Viscosity selection for engine burning oil.

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Vehicle is a 2006 Extended Chevy Express 3500 with 6.0L. I'm currently running castrol edge 5w30. It consumes oil at about 1 qt. Per 1000 miles. I'm going to switch to castrol edge high mileage for the next oil change. I bought the 5w30 but then heard oil with closer viscosity numbers say 10w30 have less modifiers and generally will consume less. The guy at the auto parts store also suggested running Lucas oil oil stabilizer. it just seems to thicken the oil. So with that why wouldn't I just run heavier oil altogether such as 10w40. Is there any truth to any of this? It would be cool if all my vehicles ran the same oil. Just put rotella T 15w40 in the van and my race bike lol.
 
Could be something simple like the PVC system causing the oil burning. Eventually it will do in you converter. Probably more quickly with Lucas goop in the oil.
 
Your oil consumption is not really a problem. Since you understand the idea of running a thicker oil try it out but skip the additives.

The problem with additives is that although they amount to only a small percentage of the total volume you don't know what spec's they meet or if their only function is to lighten your pocket book and make the oil thicker.

Remember to check the PCV and make sure your up to date on service. Write down you observations and see if that helps to track what's happening. If you have a life outside of engine oil it's easy to forget exact dates, mileage and amounts. And let us know how it all turns out.
 
Matt,

First off, DO NOT use Lucas Oil Stabilizer. Period!

Furthermore, these engines do not use oil to this degree without one (or both) issues present; PCV system is clogged, or mechanical damage.

What's your current oil pressure when up to operating temp/hot? Around 40 PSI at 2,000 RPMS, and 25 PSI or so at idle?

(I should copy and save the following as I'm addressing it here on a seemingly weekly basis for these LS engines)...

1. Buy one quart of Kreen. http://www.kanolabs.com/engCle.html

Half a can in your gas tank, half a can in the engine oil. This will not only clean the engine, but will clean the integrated PCV as well. It will also eliminate the lifter tick you're complaining about. Run for 1,000 miles, then drain.

2. Fill with whatever dexos1 5w30 you want. MaxLife 5w30 in 5qt. jugs at Walmart is very cheap ($17), and will help to aleviate the leaks you've mentioned (pan/valve cover).

3. Report back with oil consumption. From here, we'll make adjustments as needed.
 
I'm surprised. I also have a 2006 6.0l that burns the least oil of any vehicle I've ever owned. I recently took the intake manifold off to fix the knock sensors. Its a pretty easy job. At that time I gave the piston tops and rings a blast of carb cleaner right down into the cylinder. That seemed to help, I went from 1/2 qt per 7k to nothing noticeable on the dipstick. So rather than starve the engine with thicker oil I would take a shot and try to clean the rings with a solvent. Its worth it to have a peek at your knock sensors and replace the intake manifold gasket in the process. Videos on youtube take you through it. Pretty simple job
 
Originally Posted By: Goofball1205
Oil pressure is about 30 psi at idle and a little over 45 at 2000rpm.


I'd be willing to bet that your PCV system is clogged (which is also causing leakage you mentioned) -- it would be best if you'd replace a valve cover (one with the integrated PCV). $100 for the new OEM GM part.

Regardless, Kreen and MaxLife 5w30 are still the course of action.
 
Originally Posted By: Ramblejam
Originally Posted By: Goofball1205
Oil pressure is about 30 psi at idle and a little over 45 at 2000rpm.


I'd be willing to bet that your PCV system is clogged (which is also causing leakage you mentioned) -- it would be best if you'd replace a valve cover (one with the integrated PCV). $100 for the new OEM GM part.

Regardless, Kreen and MaxLife 5w30 are still the course of action.


I thought there was no PCV valve, just a "fixed orifice" which does not fail in our 06's
 
Originally Posted By: LeakySeals
I thought there was no PCV valve, just a "fixed orifice" which does not fail in our 06's

First LS engines started with a traditional, replaceable check-valve. Then, they went to a fixed-orifice, replaceable valve. Next they eliminated the replaceable valve all together, and went with a PCV that's integrated into the valve cover.

GM part #12570427 is their latest revision on that, and it works well in permanently resolving the issue.
 
Originally Posted By: Merkava_4
The engine needs 10W-40.

GM has prohibited 10w-40 for decades. My dictionary must have a different definition for "needs" than yours does.
wink.gif
 
why prohibit 10-40 when its cheap to buy and easy to obtain? its the most common oil around here.
 
Originally Posted By: slybunda
why prohibit 10-40 when its cheap to buy and easy to obtain? its the most common oil around here.

It's a bit of a historical thing for GM, when 10w-40 grades were rather poor. Even current 10w-40 grades aren't what you're used to. You're not seeing a bunch of A3/B4 10w-40 options here. Back in the day, you were seeing low HTHS, high VII content 10w-40 options. Most of what you see here for 10w-40 options are simple SN. For me, if I were looking for a cheap 40 grade conventional, I'd go for (and generally did) a 15w40, which at least is going to be meeting something more robust than ordinary API SN.
 
Originally Posted By: slybunda
why prohibit 10-40 when its cheap to buy and easy to obtain? its the most common oil around here.


Because americans got screwed with cheap VII some decades ago, which were prone to shear. So early american 10w-40 had ridiculously low HTHS, which could hurt bearings on engines designed for 15w40 and straight 40.


On the continent, just like in the UK, 10w-40 have been the de-facto standard oil for nearly any engine build from the the 80s until the end of the 90s. Yes, even for GM engines.
Good to have the ACEA. Even the long obsolete ACEA A2/B2 had HTHS >3.5...
(There were also issues with early VII in Europe: in the 80s, sludge became a big problem temporarily.)
 
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Most here don't need 40 and could not care less ...
BITOG does not represent the masses ...
 
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Ok valve cover and kreen have been ordered. I jumped the gun and purchased some 10W30 castrol edge high mileage. Should I take it back and buy the 5w30? Also can I add the kreen in with my current oil and run for 1000 miles then change (it has some Lucas oil stabilizer in with it). Or should I add it with a fresh oil change to start the 1000 miles? Thanks for all the help. This forum is a wealth of knowledge and everyone seems extremely helpful.
 
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