Hi! I am a new member so please take it easy on me. I found this website to be helpful for finding info on my rig but now I have a question. I have a 1990 Pickup SR5 V6. About 3-4 months ago I noticed that my oil pressure was dropping slowly over time. Last time I took if for an oil change the tech noticed the same thing but since the engine sounded good he said that it might be a bad gauge. It got to the point that it dropped to almost the very bottom line on my gauge but if I hit the gas it would go up but not near the spec levels but I figured its pumping either way since the needle moved. Anyways a couple weeks ago I started it up and heard a constant knocking sounds around the top valve cover area of the engine. I hit the gas and the gauge stayed on the bottom line of the gauge and didn't move a hair. I turned it off immeditately and haven't started since then. I believe it is my oil pump but wanted to get some feedback from everybody else. Thanks!!!

 

I am not sure about the V6's but if they are like the 22r/re design, which uses a mechanical oil pump, I would think it would be more likely something is stopped up then a mechanical failure with the pump. You may try pulling the pan and making sure the sump is not caked with something as a quick check. If my facts are straight I dont think the mechanical style oil pumps go out very often.

Thomas

 

Thanks! I was not sure what type of pump it was but some of the research I have done referenced the same as a potential problem.

 

You could remove the oil pressure gauge, hold a clear plastic coke bottle over the hole and have someone start it up briefly. If oil pressure is an issue, you will still have a clear plastic container as there will be little to no oil squirting from the hole. Also, inspect your oil for metal particles to see if your main bearings have been damaged.