I changed my oil yesterday except the filter couldnt get it off and didnt have an oil filter wrench. Someone over tightened it or something. Before I changed the oil I would get about 20psi or so at Idle and 40psi driving. I put in 15w40 Castrol diesel oil and most of a Lucas Oil Stabilizer bottle in it. Started it up after I put in new oil and it would be about 30psi idle for awhile but it moves alot sometimes its at 30psi then 20psi and dips down to like 5psi. Is the gauge messed up or did I screw up the engine. Driving it says 30-45psi depending on what the gauge feels like saying. Any suggestions?

thats low oil psi mine has 38psi hot idle 51psi hot driving pegs my 80psi gauge cold id check your oil sending unit back of engine top left center you might have a loose connetion i had same prob about a year ago hope this helps you

Its possible its a loose connection cause it does have an oil leak.

Sounds to me like maybe the gauge is messed up... I can't think of a good reason why the oil pressure would fluctuate like that unless you've got a bunch of sludge going around in there for some reason...

well that lucas stuff is pretty thick stuff so that might be it.

Yeah, I've used that stuff and it is pretty thick, but once it mixes with the regular motor oil it basically just makes all the oil a little bit thicker. I suppose if it didn't mix very well it could do that...

Im thinking it just needs more time to mix in there.

I wouldnt be suprised if my gauge was broken either since the water temperature gauge doesnt seem to work either.

sounds like you need to get a new sending unit for the gauge. my engine runs 80 psi cold, and about 60 warm.

Drove it around some more and it was fine for awhile and then it gets like a thick spot and oil pressure drops to 10psi for like 5-10 minutes and all the sudden it pops back up to 20-40psi. I think I just put to much lucas oil stabilizer stuff in there cause its pretty thick stuff.

Factory gauges are not very accurate, I would install a good aftermarket oil psi gauge and see what readings you get then. Stewart Warner, Isspro, Autometer,etc all make good accurate reading gauges. Until you verify your oil psi with another gauge I would not put much stock in the readings you are now getting. JMO.

P.S. mechanical type "live" gauges are more accurate than electric gauges that use a sending unit and wires to the gauge.

When I get my tax return back I am going to replace all the factory gauges with aftermarket autometer ones.

This is my first post on this site, When I first bought my truck in 1990 it was five years old , one of the first things to go out was the iol sending unit, I took the old one to the parts store with me and the parrts man said it was for a 60 psi gauge. Be fore it quit the gauge almost pegged but after the new sending unit it reads about 45 to 50 going down the road and about 20 at idle with 312000 miles on the ODometer.

i've used lucas in many engines and never had it fluctuate the oil gauge. I still vote to go get a new sending unit and try it.

Im probably going to go get a new one. Thinking of getting some mechanical gauges because I dont trust electric ones that much. especially for the oil pressure one. Need new ones anyway since the water temp gauge always says 100 degrees and never moves.

Lucas shouldn't make it fluctuate once it mixes. It sounds like your sending unit is messed up.

Personally, I would just ignore it. The oil pressure gauge in my truck has been broken for ages... It shows 0 psi at idle and 20 at speed (sometimes 20 at idle an 0 at speed ):h ) and every now and then it will hit the peg one way or the other for no apparent reason. :eek: ):h I keep meaning to get rid of it and install a mechanical gauge, but I haven't gotten around to it yet...

I once installed a new oil pan upon a 6.2 diesel for a friend of mine and before i changed the pan,the engine had lots of oil pressure.The guage was pegged at cold startup and was halfway when warm.So anyway i installed a new pan and filled it with the correct quantity of oil.I fired it up and it had 0 psi on the gauge.I could'nt understand why.I shut it off and then installed a remote oil pressure gauge tester in the oil sender port.I fired it up and still nothing.So i started thinking of what could be wrong.I had'nt touched the oil pump,screen or anything like that.No shop rags in the new oil pan either......lol.:D So i dropped the oil pan and had a look at the oil pump.I took it apart on the workbench and it was the most badly worn oil pump i had ever laid my eyes upon.One of the inside gears was scrubing the housing very badly.I could move the gear from side to side.So i tossed the old pump and in with the new.Still had me thinking though why the engine had any oil pressure at all with such a bad pump.

Its starting to work again sort of. Consistant at 30 psi pretty much must have pumped something offroading today cause after awhile it started reading 30psi instead of 10 after a good bump. Hopefully I can get some pictures from my friend of my K5 3 wheeling. Up on some rocks with one wheel in the air. This thing does pretty well for stock height with 31" tires up front and 32" in the rear. High centered a couple times but the posi rear helped me out a bit. Need to lock it up all the way and lock the front but man its fun.