When I start my eng.it takes about 1to 1.5 sec.for the guage to register any pressure.Once it does it goes straight up to 3/4 scale and stays there no matter what r.p.m.s I'm running.Question is ;shouldnt the oil pressure be more immediate or is it just the stock guages that lag.also i'm not sure if its related but it takes a few seconds. for the eng. to start.I'm just thinking out loud but could it be a possibility that the LPOP isnt feeding the HPOP well enough to get it started quicker.ANd therefore maybe robbing the oil press.Maybe totally off base but i'm new so i'll use that excuse.

 

This doesn't sound like a problem to me unless you are seeing it for the first time or experiencing some sort of new performance issue. If it does this all the time hot or cold and runs fine otherwise, no problem.

 

I believe this is normal. My truck acts exactly as you describe.

 

Once I start my truck my oil pressure gauge goes to 3/4 and doesn't move, not like my 460 gasser, I would watch it go up and down depending on the temp and rpm's

 

O.k. it's just my paranoia.There are no other concerns that could go along with it.So I just need to get out of my head.thanks all

 

<TABLE cellSpacing=0 cellPadding=3 border=1><CAPTION>

As per Spec, here you go on oil pressure. The gage in these is only a pressure switch, either you have pressure, or you don't. I know i have seen the spec on that, but can not fine it for the life of me now. I want to say it was in the neighborhood of 5 psi. So basically, either good, or your screwed.


Oil Pump, Oil Cooler and Oil Capacity
</CAPTION><TBODY><TR><TH vAlign=bottom align=middle colSpan=2>Oil Pump Pressures</TH><TH vAlign=bottom align=middle colSpan=2>Engine Oil Capacity</TH><TH vAlign=bottom align=middle rowSpan=3>Oil Pump Drive Gear Radial Clearance</TH><TH vAlign=bottom align=middle rowSpan=3>Oil Pump Drive Gear End Clearance</TH></TR><TR><TH vAlign=bottom align=middle colSpan=2>Engine at Normal Operating Temperature</TH><TH vAlign=bottom align=middle rowSpan=2>Liters</TH><TH vAlign=bottom align=middle rowSpan=2>U.S. Qts.</TH></TR><TR><TH vAlign=bottom align=middle>Curb Idle</TH><TH vAlign=bottom align=middle>3,300 rpm</TH></TR><TR><TD vAlign=top align=middle>69 kPa (10 psi)</TD><TD vAlign=top align=middle>276-482 kPa
(40-70 psi)</TD><TD vAlign=top align=middle>12.3</TD><TD vAlign=top align=middle>13.0</TD><TD vAlign=top align=middle>0.71-0.81 mm
(0.028-0.032 in)</TD><TD vAlign=top align=middle>0.02-0.08 mm
(0.001-0.003 in)</TD></TR></TBODY></TABLE>

 

The pressure rating for that switch/sending unit is 7 psi. Like FN said, it's either all or nothing, it won't move like your old 460 did. Also, the switch is located in the lid for the HPOP res, being the highest place on the engine to receive oil.

Everything sounds normal to me.

 

Well as for the factory gauge, it is just an indication that you in fact HAVE pressure. I put a mechanical gauge in mine and at idle just after a cold start, I sometimes see over 60psi and if I drive it slowly getting up to the main road, it can flux up to 70-75, while the factory gauge stays rock solid and never moves. When it is full operating temp, at approximatly 2000 rpm where I run when I tow, it stays rock solid at 55psi. When I get off the interstate for fuel, it drops to about 20. 20 is the rock bottom lowest I have seen hot at idle. All you have to do basically is bump the go pedal slightly and it springs right back up to the 45-55 range and full 55 just about 1200 or so (rough guess)..I run rotella 15w40 year round since South Carolina is not that cold in the winter and I rarely drive it except to tow the fiver to the races in the summer months...actually february to october....Wow racing season is pretty long after all....Just my 2 cents worth...Dave

 

Dave, where is your sending unit located? That sounds like bottom end pressure to me. The pressure in the HPOP res is actually lower than the bottom end. I've got sending units in both places on mine and a switch to toggle between them. Not that it matters, but the HPOP res won't see more than 25 psi when hot. At hot idle, it will drop to 10-12 psi. On the bottom end though, I see the same numbers you reported.

 

I tapped into the filter housing. There is a plug I removed down on the oil filter housing. If you are looking at the filter..looking from drivers side to passenger side, there is a plug on the left side, or toward the front of the truck. I removed this plug and that is where I plugged in for the ISSPRO mechanical gauge. That is I assume the common place for tapping for oil pressure, but if I ever go to a bypass type oil filter I may have to find a new place, or put a "T" in there for that? Hope this clears up stuff...Dave

 

In the airplane world, the time limit that a recip (internal combustion) engine can run safely without oil pressure is 30 seconds. It should be about the same for all recip engines. Plain (main) bearings are plain bearings. I know it seems like an eternity, but it really doesnt do any damage. My 01 7.3 PSD does the exact same thing.

 

You can put the sending unit here, for the same reading as you have now. Click for larger version:

 

I didn't realize that that little square plug under the down pipe was an oil plug. That is definitely good to know.....Thanks a bunch....

 

What is that black flex line just aft of the filter and forward of the oil pressure sensor? I noticed I have a square plug where you have that line. I would assume it is for another gauge? Thanks for the info...Dave

 

The one going directly into the block? That's actually the return line for the Oil Guard bypass filter. Pressure line to the OG is taken from the oil filter housing, where you have your pressure sensor now.