far cheaper that a traffic ticket for running a red light. You can find it in some gas stations or car parts places. Worse case would be having a garage clean out the system. This is usually two big bills. Also change out your gas filters. Sometimes water may find it's way into the system and cause some problems. If you change the filters, look at them to see if they have contamination or gunk that may slow down the flow of gas. Cars are like wives. Look good, run nice only if you spend some money on them. both have great rewords. Take both out for a spin when you get it fixed. Best feeling in the world my friend.

This is happening now to my 02 gmc envoy. Exactly as he describes. I'm supposed to leave for a 1600 mile road trip in the morning. Am I good to go and just have it looked at when I get back? I just had the oil changed, so it can't be that.

Did you ever figure out the problem and fix it? Mine is doing tree same thing now

I had this exact issue off and on with my 2002 Envoy for a few years. I had to take it to the dealer for some recalls and the service advisor me mentioned that the I6 engines are very picky about oil filters and my local shop was putting Fram oil filters on. I started using only ACDelco oil filters and have not the problem since. It's cheap enough to try to see if it resolves your issue.

I have the same problem in my 2002 trailblazer i check all over my 4.2 engine and found the throttle not clean i cleaned carefully and now the oil pressure is normal

GM uses the oil pressure sensor voltage to the PCM to ground the fuel pump relay. No oil pressure-no fuel pressure.

You need to start using synthetic oil and make sure you do it yourself because you can't trust none of these mechanics out there to put the rice s*** in there it definitely needs a oil change that's what that means or your oil levels are low which usually means is burning oil and if it's burning oil you need synthetic oil

My 2003 Trailblazer has had oil change transmission change the fuel filters and had transmission work done the sensors in the transmission they said and still I'm having trouble with the sensor lights coming on about the oil my oil gauge don't show that it drops it stays the same even it goes high or Toda 40-point done clean fuel injections changed one out put some cleaning fluid and the gas stale check gauge light comes on all pressure gauge comes on and stop engine light comes on had a po440 to show up on the monitor they stuck on it still can't get it to quit with the oil I the po440 says that they are some kind of vacuum is happening to it and done checked cat gas cap put a new one on so I don't know what it is

Has anyone found a solution to this? For the love of God!!!

I just changed the oil pickup tube o ring problem solved. It requires removing oil pan.

Our 2002 is doing this EXACT same thing. Oil is full. Looking for the solution like everyone else.

Having same issue and i recently had the oil changed and also put new synthetic oil in it. So it’s not that I need an oil change. When my 2003 trailblazer is in park the gauge goes to 0 and it says to stop engine. When I drive the gauge goes to 40. Anyone know why????

Check your gauge cluster might be going out or the oil pressure sensor, but worse case senario is the oil pump itself is about to take a crap, with higher rpm's the oil pressure raises then at idle goes to nothing means the pump. If irratic movement all the time the gauges or oil pressure sensor is going out.

I have a 2006 trail blazer when i crank it oil gauge is right after i drive ir 10 or15 miles it drops to zero.Had oil sensor changed didnt fix it.motor does not knock or rattle .