my 04 trailblazor oil pressure drops to 0 when when idleing is that bad

Yeah, the oil pressure on my 93 Pontiac Bonneville has been acting up when I first start it. It usually runs rough at first and the check oil level light comes on and the oil pressure gauge goes back a forth a bit. Oil level seems to be fine, though.

How old is the oil? Is it at the full mark on the dip stick? If the oil is old or low that could be your problem. Start there. If not that, could be your oil pump. That's not good. Hopefully it's one of the first two.

Have a secondary oil gauge placed on it to eliminate the pressure gauge is bad. If it is good, assuming you've checked the oil level, have your oil system flushed out. It may be a clogged screen or junk at the sensor pick-up. You then may have the oil pump checked, which will be costly, and if you tear into it, it may be a better off thing to put in a rebuilt or new pump at this time. A good mechanic should be able to do a quick check on your rod bearings. How many miles do you have on your 2004 Blazor? Has it been taken proper care of? Has it been exposed to road dust or dirt and rode hard and put away wet? Meaning frequent oil and filter changes if exposed to above normal dirt exposure? It may be than worn bearings and a needed overhaul. Go to a trusted garage for assistance if your not a motor head.

Most likely its the dash gauge stepper motor. When they fail, the gauges act react erratically. I have an '03 EXT with a 5.3l and three of the gauges are acting up. The repair is to send the dash panel out for motor replacement or obtain a replacement panel. http://ezinearticles.com/?Trailblazer-Instrument-Cluster-Repair---1-Odd-Reason-They-Fail-and-the-4-Choices-for-Repair&id=5257758

Man oh man, bring back the older cars with simple replacements.

LOL I here ya. Thats why I building a 69 c10 for me and a 65 pony for my wife. I'll post pics as I go. Good luck with your Blazer.