[acannell]

2.5 turbo common block

just noticed that above 3k stock oil pressure gauge takes a nose dive and would probably go completely low if i held the throttle down

no visible oil leaks, no oil on the ground, dipstick shows mark almost at 75% to max

no audible clicking or knocking noises

compression test yesterday revealed 130 130 140 140 and spark plugs looked great

tried wiggling oil pressure sensor connector while idling and watching gauge...gauge stayed solid

checked all rod bearings and 1 main bearing a week ago (engine was apart) and they looked okay

piston and rings for cylinder #1 were replaced a week ago

i know for sure that gauge did NOT do this at least a month ago

what could i have forgotten to do? this is the 3rd time ive taken this engine apart so im not DUMB...

 

[tryingbe]

What does a mechanical oil pressure gauge say?

 

[turbokid]

my baron does the same thing. Your oil pressure sending unit is going south. I got a 15 dollar mechanical oil gauge and put it in and took it for a drive and had no issue. But when I get near WOT with the old sender it dropped off the edge.

 

[acannell]

INTERESTING

i just sprayed electronics cleaner on the senders plug and jack and now i can go up to 4k (parked) and oil pressure goes UP a little...

PHEW

im going to take it for a spin and see what happens..

tryingbe: good idea...looks like i need one more gauge in the cockpit...i dont have one yet though

i should also say..FWIW, that I unplugged the PCV tube from the valve cover and there was no oily blowby...

thanks guys!

 

[puppet]

Oil restrictor between the block and head installed? Head could be getting all the oil. The system will flow through the path of least resistance.



Bum oil filter could be the culprit too. Do like tryingbe said and rig up a mech gauge and slap it on the hood while you make a run. If it reads low try another filter. If not that, you have an internal problem. Could be a small piece jambed the by-pass open on the pump.

 

[acannell]

i think everything is okay...the gauge reads normal now, i think the connector had alot of oil in it and/or was loose..thanks for the help guys!

 

[phantomrt]

Had the same problem here--the first time I noticed it happening was after I pistfully passed 4 consecutive cars on my way home from work who were driving like constipated turds. I ripped by them and was doing 95+ mph, and once I got back in my own lane, I looked down and saw the guage at zero. That really got my blood pressure up, but luckily, I was familiar with the wiring circuitry to it and relaxed after I realized that if I really did have no oil pressure and the circuitry was working properly, the CHECK GAGES light would be on, too. It just so happened that 3000 RPM was the magical number for me, too. It was a NEW mopar sending unit, too. I worked with the electrical connector some on the harness and it never happened since.

 

[william]

+1 on sending unit, they do weird stuff like this all the time. Replace with a new one, get a mechanical gauge to be sure.