Oil Pressure gauge or sending unit?

[Avs_Fan]

Re: RE: Re: RE: mandatory reading

We noticed today while driving our 81 CJ5 Jeep that the oil pressure gauge was reading low. Previously during our drive I looked at it and it was fine. It is not completely low like it is not hooked up, but down around 20 and tries to go up to 40ish when given gas. It is really bouncy, not smooth or constant at all (like it was). What is it more likely to be the gauge or the oil sending unit? I went to our local parts store to get a gauge to try but they did not have one that would work with this set up. I am afraid to drive it now until I make sure it is not a bigger problem. Or are there any other ways to troubleshoot this problem? Thank you in advance for your advice...

 

[Sparky-Watts]

Where is Sully on this one?

Throw in a sending unit for good measure...they're cheap. If that turns out to not be the problem, at least you've eliminated one source and have a new unit to work off of.

 

[lah2420]

I would bet on the sending unit too. I'm on my third one.

 

[geopig]

I would bet on the sending unit too. I'm on my third one.

Ditto. And buy a good one (can't remember the brands right now). I had to replace mine, got the cheapy and had to replace it again 6 months later. The one I have now is going strong and it was only ~$15.

 

[Junkpile]

Sounds somewhat normal other than the bouncy part. Most of the CJs I have had do the same deal where the pressure drops to 20 at idle and rises as the engine revs. Heck, my TJ drops to about 22 at idle and shoots up to about 40 when I hit the gas. I've never seen one that was constant. How could it be constant?

I might be misunderstanding you though.

 

[LVRockCrawler]

RE: 249/242 swap

thats why i've always been a fan of the mechanical gauges - not just oil but water temp - wishin the YJ didnt have the integrated gauge set cuz i'd love to just put in a common "trio" set (oil/H2O/volt) but dont want to have dead gauges in the dash just to keep the fuel level... but in a CJ cant you mount a mech. gauge w/the tube going to the block and call it good? (thus eliminating the whole sending unit issue?)

 

[derff96963]

RE: Spool VS Locker

I would definetly second the use of a Mechanical gauge. That rules out the posibility of a loose wire causing it to jump. Mine btw reads about 50 all the time until the engine warms up. After that is does drop till about 25psi at idle and will go back up to about 50 at higher RPM.

 

[LVRockCrawler]

25-50 at op. temp is great ... my old 91 ran about there.. love to tell ya bout the 89 i have now but i'm having similar issues w/my gauge...

 

[Avs_Fan]

Thank you all for the replys. I replaced my sending unit last night ($19), the pressure shot right up to 50 psi and stayed there. I did not let it run long enough to warm up the oil to see if it would drop down to 20 psi like it used to at idle. I am putting this one in the books as the easiest repair I have made yet. Thank you all for the input. What a great message board!

 

[Sparky-Watts]

Re: RE: Re: RE: Laptop Stolen

Thank you all for the replys. I replaced my sending unit last night ($19), the pressure shot right up to 50 psi and stayed there. I did not let it run long enough to warm up the oil to see if it would drop down to 20 psi like it used to at idle. I am putting this one in the books as the easiest repair I have made yet. Thank you all for the input. What a great message board!

Glad to hear it!! I had pretty much the same problem before, only mine would peg when I let off the gas.

Yeah, we're the best board on the net, stick around, ok? :wink: