i bought a 98 3500 a few months back and engine oil pressure runs about 70 psi at start up and drops to about 60 psi or a little more when warm. is this normal? i know good oil pressure is good but is this too much? thanks

Sounds about right. Startup pressure is always higher since the oil is colder and thicker, there is more resistance to push it through the engine so the pressure builds.. On winter days you might see up to 100psi initially. After it is warmed up it should be about 40-60psi. A gunked up oil cooler or dirty oil filter can keep the pressure in the higher bit of the range and a perfectly clean system will be lower.

Oil pressure sounds a little high to me. Have you put a mechanical guage on the engine to verify actual engine oil pressure and your in cab gauge is reading correct pressure?

Sound about right... But I got a video you might want to look at...

http://www.youtube.com/watch?v=bUYO-lJe36w

Suggest you use a machanical gauge to test...

ill try a manual gauge. in the video what is the switch that the dude is flipping? when he flips the switch that is about where my oil pressure is when the engine is warm, even higher when cold... thanks a bunch guys.

ill try a manual gauge. in the video what is the switch that the dude is flipping? when he flips the switch that is about where my oil pressure is when the engine is warm, even higher when cold... thanks a bunch guys.

It is a coolant temp fooler. Cons the ECM and gauge into thinking that the engine is still cold.

ill try a manual gauge. in the video what is the switch that the dude is flipping? when he flips the switch that is about where my oil pressure is when the engine is warm, even higher when cold... thanks a bunch guys.

It is a coolant temp fooler. Cons the ECM and gauge into thinking that the engine is still cold.

I'm the one the that did the video... As for the switch in from ECT fooler that controls my high idle and 3 cyl high idle. Check it out... http://mopar.mopar1973man.com/cummins/2ndgen24v/high-idle/high-idle.htm

Where do you hook up the mechnical gauge to measure oil pressure :shrug:Also ...... how much blowblack when the engine is hot ? I have almost none when cold ........... but once warm ...... can definately see it from the 'crankcase modification' running to bottom via pvc pipe - but how much is normal ?

Where do you hook up the mechnical gauge to measure oil pressure Also ...... how much blowblack when the engine is hot ? I have almost none when cold ........... but once warm ...... can definately see it from the 'crankcase modification' running to bottom via pvc pipe - but how much is normal ?

On mine there is a 1/8" NPT plug on the top of the oil filter mount, probably be the easier place to do a test gauge. As for how much blow-by, this was on a thread a while back: You need a blowby tool. The Cummins blowby orifice tool is simply a tee with one .221" (15/64-in) outlet. Connect one end of the tee to the end of the blowby tube. Put a manometer on last tee outlet. That is your blowby tool. They sell them at the Cummins, but I have made my own plenty of times, less than $10. A simple manometer can be made by looping into a 'U' 6 feet of clear tubing with water in it half way. Measure how high the water level rises with a tape measure, multiply it by 2, convert it to LPMs. Rough conversion is 1"= 27 lpm, add 3 lpm for each one inch (1/2'' of rise in the tube) of water The reason for multiplying by 2 is that inches of water equals the water rise in the open end of the tube plus the inches the water is pushed down on the engine side of the water tube. For simplicity my numbers below are the measurement of rise only. Cummins new 5.9 engine numbers are: 63 liters per minute(2.5" water rise) @ 2200rpm, 76 L/Min (3.5" rise) @ 2500rpm 85 L/Min (4.5" rise) @ 2800rpm. Worn engine that needs rebuilding are roughly double i.e. 126 L/Min(10.5"rise) @ 2200rpm 152 L/Min(14.5"rise) @ 2500rpm 170 L/Min(17"rise) @ 2800 rpm Beside indicating a compression problem the valves could also be out of adjustment. Another way (mine), same idea, is to block the blowby tube with a 1/2'' pipe nipple with a cap that has a 15/64 hole drilled in it. Use 3/8'' id looped clear tubing with water in it slipped over the oil dipstick tube. Other tubing end remains open. Use a sharp tipped felt marker to mark the water level with the engine off, have a helper start an already warmed up engine and run the rpms up to 2.2, 2.5 & 2.8k rpms. Mark each water level with the pen, measure the distance from engine off mark then multiply each by 2. This is all very simple to do, just hard to explain with words.

I have made my own plenty of times, less than $10. A simple manometer can be made by looping into a 'U' 6 feet of clear tubing with water in it half way. Measure how high the water level rises with a tape measure, multiply it by 2, convert it to LPMs.

Sweet - no that made sense. Only question is - does it matter what ID tube you use ........ and can you connect it to the pvc pipe anyway you want as long as its a good seal ? (going the homemade way) ?

Sweet - no that made sense.

Only question is - does it matter what ID tube you use ........ and can you connect it to the pvc pipe anyway you want as long as its a good seal ? (going the homemade way) ?

Tubing size won't matter, pressure will be the same regardless. Not sure on exactly how you make the "U". I will start searching.

---------- Post added at 06:35 PM ---------- Previous post was at 06:19 PM ----------

Alright here is what I was able to come up with. Had to draw a pic for this. You try to keep the U part as vertical as possible without kinking the tube seeing as how that's how it measures. The less vertical it is, the more off your measurements will be because it is easier to push water out of a hose that is on an angle, or horizontal for that matter.

http://www.mopar1973man.com//isx97/Truck%20Stuff/Ryan's%20Dodge/Modified%20Pics/Manometer.jpg

Fine I will add a more appropriate picture!

awesome Only thing to add was "I wish that was my truck" - hahah thx dude