Add engine oil!!!

[ShotgunZ71]

16 minutes ago, MORSNO said:

Your occasional towing didn't cause an excessive oil consumption, I'll bet they didn't add the correct amount of oil at your last oil change.  Most V8's are 6 quarts, your engine is 8 quarts and your truck was shorted 2 quarts.

 

 

This is very likely a plausible explanation. Heard of it many times in recent years with engine config changes or different engines than usual. Many places/techs get accustomed to Make/Model takes "x" quarts, so it becomes habit and sometimes they don't look it up to be sure. Could have thought it was the regular 6.0 gasser, put in 6 qts and was done. Never realized the new gasser was a 6.6L and took 8 qts.

 

I'd make sure it got 8 next time and keep an eye on it to be sure.

[Black02Silverado]

Also. you have to wait a good 20 minutes after shut down to check the level.  Seems weird but at least on my 6.2.  I checked it about 2 minutes after shutting it off and it was at the add mark.  I then waited until the next morning and it was at the full mark.

[CamGTP]

Side note, that is some pretty low fuel mileage for that many miles driven lol. Towing surely does that though, or maybe he drives really fast.

[Grumpy Bear]

36 minutes ago, CamGTP said:

Side note, that is some pretty low fuel mileage for that many miles driven lol. Towing surely does that though, or maybe he drives really fast.

8 mpg!!

[Another JR]

Regarding oil change interval discussed above, it’s a good idea to do some research to understand the intake coking issues that some fear will be caused by the direct injection system eliminating fuel washing of the intake areas of the cylinder heads, and the resultant potential for oil deposits to form from the crankcase ventilation system introducing oil vapor and oil condensation in those areas. Other direct injection engines have had problems from that. Part of your defense against that is the additive set in the Dexos approved oils. Those additives break down over time, and you should consider that in deciding on your oil change interval. See the threads on direct injection and on catch cans for discussions of the coking issue.  
 

 

[Ray Pickle]

Where all 5k of miles using 700 gallons towing? If so , that indicates about 7.8 mpg! Thats seems to indicate some pretty aggressive/high speed towing habits for that weight or a high % of hilly terrain. If there is any non towing miles in that figure it is more perplexing. High rpm high speed towing will probably burn a little oil and may be normal. If that is not the case I would be concern about the relatively poor mileage and oil consumption. 

[Truston Gunter]

On 12/15/2021 at 3:55 PM, customboss said:

Fuels dilute of the engine oil is THE player for engine oil usage if all else is normal. 

 

Use a higher quality  oil, change out the air filter more often if you are dusty down there in Corpus. 

 

If you want to KNOW why,  take a oil sample using a good quality lab with GC fuels and FTIR  testing you'll know for sure whats going on.  

 

If you have never changed the air filter on that 6.6 yet that may be allowing too much fuels dilute of the oil by restricting air flow. ECM can only go so far to correct. 

 

 

I use mobile 1 5w-30 full syn. I always thought this was a good high quality oil. It sure is expensive enough! As far as the air filter, at 7K I installed a K&N intake. mainly cause I like the sound, I don't put much stock in HP gains. Would this have an effect by allowing too much air?

[Truston Gunter]

On 12/15/2021 at 4:55 PM, MORSNO said:

Your occasional towing didn't cause an excessive oil consumption, I'll bet they didn't add the correct amount of oil at your last oil change.  Most V8's are 6 quarts, your engine is 8 quarts and your truck was shorted 2 quarts.

 

I do my own maintenance so I can guarantee it had 8 qts. Even my 2015 5.3L took 8 qts so this is not a mistake I would have made but thanks for the input. I sincerely appreciate everyone taking the time to give me your thoughts.  

[customboss]

7 minutes ago, Truston Gunter said:

I use mobile 1 5w-30 full syn. I always thought this was a good high quality oil. It sure is expensive enough! As far as the air filter, at 7K I installed a K&N intake. mainly cause I like the sound, I don't put much stock in HP gains. Would this have an effect by allowing too much air?

Too much intake air flow not an issue, nor is Mobil 1 5w30.  What happens with K&N oiled air filter media is it loads and restricts airflow. That forces ECM to try to counter the restricted airflow. Another issue I have seen in testing is that oiled air filter media if not serviced perfectly can allow dirt ingress in micro tears of the cotton media.  You may be over-fueling needlessly because of that intake system unless its in perfect condition and serviced frequently. 

Edited December 27, 2021 by customboss
oiled not oil

[Truston Gunter]

On 12/18/2021 at 11:24 AM, Ray Pickle said:

Where all 5k of miles using 700 gallons towing? If so , that indicates about 7.8 mpg! Thats seems to indicate some pretty aggressive/high speed towing habits for that weight or a high % of hilly terrain. If there is any non towing miles in that figure it is more perplexing. High rpm high speed towing will probably burn a little oil and may be normal. If that is not the case I would be concern about the relatively poor mileage and oil consumption. 

I don't consider myself to be towing "aggressively" but I do travel at the posted speed limits when applicable. Here in TX alot of the highway speed is 75mph. When I set the cruise control, I get a lot of shifting when going over small overpasses so I tend to lock out the 2 overdrive gears which leave me at around 3k rpms. I figured that puts me closer to the powerband and with a gas engine I didn't think this would hurt anything. Thus my mileage can be pretty crappy. 

[Truston Gunter]

On 12/15/2021 at 3:38 PM, Grumpy Bear said:

Something didn't sound right. A quart in 100 gallons is .25% Sounds like they have a reasonable target for the application.

 

If you use a 2 quarts in 750 gallons that is only 0.07% Not much more than a modern passenger car. (I used the wrong units earlier) towing will make this number higher

 

Sorry I was still on my first cuppa coffee  

 

I've always used .03% to .05% per gallon of fuel as normal. Way I was taught.

 

https://www.ms-motorservice.com/en/technipedia/post/when-is-an-engine-consuming-too-much-oil/

 

[quote] Workshop manuals and operating instructions often provide information on the maximum permitted oil consumption for the engine. If the manufacturer's specification is not available, max. 0.25 to 0.3 % for utility vehicles and up to 0.5 % oil consumption for buses can be assumed.

Oil consumption in modern passenger car engines is usually less than 0.05 %; the maximum permissible oil consumption stands at 0.5 % (all percentage values relate to actual fuel consumption). [end quote]

 

GM in the light trucks and cars will not warranty work until consumption is a quart in 2,000 miles. In the case of a vehicle that is getting 25 mpg that is 1.2% or 240% of the industry maximum standard and 2400% over what most people experience normally. The fact they have this in writing at .25% is not normal for this company and even generous. 

 

Sounds like you don't have an issue...

 

 

 

 

Great info!!! This puts my mind at ease and I appreciate you taking the time to explain it. 

[customboss]

1 minute ago, Truston Gunter said:

I don't consider myself to be towing "aggressively" but I do travel at the posted speed limits when applicable. Here in TX alot of the highway speed is 75mph. When I set the cruise control, I get a lot of shifting when going over small overpasses so I tend to lock out the 2 overdrive gears which leave me at around 3k rpms. I figured that puts me closer to the powerband and with a gas engine I didn't think this would hurt anything. Thus my mileage can be pretty crappy. 

Agreed south texas not a demanding environment for engines or towing unless its really hot outside. 

[KARNUT]

17 minutes ago, customboss said:

Too much intake air flow not an issue, nor is Mobil 1 5w30.  What happens with K&N oiled air filter media is it loads and restricts airflow. That forces ECM to try to counter the restricted airflow. Another issue I have seen in testing is that oiled air filter media if not serviced perfectly can allow dirt ingress in micro tears of the cotton media.  You may be over-fueling needlessly because of that intake system unless its in perfect condition and serviced frequently. 

Most of the oil bath K&N and Amsoil filters I used in my 1/2 tons or pulling rigs had flow indicators. I never had a problem. Of course it’s probably been 10 years since the last one. With the exception of my 383 blown 92 Chevy with 12LBs of boost. That I had for 12 years. I guess that’s just another reason you wouldn’t see my in a newer truck. There’re just too sensitive. 

[Truston Gunter]

On 12/15/2021 at 6:06 PM, Another JR said:

Regarding oil change interval discussed above, it’s a good idea to do some research to understand the intake coking issues that some fear will be caused by the direct injection system eliminating fuel washing of the intake areas of the cylinder heads, and the resultant potential for oil deposits to form from the crankcase ventilation system introducing oil vapor and oil condensation in those areas. Other direct injection engines have had problems from that. Part of your defense against that is the additive set in the Dexos approved oils. Those additives break down over time, and you should consider that in deciding on your oil change interval. See the threads on direct injection and on catch cans for discussions of the coking issue.  
 

 

This is very new to me so I will be doing lots of reading!!!

[Supreme Pizza]

Direct injections engines definitely have carbon issues on the intake valves. I have seen it on other brands. If it were me, I would use a catch-can or maybe even 2 of them, to reduce the likelihood of the carbon issue.