Oil Consumption

[waltman]

Does anyone else have their 6.6 gas engine consuming oil? The last month or so I've been having to top the oil level up, I changed the oil on December 29th and when checked it was slightly over full, today it is halfway down the dipstick with 700 kilometers or about 435 miles of driving. I bought the truck in June of 2022 and it never used a drop of oil until about the beginning of December.  I haven't towed anything since August and don't frequently drive high speed freeways, all oil changes were done on a 7-8,000 kilometer basis or about 5000 miles. Any feedback or knowledge would be appreciated before I see the dealer.

[Another JR]

It’s winter. When you changed it was the engine warm?  When you recently checked it was the engine very cold?  That could account for about a half quart volume change in 8 quarts.  

[waltman]

Yes, that's true. It was cold here yesterday when I checked and the engine was warm when I changed the oil. Thanks, I didn't consider that.

[Pryme]

I changed my oil at 800 miles. Now I have 2,600 and just checked the oil warm. Still at the top of the cross hatches. 

[KARNUT]

Over the years I resist checking oil on trips or different locations. Like gas stations. If I do unless it’s over a qt low ( which is never) I call it good. The last time I forgot my own advice I drove myself crazy worrying about a half a qt low on my stick or more at random filling stations. After 3000 miles once home the next day. It was exactly at the same level when I left. If you see a leak or suspect you’re burning oil still following the over a qt low rule should apply. Otherwise you’ll drive yourself crazy. Pick a spot and use that spot when cold to get an exact measurement. Making sure your level.

[elcamino]

Low-quality oil can cause oil consumption

You may also be using a motor oil with poor heat resistance. Conventional motor oils contain light, unstable molecules that more easily lift out of the solution in the presence of high heat, much like the heat of the sun lifts water molecules out of a puddle. As a result, the oil level drops as the oil is converted to carbon deposits throughout your engine.

[waltman]

I've only used Pennzoil Platinum synthetic from the first oil change. I'll keep a close eye on it and let you guys know what I find out over the next few weeks, thank you all for the replies.

[elcamino]

Here is a link to the oil you chose. Note Volatility is listed at 9.1 

 

http://www.pqiamerica.com/June 2014/pennzplatinum.htm

 

http://www.pqiamerica.com/noack.htm

 

 

 

[waltman]

4 hours ago, elcamino said:

Here is a link to the oil you chose. Note Volatility is listed at 9.1 

 

http://www.pqiamerica.com/June 2014/pennzplatinum.htm

 

http://www.pqiamerica.com/noack.htm

 

 

 

Do you suggest I change brands?, if so what do you suggest? 

[64BAwagon]

I would try checking the oil under the same conditions each time. I typically check mine in the AM before driving it. Once you establish a consistent method of checking it you can see if its actually using oil. Mine has 11k on it and most of that is towing and I have never needed to add a drop. Last fill was with Kirkland 5W30 and before that with Rotella gas truck 

[Jettech1]

On 1/16/2023 at 5:58 PM, 64BAwagon said:

I would try checking the oil under the same conditions each time. I typically check mine in the AM before driving it. Once you establish a consistent method of checking it you can see if its actually using oil. Mine has 11k on it and most of that is towing and I have never needed to add a drop. Last fill was with Kirkland 5W30 and before that with Rotella gas truck 

I've been wanting to try out the Rotella gas truck oil.  I have no consumption issues, just that one issue that drives me nuts that I've posted about before is the oil pump noise during a cold start.  Do you have that noise with the Kirkland or with the Rotella?  I know GM says it's normal.  But I hate it.

Edited January 21, 2023 by Jettech1

[64BAwagon]

I havent had any issue with mine and didnt notice any noises. I also havent had to add a drop of oil in almost 11k miles with most of that towing my fifth wheel. 

 

[Another JR]

I suspect all these trucks have similar oil pump noise on start up. Some people are aware of it, and others aren’t. If you start it in a garage or other enclosure you definitely hear it more. I doubt oil type would make much difference. The system obviously allows an amount of drainback over time that leads to the reprime noise. I doubt you can significantly affect the drainback characteristics with a difference in oil type within the oil specification of the engine. 

[Jettech1]

7 hours ago, Another JR said:

I suspect all these trucks have similar oil pump noise on start up. Some people are aware of it, and others aren’t. If you start it in a garage or other enclosure you definitely hear it more. I doubt oil type would make much difference. The system obviously allows an amount of drainback over time that leads to the reprime noise. I doubt you can significantly affect the drainback characteristics with a difference in oil type within the oil specification of the engine. 

You are probably right.  I was going to try a 5W-40 hdeo oil and I still might.  We will see.  But that noise....ugggg....I hate noises...lol...

[Grumpy Bear]

Sliding vane pumps make noise.