Low oil pressure

I went through my engine a couple of years back; replaced rings, bearings, cleaned things up, etc. I inspected my oil pump at the time and it looked okay. It's the twin counter-rotating gear type. I've got an external oil filter and oil cooler plumbed in downstream of the pump.

Ever since I got everything put back together I get minimal oil pressure readings. I don't know what was normal before the rebuild because the Jeep was new to me and the engine...well the engine needed a rebuild. I put in a brand new electronic gauge with the prescribed sending unit from Whitney. I get maybe a 5psi reading when the engine is cold and at idle. Once the engine warms up and oil thins out I get nothing. Running down the road at RPM I get a reading of about 5psi.

I've been running the engine for a couple of years with this problem and I have to believe that the problem is with the gauge because otherwise I'd have seized up before now . The engine runs like a top and doesn't have any overheating or other problems. Does anyone have any experience with this kind of thing? Any suggestions for troubleshooting? If I wanted to put in a high performance oil pump, or a stocker for that matter, any suggestions on where to find one?

 

Ug! My V6 siezed suddenly from that very thing.

Try un hooking the gauge, or the entire sending unit from the block. If there truly is no/low oil pressure, oil will dribble out a drop or 2 at a time. Hopefully it'll shoot out tho, so pray for a mess to clean up.

Other things: Make sure the dist is anchored down really good, and consider pulling the pan...perhaps the oil filter disintegrated and is now plugging the pick-up screen (BTDT ).

 

I would check itwith a manual gauge even if just for test purposes they arent expensive and it only takes a few minutes to hook up. Then you can actually see the oil being pumped up to the gauge. Just my 2 cents

 

x2

 

I second the Melling High Vol Pump.
My 231 had about 15lbs at startup and would drop to 0 after being nice and warm. It always ran ok but the bad scary thoughts were always there. I overhauled the motor, installed new bearings and the old ones measured just fine very little wear. I then found that the crank had been ground at some point and that these must have been relatively new bearings. I went ahead and installed my Melling pump, very straightforward but be sure to prime it with vaseline or something...(derrr, silly me). Anyhow for a cheap cost it was nice and easy to do. I used the settings for 60 psi and after install that's what my gauge reads...so either its putting out more pressure than it should and my gauge is bad or the old pump was pooped..... hope my experience helps!!!

--Jake

 

X2 with the manual then a Melling if needed.

 

x3, install a gauge on an oil passage or tee off the sending unit. that 5 psi is not right. Things start rattlin'R) by the time you get down to 15psig.

 

When I built my new 225 I put in a Melling High Volume pump. With a brand new electric pressure gauge I had the same experience you have had. I could tell by the sound of the motor I had oil pressure but wanted a gauge that I could look at. I put in a mechanical gauge and bingo 50 + pounds. I don't know why the electric one wouldn't work but it didn't.
You can preload the relief spring to get any pressure you want but you need a working gauge.