Does GM use a lighter oil for break in? My oil pressure on my new truck is a lot less then it was on my 03 with Mobile Delvac 1.


Any other ideas why it might be so much lower? My guage is in Metric so I'm not going to bother telling you how low. http://www.dieselplace.com/forum/smileys/Clown.gifEdited by: Max Power

My 04.5 has been running 30lb idle and about 60lb on the highway from day one with GM oil, Rotella-T 15W-40 or Rotella-T 5W-40 syn.

Jim

It is hard to say because mine is in metric but I think mine is actually lower then that.

How many points pressure is it at the 1/2 way point on the guage?


Mine runs abot 2 or 3 needle widths below the 1/2 way point on the highway and a couple needle widths about the red line at idle.Edited by: Max Power

Max,


Sounds like yours is a bit lower than most, depending on what the conversion factor is.


Mine uses the middle hash mark for sixty psi. and the first hash mark is, I'm assuming here, thirty since it's in the middle of the first half.


Mine ran a needle width under sixty at cruise and a needle width under 30 at idle with the factory oil. It's got Delvac 1300 dino in it now and it's right at 60 during cruise and the idle is still about a needle width under 30.


Hope that helps.

You switched to Mobil Delvac 1 for break in ? The factory fill I'm sure is 15w 40.


I would stay with the 15w 40 Dino for some quick changes.I know I know they argument on Dino verses Synthetic for break in as the Corvette and others come factory filled but they ain't diesels either.


GM has addressed the High Oil Pressure as far as I know due to the excessive pressure at cold start up.


Mac Edited by: Mackin

Mac,


If the question is for Max, I think he's comparing what his '03 had with the Delvac 1, to his new ride.


If the question is for me, I switched to Delvac 1300 which is still dino oil and a 15W-40 rating.

My 04.5 has been running 30lb idle and about 60lb on the highway from day one with GM oil, Rotella-T 15W-40 or Rotella-T 5W-40 syn. Jim


My 2004.5http://www.dieselplace.com/forum/smileys/Heart.gif runs 25lb idle and about 55/60 on the highway from day one and for the past 7000 miles.http://www.dieselplace.com/forum/smileys/Hug.gif

Hello all, I'm new to this and new to the 2004.5 duramax. I found that the knocking was gone at high oil pressure, once it got warm the knocking came back. mine is at 25-60

thats about where mine runs as well, during break in and after with synthetic - now that its mentioned im going to check it more closely but im pretty sure that it runs right at or below 30 idle and righ about 60ish freewayEdited by: tbone1227

MP


Fellow canuk here,


Mine runs at a bit over 400 kpa when cold and settles in at about 400 when warm at highway speed 65mph.


Idle when warm is about 150 to 175 kpa


Using Rotella 15-40


I have a bit over 8,000 kms now. 2500 with the "Max Mod" and "Fingers fix"





Rob

Forgot, here's a link to convert kpa to psi


http://www.ex.ac.uk/trol/scol/ccpress.htm


Rob