Driving home last night, I noticed my oil pressure was below 30psi. That's in gear, at idle. I also seemed to be down on pressure at speed. I started thinking I have fuel in the oil. Oh boy.http://www.dieselplace.com/forum/smileys/Disapprove.gif I checked the level and it didn't look way high or anything. I pulled a fuel sample and sent it off this morning for analysis. I was planning on an oil change tomorrow anyway. Here's the kicker. This morning, everything was back to normal.


The details of the truck are this. It is an 02 with 37200 miles and 1480 hours. I run Delvac 1 with an Amsoil remote bypass. I saw a pressure drop when I put the bypass on and a little more drop when I went to the Delvac 1. I run around 30 psi when hot at idle and last night I saw what looked like 22-23 psi.


So now for all the questions.


1. What's the best way to tell (other than the analysis I'm waiting on) if you have fuel in the oil?


2. Are the any instances of oil pressure gauges or sending units going bad?


3. Should I take off my remote bypass and see if the pressure comes back up?


4. What's the minimum pressure before I should shut it down and have it towed in?


Thanks,


Chris

I don't know about the sending units on the DMax, but on a '91 S-10 Blazer that I had, the oil pressure started going all over the place. It would peg the gauge, then nearly drop to zero, might come back to normal, then peg again. Replaced the sending unit, and all was normal again.

Delvac made mine 14 idle and 54 hiway

Were you running hard? The oil is used to cool the underside of the piston crown, and can get pretty hot with a correponding pressure drop. Once it cools back down, pressure comes back up. Slower to cool idling than while running.

The old wick test .... Drop a drop or two on a paper towel check for wicking ....


Mac

I was not running hard. Actually, I was just kinda polk'n along to pick up the offspring.


I tried the wick test and couldn't really tell.


I changed the oil on Friday and the oil looked thin. I guess we will see what the lab says. The new oil seems to be doing just fine as far as pressure. I'll check tonight to see color, etc. She is running good, so http://www.dieselplace.com/forum/smileys/Confused.gif Should I just stand on it and see if it blows up?http://www.dieselplace.com/forum/smileys/Evil Smile.gif I won't do that, but ......

http://www.dieselplace.com/forum/smileys/Ermm.gifok, i too have probs with oil pressure dropping and the truck surging, was only at an idle at first, now it's while i'm running too. '04 dmax. chevy dealership here is horrible, don't know what to do. should i risk driving it to cali?

<TABLE width="100%" border=1>
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<TD vAlign=top align=left>
<UL =NONE>
<LI>Oil Pressure @ Engine Operating Temperature </LI>[/list]</TD>
<TD vAlign=center align=middle colSpan=2>


98 KPA, 14 PSI @ Idle</TD></TR></T></TABLE>this is the min spec for the duramax if pressure drops below this then you have a problem...

Chris, If you have fuel in the oil you will be able to smell it. I could smell it in mine when I had less than a quart in it. If you still have the oil, dump it in gallon containers and see how much you come up with, it will tell you real quick. When I had fuel in the oil, I noticed a very slight drop in psi but not much maybe 5-10 psi of difference, this is with Rotella dino oil though.

Okay, if the minimum is 14 psi, then the 25 I am seeing way too often is okay, right? I don't like the fact that I started at 40 when hot at idle and now I'm at 25. I was thinking about putting a regular filter on to see what that does. I am also considering going away from the Delvac 1, but that is dumping $80 in oil early. Anybody want to say what they would do if it were them? Eric, Sid, JK, any one of you brainiacs want to weigh in and tell me I am worrying about nothing?http://www.dieselplace.com/forum/smileys/Confused.gif Edited by: chuntag95

Mine has never been at 40 for idle. It always sits just below 30(from day 1).

I've got Delvac 1 in mine. Once it gets up to full temp, it will read just below 30 when at idle. By just below, the needle is almost touching the 30 mark. My oil system is totally stock. Before I switched to the Delvac 1, it would read just above 30 at hot idle.

Are all you guys reading the pressure off the gauge in the cluster,or have you got aftermarket gauge?? My pressure sits at just over 60 all day long....http://dieselplace.com/forum/smileys/Confused.gif

Depending on the outside air temp you will get different readings on your oil gauge. Here in Houston TX the outside temp is about 90ish


thewarmer the air going through your external oil cooler the lower the pressure. I'm not talking about extreme pressure drop but i have seen anywhere from 5-10 psi drop at higher outside temps....

After the first 500 miles or so I noticed mine dropped to 30psi or just below after the engine reached operating range. At 2000 rpm it's back to around 68-75psi.


Heck, it might even depend on the oil weight your running. I run 15-40 rotella.


Doug

I ordered a mechanical oil pressure gauge to see if the dash and it agree. I'll start there and move forward as I find out more. I am just having trouble deciding if I want to pull off the dual remote bypass filter or change to a 15-40 first (assuming the pressure is correct on the dash).

since new mine has idled one mark below 30PSI. I am running Delvac also and on a recent long trip when I would pull in it would be 2 ticks below 30. Doesn't do this around town just on that long hall.


Also I noticed while towing my fifth wheel that when pulling a grade and the engine starts wroking harder the pressure drops, soon as the load lightens the prssure comes back to normal (same RPM for both situations). I figured this is not normal and is probably the gauge acting up but if anyone knows different sing out.