oil Mysterious oil use

[gish03]

First post here, but I am in need of help. I just dropped my truck off at the local dealer for mysterious oil consumption. It is a 2013 GMC 2500hd with the 6.0 gasser. It doesn't leak enough to leave any puddles (rear main is a little wet but that's it) and it doesn't smoke at all. My truck is losing a quart of oil or more every 50-100 miles and the tech at GMC called and he has no idea why this would be happening. They're going to drive it to try and prove it's losing oil but i have found that one long drive doesn't seem to burn a lot of oil. It's after a week of my 2 mile drives to work every day and the occasional trip to the store and what not that I notice a quart has vanished from the dipstick. Please help

Edited May 14, 2018 by gish03

[Doug_Scott]

You don't say anything about your vehicle.  Makes it tough to be anymore specific than, your vehicle never warms up going back and forth from work. Without knowing how many miles you have on it I can't really offer anymore than wait and see what dealer finds.  

[Doug_Scott]

You may want to try warming the truck up before driving it the 2 miles and see what that does to oil consumption.  If you have remote start, use it and wait till it shuts off before leaving. 

 

You can also pull a spark plug after a long time of just going to work driving to see if there is any build up on them.  A long trip may clean them up so check before taking long drive. 

[Logroller]

Your consumption is excessive to me by no question. However, that is some serious short driving and is not making for good results, operating temps,  heat cycles, gunk build up, again my opinion and I don't own a HD.

 

With that said, just about everything with these trucks will result in oil consumption. I have a 6.2L 1500 and unless you do some constant good feather foot work, the computer gets a little wonky with 1 to 3 gears (clunky thingy people talk about.) I'm pretty good with the gas pedal in stop and go traffic, but grew tired of it's wonky shifting as mild as it is. So I tried manually shifting between 1, 2, and 3gears. It apears the truck ate some oil , maybe 1.75 quartes over 6,000 miles. Not a huge quantity by any means and still way within GMs specs for oil consumption. The previous 5K ate 0 oil and I'm only 1k in to the next oil change. Right now it looks like the manual shifting (higher revs and engine braking were the culprit). 

My point being, sooooo many factors seem to be potential cause of oil consumption just with normal use and without mechanical failure. 

I'm curious to your HD oil consumption. 

 

https://gm.oemdtc.com/698/01-06-01-011j-information-on-engine-oil-consumption-guidelines-2018-and-prior-gm-passenger-cars-and-gasoline-powered-light-duty-trucks

[Jsdirt]

Not sure whether to thank the EPA for the never-ending mileage and emission increases, or GM for using sub-par quality, cheap parts ... but the blame rests on the low-tension piston rings, used to reduce friction/increase mileage. Gone are the days of getting 200k+ miles before these engines start using oil. Mine started at 50k miles! If I keep the RPMs under 4k, and only hit 4k or higher for very brief periods, my oil consumption isn't too bad - roughly 5k miles per quart. If I set the cruise control while towing on a hilly highway, like 91 Northbound in VT, and let the engine scream to 4-5k for extended periods, it'll eat up a quart in 300 miles.

 

There's quite a few 5.3 oil burners due to the poorly engineered AFM system too. That didn't seem to be as big of an issue with the 6.0, however. Doesn't mean it isn't possible, though.

 

Seems we've reached a peak as far as quality goes ... and now we're heading backwards. Sad that the general public is fooled by the fancy interiors and electronics that hide the overall decline in quality.

Edited May 14, 2018 by Jsdirt

[gish03]

So I picked the truck up from the dealer and decided to try something out. I heard about all the issues with the 5.3 pcv orifice in the valve cover being a culprit of oil consumption, although I have a 6.0 but I have also read a couple forums stating the pcv orifice in the 6.0 is a problem as well. I figured I'd check my intake for oil since the truck doesn't smoke or leak at all I figured it must be pooling somewhere, so I took a flexible piece of wire and attached a q-tip to the end of it and stuck it in my intake manifold, low and behold there is a giant pool of oil in my intake manifold. The only thing that I can think would be causing this is the pcv orifice in the driver's side valve cover so I just ordered a new valve cover with the revised orifice location.

[gish03]

Also for those wondering the truck has almost 118,000 miles. It runs great and youd have no clue it used oil. I hope the new valve cover fixes my problem. I'll try to post some pictures of how much oil I dump out of the intake when I get it disassembled. 

[Jsdirt]

Worth a shot at least.

 

So many problems with modern trucks its hard to remember them all! 

Edited May 15, 2018 by Jsdirt