I have a 2003 Duramax with 20,000 miles on it and was concerned about the lack of oil pressure. The gauge carries around 25 when hot @ idle and 65 when
running down the road. Is this normal for these trucks or not? I thought the truck carried more pressure a year ago then it does now as I don't drive the truck much and can't remember.



:help:

I think thats about right. Changed the oil lately? what kind?

Could be from changing temp. I know during the cold months running reg. dino 15-40 my oil pressure is higher than during the summer months.(thicker oil in the cold) That # seems a bit low, but not much lower than what I'm seeing.

They ran higher oil pressure IIRC on the 01 and also 02. Mine runs close to 30 when warm idel and 65 ish at 2k. This is with 15 40, summer or winter dont matter really. 46k on my truck

Thanks for the info. I run 15-40 schaeffer oil (www.schaefferoil.com) all year round and change the oil every 5000 miles. I guess I was comparing the reading to my old 02 and it did carry a lot more pressure and so does my father-in-laws 01.

I have a 02 with 26,500 miles, I've been running Amsoil 15W-40 Marine Syn since 5,500 miles, and just recently my oil pressures are up from previously reading the gages, a oil change or two before, my idle went way down to 35 or below and now it's over 40 at idle, and driving down the hwy at 2,000 rpm I'm running at 70 psi, that's a difference..... I'm wondering why???

The gauge on my 01 acts like a boost gauge, on a hard accel. it'll hit 70-75 and then back down when you let out on it

Mine are about the same. Around 25-30 at idle and 60-65 at highway speed. According to other posts it sounds normal. (Unless as you said it actually WAS higher before, a change could be a symptom of something.)

Sounds normal ...but does make you wonder huh? First rig I've had where oil pressure drops 2/3 at idle.

Scared me too! Just got my '03 last week and saw oil pressure swing on the way home from the dealer. First thing I did when I got home was log-on here and search old posts. Found that it is normal. BIG RELIEF!!!

I've watched my oil pressure pretty closely for the last few hauling trips. Your pressures sound normal but if you watch more closely, you'll see the pressure changes quite a bit with RPM. When you haul though, you will notice under load the pressure will drop some for the same RPM. This is due to EGT. There is another thread about this.

it sounds normal. that's right in line wtih my 02 lb7

Is it normal say when you first start your truck in the morning for the pressure gauge take a second or two to register? 15 40 castrol. Thanks

yes it's normal for the oil gauge to stay at 0 for a second or two. Also the pressures stated are about right as well for what I've seen. Oil type also makes a slight difference on my truck, as do ambient temps. However, if I'm out of the red I don't worry and I doubt that any of the factory gauges are 100% accurate.

I checked mine this morning, after the engine was fully warmed up and oil finally warmed up it stayed at about 25-30 psi @ idle and 60- 65 psi above 2000-2500 rpm and varied with rpm. 04 LB7

I have a 02 with 26,500 miles, I've been running Amsoil 15W-40 Marine Syn since 5,500 miles, and just recently my oil pressures are up from previously reading the gages, a oil change or two before, my idle went way down to 35 or below and now it's over 40 at idle, and driving down the hwy at 2,000 rpm I'm running at 70 psi, that's a difference..... I'm wondering why???


Have you changed your brand of oil filter. I used to use puralator and it seemed my pressure was slightly higher. Now I've been using the AC's and its prettly much in line with 4020's. I was wonder how much of an impact the filter would/could have on oil pressure??......Bill

I have a 02 with 26,500 miles, I've been running Amsoil 15W-40 Marine Syn since 5,500 miles, and just recently my oil pressures are up from previously reading the gages, a oil change or two before, my idle went way down to 35 or below and now it's over 40 at idle, and driving down the hwy at 2,000 rpm I'm running at 70 psi, that's a difference..... I'm wondering why???

):h My 02 runs very similar to yours... about 40 psi at idle and 75 to near 80 psi at highway speed. I too run 15W-40 Amsoil synthetic.

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I checked mine this morning, after the engine was fully warmed up and oil finally warmed up it stayed at about 25-30 psi @ idle and 60- 65 psi above 2000-2500 rpm and varied with rpm. 04 LB7

Ditto: :exactly: