If the gauge only reads one voltage (reading) as you say then it wouldn't matter how much fluctuation was going on, the gauge would still read 30 psi no matter how mcuh fluctuation was going on. His gauge reads 2 different pressures.

 

i just went out and started mine, and it was settin around 50, crusing its around 40 i would say, and when i'am giving it gas, it goes to about 50-60. then when i let off to stop at a redlight, it goes down to around 30 or so, at the 1/4 line i would say.... sound normal to u all????

 

I don't think so, mine starts off at around the 3/4 mark and when I accelerate it goes to the 100 mark almost. Five minutes later it reads about where it should. Who knows, I just hope I don't have any problems with it while we are gone on our trip.

We leave Christmas day. Thanks Merry Christmas to All!

 

if pressure is pressure whether fluid or gas, why when you install a fuel pressure isolator, must you fill the gauge tube with glycol? gas will not transfer the energy as efficiently as liquid.

 

With the isolator you have a very limited amount of displacement by the isolator diaphragm. And you have a variable length on the gauge tube. So you must transfer the pressure completely within the limited travel of the diaphragm. In this case a non compressable liquid between the gauge and the isolator means you can have a tube of any length to the gauge and still get the full pressure reading before the diaphragm "bottoms out" against the housing. It could bottom out if the pressure got high enough on the gauge side. Bottom not because the gas would not transfer the pressure, but because the gas compressed enough to let the diaphragm hit the end of its travel. But on the engine side of the isolator it's simply a pressure reading. The pressure is supplied by the pump and has nothing to do with the oil being non compressable. Think of it as a constant. The pump feeds a volume of oil to the engine. The volume is dependent on the engine speed. When that volume causes the pressure to rise to a pre-determined point, the releif valve opens and holds the pressure at a constant. It's a dynamic process dependent on oil viscosity, engine speed, and the relief valve setting. If there happens to be a bubble of air somewhere in the system, the pressure in that bubble is the same as in the oil next to the bubble. Pressure exerts itself equally in all directions and, in a static situation, and eliminating the effect of gravity, is the same for all liquids and gasses.

Wetspirit

 

Hopefully the dealership installed the correct weight of engine oil and the correct quantity of engine oil.

Greg

 

OH SNAP!!!

 

um, the pressure gauge in the instrument cluster is just an idoit light. the sensor is just a switch, not a pressure transducer. on and off is all it can do. if your gauge is showing something, you have more than 6psi oil pressure.

 

My gauge also fluctuates depending on load. When cold, the needle will go a little above midway. After warm up, it will go there under load (accelerating, etc), but coasting or idle, then drop back down to the bottom of the normal range.

 

As long as you define "cruising" between 1-1200rpm and "giving it gas" as anything above that, that is the behavior I would expect to see from a healthy engine on a good mechanical gauge, with the exception of runnnig higher to around 80psi or so at rpm (giving it gas) for the first few minutes after cold start.

At least that's what I see on mine. Always have.

 

Some of the old cappillary tube type oil guages would take for ever to give you a reading because of the thick oil in a small tube.
That was an old aircraft problem that was fixed by the glycol in the tube exchange for a quicker reading in cold weather.
#50 oil in a small tube on a cold day is like grease.
The airplane would finaly show oil presure 20 minutes after take off and still show 20 lbs after landing and shut down 20 minutes later!
The first fellows post back last Christmas probably had a young fellow put 5-30 car oil in his cummins and I hope he has changed it out by now!

 

No, the original poster's sender was bad if you see his reply. From what I've posted here and in another thread, it seems that some of our trucks gauges do fluctuate, and it is normal. Mine goes up to 40+ on accelation and load, and then drops tot the bottom (left) of the "normal" range upon idling (after the truck has warmed up).

 

HEY ALL , MY OIL PRESSURE GAUGE STOPPED WORKING THIS MORNING ON THE WAY TO WORK .I FOUND CODE 1693 .i PUT IT INTO A REPAIR SHOP THINKING IT WAS JUST THE OIL SENDING UNIT ..THEY FOUND THAT IT WAS NOT RECIVING THE 5 VOLT SIGNAL FROM THE PCM OR SOMETING LIKE THAT?



ANY ONE WITH ANY THOUGHTS OR HAD THIS PROBLEM AND FIXED IT I WOULD LOVE TO HEAR IT..



THANKS .REDZ