My oil pressure after the van has warmed up, goes to zero while stopping, then when i resume driving goes to normal. Idles fine no weird noises, does anyone know what it might be oil pressure switch, sensor?

 

Check your oil immediately. Make sure it isn't low, which is sounds like it will be. Your oil pressure will go up when your rpm's go up, that's normal. Pressure being at zero, at any time is not.

Deez

 

I am having a similar situation. My 97 express 3500 with the vortec 5700 shows perfectly fine oil pressure until it warms up and im coming to a stop. The gauge gets extremely low and the van will shut off. It starts right back up. The van has 305k on it but the motor only has about 90 on it. The van doesn't idle rough,start rough or anything it's perfectly fine except for this. Would trying a thicker weight oil maybe band-aid the problem? im running 5w-30 now,would 15w40 be to thick?

 

i have a 2005 express 3500 6.0 engine and at 317,000 miles, the lifters are noisy below 50 mph. runs well at 50 mph or over. am saving to buy a surplus engine or refurbished gm engine. did my oil change every 3500 miles at chevy dealers across southern california. body is a cut-away (14-foot box) - makes it easy to load and unload standing upright (unlike cargo van body where you are crouching). gvw is 6500 but suspensions set to carry 6000 lbs. although i often load 6500 to 7000 lbs of new car tires for delivery to car dealers. never had a problema going thru the weighing scale chp checkpoints. will look for band-aid solution to this noisy lifter problem.