Oil Pressure-Damage?

The gas gauge on just about every GMT400 truck isn't quite right it seems. I thought my oil pressure gauge was doing the same. It would randomly drop very low and then the Check Gauges light would go on. I drove with the Oil Pressure gauge occasionally going low (around 0) every few minutes for no more than 5-10 seconds at a time. At the time I did not know that oil pressure would drop if low on oil. When I checked the engine it was 1 quart low. I drove around 300 miles this way, including a 150 mile consecutive drive. How much damage did I do to my Vortec engine?

It depends on whether or not the gauge is accurate. If it is, you could have done a number on the bearings, depending on the load they were under at the time and how good the oil was that you were using. If the pressure is fine with the oil at the proper mark, then you should be OK. You can pull the oil filter and cut it open and examine the filter media for bearing material, if you want a more definitive answer. Once you have the can off, cut a section of the media out, perhaps 6 or 7 pleats. Then, with the media folded up accordion style, squeeze as much oil out of the media as you can. A vice works best, but two flat pieces of metal with a good bit of weight on them will work too. Once you have the oil squeezed out, carefully unfold the media and see if there are any metallic particle or flakes on the material. If not, you should be fine. If there are a lot of "sparklies", then you have damaged the engine. Only repair is bearing replacement and machining.

Sent from my XT1585 using Tapatalk

That oil pressure gauge may or may not be accurate, BUT, if you see the gauge reading low or zero, you shut your engine down RIGHT NOW! Then, you check first the oil level, then the gauge. If still no pressure, tow it home.

The engine lubrication system is the lifeline of the entire engine. If the pump is not flowing oil to the bearings, the bearings will fail. The gauge is our way of knowing that there is oil in the system, flowing to the bearings, valve train, and cylinder walls. Hate to sound so harsh, but that's the way it is. And, of course, hopefully, your engine is fine.

Did you hear it knocking?

I changed the oil. There was 2.5 quarts of oil. I am going to take a look at the filter tomorrow. There was no knocking, the engine sounded like normal.

Dandy Kiwi said:

I changed the oil. There was 2.5 quarts of oil. I am going to take a look at the filter tomorrow. There was no knocking, the engine sounded like normal.

Click to expand...

If you cut the filter, a good sharp chisel works well. Don't use a saw or you will end up with particles from the can in the filter.

Sent from my XT1585 using Tapatalk

Dandy Kiwi said:

I changed the oil. There was 2.5 quarts of oil. I am going to take a look at the filter tomorrow. There was no knocking, the engine sounded like normal.

Click to expand...

Hopefully you dodged a bullet!