Burning quite a lot of oil.... Help

[Matthew Civatte]

Okay I have an 06 GMC Sierra 2500HD 6.0 Gasser. Here lately for the last few weeks now I have been having to add 4qts of oil within a weeks time. I also have blue smoke upon heavy acceleration and once the truck is warmed up at idle it'll smoke faintly. Recently did a compression test on the passenger side and everything checked out good. Ran out of daylight so I wasn't able to do the driver's side yet. But just curious and wanted to pick y'all's brain about what could be the issue. Valve seals or the rings, I don't think my year model has a changeable PVC valve. Which one would be the best case scenario lol. I'm hoping that the truck can make it until taxes because I'm a single income household so if I can maybe fix the problem myself that would be great. Thanks in advance. 

[Grumpy Bear]

LQ9? 

 

How many miles? Oil in the intake? 

Edited November 28, 2023 by Grumpy Bear

[Matthew Civatte]

27 minutes ago, Grumpy Bear said:

LQ9? 

 

How many miles? Oil in the intake? 

Not 100% sure if its an lq9 or not. Just 2 thousand over 200,000. And yes I do have oil in the intake. Not a lot but pretty noticeable. 

[CamGTP]

A heavy duty truck is an LQ4, the LQ9 was for half tons only and mainly just the denali and escalades.

 

At this point I'd attempt to run some sort of cleaner or additive through the engine to see if it would help clean up the oil burning. Even switching oil brands or running a different weight oil.

 

It's pretty hard to say if it's valve seals or if it's getting most of it past the rings.

[richard wysong]

Maybe either the pcv hose or the breather system in the valve cover containing the pcv is clogged causing the system to work backwards pushing oil into the crankcase breather

[Grumpy Bear]

3 hours ago, Matthew Civatte said:

Not 100% sure if its an lq9 or not. Just 2 thousand over 200,000. And yes I do have oil in the intake. Not a lot but pretty noticeable. 

 

More Information for GM GENUINE 12570427 (rockauto.com)

 

This would be my first move. Think horses first, zebras next, unicorns last. PCV orifice and baffles. That's the horse. Most common cause if it's never been changed. Can't be serviced. 

 

Can you tell us about the oil Maintenace program on this unit? What oil do you use and how often do you change it. Is that routine and fluid consistent?  Own it from new? If not, do you have its maintenance history? And? 

 

If you decide to replace the cover, please take photos of the rocker area and the inside of the valve cover.  

 

 

 

 

 

 

Edited November 29, 2023 by Grumpy Bear
additional content

[Matthew Civatte]

12 hours ago, Grumpy Bear said:

 

More Information for GM GENUINE 12570427 (rockauto.com)

 

This would be my first move. Think horses first, zebras next, unicorns last. PCV orifice and baffles. That's the horse. Most common cause if it's never been changed. Can't be serviced. 

 

Can you tell us about the oil Maintenace program on this unit? What oil do you use and how often do you change it. Is that routine and fluid consistent?  Own it from new? If not, do you have its maintenance history? And? 

 

If you decide to replace the cover, please take photos of the rocker area and the inside of the valve cover.  

 

 

 

 

 

 

I bought it used two years ago and it was regularly maintenance, I did a Carfax check on it and have previous history on it.... Since I owed it I've done my own oil change on it, usually every 5,000 miles but sometimes a little over. I've always used 5w30 oil and what ever oil filter AutoZone gives me. I will definitely pull the hose off of the Pcv and see if that is clogged or something. 

[richard wysong]

it is possible the valve cover itself is clogged as well

[Grumpy Bear]

21 hours ago, richard wysong said:

it is possible the valve cover itself is clogged as well

 

Point I was making.  

 

A gallon a week is allot of oil even if you drive a lot of miles. More than you could force past valve seals. 

 

I asked if the oil was in the manifold. He said yes. Getting past valve seals or rings moving up past the piston can't get to the manifold. So, the PCV system (horses), Stuck rings, (Zebra) or the rings and bore are just flat worn out (Unicorn). 

 

Motor doesn't have a conventional PCV valve so orifice and baffle system. Both part of the valve cover in most designs. He does his own work and has limited resources thus the suggestion. It's also why I asked for his oil maintenance and PICTURES from the valve spring area and underside of the cover. 

 

 

Edited November 30, 2023 by Grumpy Bear

[Matthew Civatte]

I will be digging deeper into this problem over the weekend.... Previously before this problem that I have I did replace the upper intake with a used one out of a junkyard. I replaced it due to the throttle body bolts being over tightened and cracking the intake. Could that have possibly have anything to do with it. I did clean the top and replaced the knock sensors while I there.... It had your typical dirt and grime. If I can find a picture I will upload it.

[Matthew Civatte]

What type of cleaner would y'all recommend before taking anything apart? Marvel's mystery or kreen?

[CamGTP]

Liqui Moly makes a engine flush and a motor oil saver, either of those products to me would be worth a shot.