How often to change oil over 500K?

If it was a problem with the oil, wouldn't there be damage to other lobes? It's not like different oil was lying the rest of the cam.

Very interested to find out the results from the lab. Please post them when you get a chance.

 

The lab does not show if the oil has thermal breakdown. It just shows metals and anti wear additives. Oil after 20-25k miles breaks that does not show any oil analysis. Many years oil drain intervals were 10-20k, but now most engine manyfacturers stretched to 40-50k miles. Because they like that you will buy rebuild parts for engine or buy another truck. Thry dont like us driving trucks till 1million miles.

 

The lab I was referring to is the one he said he is sending the cam too. Nothing to do with oil analysis. They will test the metal of the cam itself to find out why it broke a chunk out of it.

 

That's clearly NOT wear, it's a metallurgy issue with improper hardness and subsequent chipping. Look at the clearly visible stress cracks too.
Anyway; this isn't a first for Volvo/Mack on these engines as you know....there was a HUGE rash of it a few years ago with this exact issue....and worse in some cases like snapped cams.

Let's also add their cheap valve guide metallurgy issues....Volvo/Mack really need to quit playing the cheap Chinese metal game.

I'm certainly not on board with his drain intervals but let's place the blame where it belongs...another crap Volvo cam.

BTW, was he sampling the oil during his drain intervals? I certainly hope so.

 

Just a quick correction....

Thermal breakdown absolutely does show in oil analysis. It comes in several varieties if you know what you're looking at.
Here's just a few indicators;

1) Oxidation #

2) TBN decrease, it decreases rapidly with extreme thermal stress due to additive package "cook off".

3) Viscosity sgift; VI improvers get "cooked" out of any oil in extreme temps and you will start seeing a viscosity index shift as a result.

Basically in extreme temps all oils will start to cook the additive package out...

However the big difference is synthetic base oils rely far less heavily on the additive package. They have a more natural stability than conventional oil as the additives start going south.

 

All of the base oil arguments are relatively valid, but what many fail to realize is that up to 20% of any motor oil is the additive package that makes it do what it is supposed to do. You have to have the right balance of extreme pressure components like zinc and potassium, anti acid components like calcium, and friction modifier combinations like moly, boron, and titanium. Base oil, conventional or synthetic, is clear like water. The color you see in a fresh sample of oil is the add pack. You can have the best base oil, but with a lousy add pack, you will be repairing a motor in short order. There are some conventional oils that have killer add packs and from a engine life standpoint put some synthetics to shame.

I have long since gotten over the conventional vs synthetic debate. I use a blend. But the add pack of any oil is what I am most concerned with. And to the Delvac 10w30 Elite, from used oil analysis I have seen on other forums, it has a very nice add pack. I use another brand that is similar, so I have no bias. And combing thru a lot of oil samples from others, 10w30 has less propensity to shear out of grade than a 15w40 and 5w40 do.

Now, virtually every multi vis oil has to have viscosity improvers as part of the mix. Synthetics do not need as much as conventional base oils. But while the base oil itself does not really "break down", the viscosity improvers can and do. They can shear under extreme heat and pressure. The oil then goes out of grade. Synthetics, because they need less VI, are less susceptible to shearing. Hence the concept that they hold up better than conventional oils. But it is not necessarily the oil itself so much as it is the viscosity improvers.

While technically, a lab does not show thermal breakdown, per se, it does show the kinematic viscosity at 100C of the oil at the time of the sample, which gives it it's grade classification. That shows if the oil had stayed in grade or is thickening/thinning due to any number of factors like VI shearing, fuel dilution, etc. A typical 15w40 or 5w40 starts out with a kinematic viscosity at 100C of around 14.5. If it is at down to around 12.5 or getting close, it has sheared out of grade and is no longer fit for use.

But that cam example, that is metallurgy. No oil is going to stop bad engineering.

 

Delo400 le is good oil ?

 

Have you found any reason to quit using the interval you have been, or in this case, what the OEM recommends? That is a starting point anyway. Then go from there. I took a N-14 to 1.4 million miles (no major repairs) and just did the same 30,000 mile oil change intervals for all of its time with me. Never felt any reason to do it any different. When in doubt, use the interval the OEM recommends as a starting point and then go up or down on how things work out. There is no hard rule on what interval to use. Some will argue that you need to change frequently, others will say it is a waste. Find out what works for you and helps you sleep at night and go with it.

 

Well, every engine being made today for commercial trucks are factory filled with 10w30. I think it is beyond "recommending" for 2016. They have been factory filling with 10w30 for almost 2 years. That is all the engine OEM's.... Detroit, Cummins, Volvo/Mack, Navistar, Paccar. The main reason that many don't realize that is because they never read the manual or the delivery sheet from the dealer. They just start the truck and drive off... you know... like steering wheel holder would.