Engine Performance problem
2002 Chevy Express V8 Automatic 130000 miles
Hello. I have a Chevy Express 15 passenger van with 130,000 miles. When I first start driving it, everything is okay and the oil PSI is about 40-60 PSI. Once I've driven for about 5 minutes and come to a stop, the oil pressure drops less than 20 PSI. After idling for a couple of minutes when the engine is hot, it drops to less than 10 PSI, the check gauges light comes on and the engine cuts off unless I press the gas. Also, when backing up, sometimes the engine cuts off, but it starts right back up. We've had the oil pump replaced and have also put a higher grade oil, just in case, but the problem is still there. What could it be?
Sometimes this can be an oil filter that causes the problem. I only reccomend 3 different types. AC/PUROLATOR/ WIX those seem to be the most reliable. Then get a mechanical gauge and see if you get the same thing. If you do you could have a main/rod bearing problem but I don't think so. Don't waste your money on chemical treatments as they don't work. You could also have a bad oil pressure switch as that would cause the engine shutting down.