Changing engine oil in GMC Duramax

[WVH1977]

I inherited a 2007 GMC 2500HD Duramax from my father when he passed last year. I had the oil changed and fuel filter changed after I got it at around 122,000 miles. My local mechanic uses Synthetic Amsoil and put 127,000 miles on my sticker for the next oil change. I am at 125,000 right now and my truck is telling me to change engine oil soon. The oil is at the full mark and does not look to bad. Do these trucks automatically tell you to change the oil at every 3000 miles? Also, should I go ahead and change it anyway? I thought you could get longer milage between oil changes when using the synthetic oil. The last thing I want to do is hurt the engine on the truck.

Any advice or suggestions would be appreciated.

 

[WilliamBos]

Did the mechanic reset the oil life monitor?

 

[rustyshakelford]

I do 10k oil changes on my trucks. If concerned, send a sample in to black stone labs. They will get you lined out

Brett

 

[WVH1977]

Did the mechanic reset the oil life monitor?

Good question. I have no idea if he reset it. I am going to give him a call tomorrow. That is probably it.

 

[Gary Fowler]

I was told by the dealer that those engine oil life monitors are set for regular oil and they don't analyze the oil, just the engine info like how hot the engine got, how many RPM it turned and what ever else the computer can calculate.
Anyway, the oil life monitor has to be reset at each oil change for it to work even with dino oil. I suppose with full synthetic, you could just reset the computer and let it run another cycle since the are supposed to be good for at least 15K and Mobil 1 is advertising 20K between changes.

I used to change my oil every year but lately, I just wait for the engine oil life monitor to say change it. I run full synthetic (Shell Rotella T6) in everything.

 

[gsganzer]

The oil life monitor is just an algorithm, there's no actual oil analysis. It's calculated off of miles, RPM and temperature. On my Ford F150, I can select the % to start the oil life calculation.

 

[DieselBound]

Synthetic Amsoil and 5k change intervals? Wow!

I got a VW TDI (2000) that had had its oil changed just like that. Overly expensive oil at 1/2 the factory recommended change interval. This was great for ME (engine was in really great shape), but not so great for the previous owner (shelling out all that $$).

Rotella T-6 or Delo 400 LE 5w-40 are good CJ-4 oils. If CJ-4 is what is spec'd for these engines then just go with one of these. As noted above, if there's a concern just send an oil sample to Blackstone Lab.

 

[dieselcrawler]

The oil life monitor is easy to reset if the dash message annoys you. Turn key to run position but do not start, depress accelerator pedal fully to the floor 3 times in about 3 seconds, then turn key from run to start, allowing motor to start. Let it run a little then turn off. Should be reset to 100% oil life. Gets rid of dash message, go by your preferred mileage intervals. I run regular Rotella 15w40 at 5k changes in my Ford diesels. Could probably go longer, sometimes do, due to life circumstances, but I aim for 5k.

Diesel oil picks up alot more soot than gas motors, and for that reason I do not like the idea of longer oil change intervals. The oil may not be broken down yet, but is so contaminated with soot that I prefer to change it at 5k, using standard dino oil. Synthetic has its place, if you like... in gas motors, where the longer changes make use of the expensive oil, without the soot contamination.

 

[DieselBound]

If you have particles of concern in your oil then that's what the oil filter is for. Soot in oil is, as you note, a bigger concern for DPF systems: this is why CJ-4-plus exists.

Price-wise it's about a wash between conventional oil at 1/2 the manufacturer's interval (but, wait!, wasn't my comment about the OP's father spending for full synthetic at 1/2 interval?) and synthetic at full interval. Difference then comes down to time: labor and machine downtime. As they say" "Time is money." Nice to have oil options, I'm a busy guy!

 

[1stDeuce]

The oil life monitor is not set at any mileage, they run an algorithm based on a LOT of things. You can't turn the monitor off, you can only reset it. It is highly unlikely that your mechanic reset it when he changed the oil. I tend to forget to reset mine too, and it'll go almost two of my standard oil changes before it tells me to change the oil. (If you have the steering wheel controls, you can scroll around and see the %age, and reset it there. I don't)

Since I go by mileage, and I forget, and I don't care what it thinks, I just reset it whenever it pops up. Turn the key to run, stomp throttle to WOT three times, and it'll say "oil life reset". Done.

Just so you know, there's also a monitor for fuel filter. Since you just changed it, reset it too. Key to run, step on the brake and hold the throttle to the floor for 10 seconds, you'll see the fuel filter life reset" message.

FWIW, I change the oil between 6 and 8k. I'm running a gallon Rotella T4 and one of T6 at each change. (T6 helps with cold starts in the winter, and probably with high temps in the summer too...) I change it sooner if I work it hard a lot, and extend changes if I mostly do highway driving. The monitor often takes about 10k to tell me to change the oil. I'm at 245k now, with no end in sight, and zero issues with the engine, or the rest of the truck, for that matter. These are GREAT trucks!