So I thought I might be burning oil, at the rate of 1 quart in about 500 miles. There is no grey smoke, maybe a little but so little that I am not sure. There isn't any blow-by coming out of the tube nor the oil cap. After I filled it the last time it has been fine for the last 600 miles as I have been checking it frequently. It seemed good to go so I haven't checked it in the last 100 or so miles, then today I happened to check it and down a quart again! I am at a loss, the engine has been rebuilt, bored .40 over and has roughly 10,000 miles on it. It isn't like it has been slowly going down, it dropped to the 1 quart down mark almost overnight it seems? No drips, spray or anything. I am at a loss, help!!

 

Do you park it in the exact same place all the time when you check your oil?

 

Most of the time to make sure it is level, but it does vary sometime.

 

Have you recently change oil brands? If not try changing what brand of oil that you are using. Oddly as that sounds it may help. FYI you won't notice a quart of oil burning off in your exhaust smoke in 500 miles. You might if it is going through it every 100 miles.

 

That's just it though, I have only owned the truck for about 1100 miles, and changed the oil to the brand that I used on my last 2 trucks (Rotella 15w40) It didn't burn any for 500 miles or so, and then after another 100 it is gone? It isn't like it slowly lost it down the dipstick, it was just down a quart. It did it right after the oil change as well. after 500 it was down a quart and I filled it, now 600 later down another quart like I described. I figure I would see some blowby or something if it was going through it that fast...

 

I can't even notice a quart low in these diesels. Are you sure its only a quart? If its down low on the dipstick, its gonna be more than a quart low.

 

It is halfway down the crisscross section of the dipstick. IT was at the top.

 

Checked the turbo, actually the intercooler tube and nothing. With it running this morning, there was some white smoke or steam coming out of the oil cap and some out of the breather tube, however, it was colder (about 50) and the engine was cold. Also, I couldn't see the smoke coming out of the breather tube unless I put a flashlight up against it. There is some oil in the tube, but nothing dripping out, nor has there been since I have owned it. Nothing on the undercarriage either. Is the smoke a sign of blowby or would it be REALLY noticeable if I am going through a quart in such a short amount of time? Was it due to the cold that the smoke or steam was coming out the cap and tube? I also pulled the oil dipstick while it was running and nothing came out.

 

I am far from an expert but ......... if you have good compression, no blowby or leaks then about the only place oil can disappear is through the turbo bearing out the exhaust as burnt oil. If you had to rebuild the motor then chances are you should have rebuilt the turbo. Turbos can get really hot in the hands of the unknowing.

 

I have seen engines that drop a quart of oil then stay there. Add a quart and it drops right back down then stays there. Like I suggested earlier, try changing the oil brand and see if that helps. Even though you have had great luck with the Rotella try another brand just to verify.

Keep us posted.

 

Exactly where on the dipstick are you trying to run the oil level at? The dipstick on an engine is basically just a guide or for reference. These engines use vehicular pans so be careful about adding extra oil. You could possibly be spilling over into the shallow section of the pan. If this happens, you could actually add several more quarts without much reaction on the dipstick.
What I would suggest is to drain the engine oil, replace the filter and add exactly 12 quarts of oil, no more. Start the truck up, drive it for 10-20 miles and return back to where you are going to check it at. Allow it to set for 1 hour and pull the dipstick. When you pull the stick, do not twist it and read both sides. Do it again the next day, then again the next day. It could be something as simple as the factory dipstick tube (inside the engine) got bent during the engine rebuild.