Wildwisc

I have a'95 3.8L that I just put a new engine in. Today was "the day" and I started it for the first time. She started great but the oil pressure gauge was reading no pressure at all. I let it run for about a minute to see if any pressure would build, but got nothing. Shut it down, pulled the oil pump, packed it with petroleum jelly, and tried again. Still no pressure reading. I pulled the oil pump again, REALLY packed it full of petroleum jelly, and tried for a third time. The pressure gauge still read zero. What am I doing wrong? Any suggestions?

67mustang302

Did you prime the system? And are you sure the gauge works and is hooked up? Does the filter have oil in it?

Wildwisc

What do you mean by prime? The website of the company I bought the engine from had mentioned using a 40lb air tank to prime the oil but when I spoke with one of their techincianshe said that wasn't needed and that if I wasn't getting any pressure to pack the pump with jelly. I filled the oil filter about half full with oil. As far as I know, the gauge should be working. I bought it off a guy I work with for next to nothing because the engine was shot. Today was the first time I ever sat in it and turned the key.

67mustang302

Priming it is when you turn the pump mechanically while the engine is off. It pumps up the oiling system, and that's when you should be checking for pressure. An air compressor can be used to put oil in a tank under pressure to force it through the system as well. Are you certain the gauge works? And are you certain your bearing clearances are correct and all the galley holes are plugged?

Wildwisc

The second time I pulled the pump I really made sure the holes were all filled with jelly. How would I check the gauge to make sure it is functioning correctly?

pete1665

wouldn't you hear the lash adjusters clanking around if there was no oil pressure?

Wildwisc

What I did was pull the oil pump, pack the two gears with petroleum jelly and the galley holes. I replaced the pump and installed the oil filter which was over half full of oil. Then I removed the spark plug wires and turned the engine over. Still no pressure. When I pulled the pump after packing it the first time I noticed that itwas still full of jelly and there was no evidence of oil going through the pump. I believe that the gauge is working properly, as there is no evidence of the pump pulling oil.

RUDEDOG.357

If the oil pump drive shaft is in place I would look at the pressure relief valve in the timing cover. Ive had many 3.8l with stuck valves that take out crankshafts because it bleeds the oil pressure.

jjgt07

your turning your new motor over with no oil?? sounds like you will be rebuilding your new motor,oil is the lifeblood of your motor,i wonder what the crank bearings look like with no oil? oh boy, good luck,hope it turns out for ya!!