So I checked my oil 1000 miles after oil change. I didn't check it after I drove away so it's possible they put 5quarts instead of 6. not 100%positive one way or the other. Looks to be about a quart low. My truck is a 2003 GMC SIERRA with a 5.3. Got the truck with 23k and now has 115k. I have used Royal Purple 10w30 every 5k miles. Is this a problem anyone else has had? thanks guys.

 

First of all I've been told by several mechanocs no matter wut oil always change oil every 3k. Secondly the oil is most likely being sucked into the intake manifold. Do u ever notice it blowin smoke on startup?

 

hell no, never noticed it doing that at all. I have had no indication of this at all. It's full synthetic so why every 3k, and also the computer engine oil life goes way beyond 3k miles as well. Not saying either of those matter, but I've been told royal purple is good to 6k, I still changed it at 5k. Everytime I change my engine oil life still reads more then 10%. I have been told that it's okay to go by both of them so I always have. Should I just start changing it every 3k? or do I need to do something more to not cause damage? Thanks again.

 

my oil is about a quart low after 3k miles as well and use RP 10w30 but then again, i always put in 5 quarts anyway.
i'm trying some bar's leaks rear main seal repair and that seems to have helped my truck retain more oil.

 

Synthetic oil runs cooler than non at operating temp. Pull ur valve coves and see if ur rockers look all gummy. That's what mine looke like when I ran RP for 5k so. Asked some mechanics and they told m to change every 3k no matter what and since I have she still clean

 

a buddy of mine runs amsoil 30k miles with a filter change every 15k (no that's not a typo) on his work truck and it has 285,000 miles on it. i think his is a 03 2500HD w/ 6.0. everyone's opinion is different. i for one change my oil every 5k miles. i think scott changes his every 6-8. bill doesn't even keep up with his... he just changes it when it looks like it needs to be changed.

 

thanks again guys, i've also been told i need to change PCV and also that these motors drink down the royal purple. I'm going to do my own oil change this time and watch what happens, as well as pull valve covers.

 

It has to be an error of adding only 5 qts and not the required 6 qts. I bought my truck in 2006 with 64k on the clock. I ran RP 5w30 till 180k changing the filter and adding a quart every 3k and doing a full change at around 10k-12k and had NO problems. My truck currently runs AmsOil 0w30 signature and the Amsoil oil filter and have 216k on it now with NO smoke what so ever. At 5k miles my engine burns off about 1/2 a quart. You can defninatly run synthetics longer than conventional. If your curious about how long you can run your synthetics just check out the manufacturs website and they can get more detailed than the back of the bottles. I have always taken the recomended change intevals and reduced them by 3k-5k just as an added safty factor for my personal satisfaction.

 

I love Amsoil. Its really expensive (little over $100 every full change) but the extended oil life is insane with this stuff. At 5k miles my oil still has a golden brown color. I change mine around 15k-17.5k miles just when I feel like changing it. Amsoil says I can run it out to 25k oil and filter change but Im pretty hard on my truck and dont mind changing it early.

So your truck isn't burning any oil at all. If you only fill to 5 quarts and need 6 quarts and at 3k miles your showing only one quart low your doing fine but need to add that 6th quart. No need for oil additives.

 

glad to hear i'm not burning any. i do have a slight leak at the rear main seal but i'm trying to fix that.