How often to change oil over 500K?

I bought mine 04 670 with ISX back in 08 with 567k. From day one i changed oil at 15k +/- 1000 with Rotella and from day one im running 1 gal Lucas. Did inframe at 1.4mil Right now 1.6mil. I did tested Delvac and Delo but with Rotella have better oil psi for longer time. I know Prime change oil at 22k and Gordon at 40 or 50k with Donaldson filter setup but didnt wanna do that route so i change mine at 15k
Dont know if you can do same with Volvo engine
Never had good luck with synthetic in my 94 302 build mustang and 07 Tahoe with 5.3 Tahoe will burn 1gal syntheic oil in 2k so i switched bach to regural oil. On the other hand 09 Altima with 2.5 4 banger like synthetic oil and 10k oil changes. I know small car engines are different than big rig engines but thats my .02 cents

 

"synthetic is too slick and thin."
I use 5w40 synthetic it has same viscosity as 15w40 at high temperatures. In cold weather conventional oil will be like gel, synthetic - oil will flow more easy.

"I know soot doesn't suspend well in synthetic and turns abrasive"
That is absolutely nonsense unless you change your oil at extended oil intervals and too much soot becomes sludge at the oil pan.

" Also with engines running hotter 215-218 and hotter oil temps fossil base oil is at a disadvantage until the air temp reaches about 100-105. West Texas Phoenix Las Vegas heat. Then synthetic breaks down fast"
I run a lot of mountains I68, I77. When I tried conventional oil engine start to consume oil after 10000miles. When I put synthetic 5w40 engine consumes oil after 18000miles. So how synthetic oil breaks fast?? From my expierence conventional breaks more faster.

 

So I'm not trying to beat a dead horse but just yesterday had a truck come into the shop. Been using amsoil 5w40 premium synthetic oil at 45 bucks a gallon and he just wanted a plain old valve adjustment done. Truck has 297,348 miles. And had a cam failure. I thought about this and decided to post a picture or two. He went by the amsoil rep recommendation and stretched his oil change interval to 60,000 miles and as a matter of fact was going to go get it changed after the adjustment. Also this is the first time the valve cover had been off since he bought the truck new. So all lash setting were from the factory. I spent a couple hours going over his service records which he actually keeps in the truck, and at least his maintenance records meticulous. The longest span between oil changes was 60017 miles. With his records I decided to get my DSM (Volvo corporate rep for our dealership) involved. The truck only had base warranty 2yr/250k on engine no purchased coverage. He was out by mileage. These are instances that most customers don't see where the dealership goes to corporate and tries to get them to goodwill either parts labor or both or a dollar amount towards the repair. Sometimes we succeed and the whole repair is covered, other times we get parts covered, sometimes they just decline any goodwill. This was one of those times where the rep had to decline due to extended oil drain intervals. As such Volvo states explicitly what oil change intervals are, and if records are kept and within acceptable limits the rep has the ability to goodwill up to 5 years 500k miles. I will say that he requested the can sent to a lab to see if it was lobe coating failure or due to the oil. We took a sample of the oil too. The failed lobe is #3 VEB lobe. Not an injector or valve lobe, a weird failure as I have never seen a single failure on one of those lobes ever. For full disclosure he came in with egr valve flow insufficient codes active (mass flow) root cause was egr cooler plugged with soot no internal coolant leak. I was able to get that repaired at no cost to the customer even though he signed an estimate for the complete repair. The rep did come thru in that instance. The customer was unaware of the goodwill until he came in and paid the bill. I explained to him the why goodwill was decline for the can and he was good with that and had been told previous about the drain intervals so he wasn't surprised by that either. As you can see all damage was to one lobe in 2 seperate spots. There was no damage to the roller but the complete rocker was replaced.

 

it has to be something from the oil that is a very strange way for a cam to go bad i've never seen one like it specially on a veb lobe

 

Is this cam from isx or d13?

 

d13 from what it looks like

 

The synthetic vs. conventional argument always reminds me of Bugs and Daffy...

It's duck season!....no it's wabbit season!

 

D13. Its the exhaust brake lobe. I've seen a lot of can failures but never once seen a VEB lobe look like that, especially under 300k miles

 

the cam journal doesnt look good either,full of small kraters