GL4

[bossboy2]

(08-24-2019 )Rawze Wrote:  I have never seen elevated copper based on adding a gear lube .. only lower levels.

If you have higher levels of copper than normal, it is almost always an indication of moisture, coolant, fuel, excess soot, or other contaminants getting into the engine somewhere.

It can also be simply that you are showing copper on your overhead cams (very common after 500+k miles) combined with lower then normal oil pressures in the top-end due to excess wear, soot buildup, or other factors like valves adjusted incorrectly.

Also, summer time vs winter can cause differences in wear metals, or if load (heavier weights to haul at certain times of year, etc.) application changes happen. Wear metals usually go up/change slightly as oil gets worked harder, etc.

If you are really unsure about what you are doing and its effects, and you want to play it as safe as possible --> Then stick to manufacturer guidelines and --- simply don't use 10% mix of gear oil in your engine!. I use it in my own engine, and several others on here do as well with high success, .. I can see the difference and clear benefits for my own engine, but it may not be for everyone. Applications and use of the equipment may vary greatly for one truck to another, and this may throw that balance off.

For example: I don't live in northern-Canada and don't have to worry about my oil getting too thick for the pump to handle,.. for someone else... that might not be the case. If I did then I would have been using a full synthetic to prevent it.

Rawze, thanks for the reply. Now that you wrote that, a couple of things now come to mind.

1. I had the rods and mains replaced, oil pump, oil pump housing, and o-rings about 40,000 miles ago as they were already in changing my oil pump o-rings anyway. Could be a possibility that they are still breaking in?

2. There are no other contaminants that are elevated per se except potassium is up a tad but the response from Blackstone is that there is no water, coolant, or fuel in the oil.

3. I had to do some maintenance on the truck...changed fuel pump, air compressor, starter, and the oil filter housing and while that was out I had them change my thermostat also. All at right around 750k.

Although one of these, or a combination of them could be the culprit, I've changed the oil three times since then and I would think these contaminants would have cleared out by now as I changed oil at 12k miles twice and this last time was at 10k miles. BTW, oil pressure is holding like it was a brand new truck. One more thing, for what it's worth, these contaminants showed up after the bottom end and o-pump work was done. At first I thought maybe some coolant spilled into the oil when the oil filter "housing" o-rings were changed but again, I would've thought it should be clean by now. As far as soot is concerned, Mr. "H" took care of that about 1-1/2 years ago and my dipstick still looked golden after 10k miles. Now not so much but it's not dark by any stretch. This is a DD13 Detroit. Next oil change I'll be going back to straight T4 and see if she doesn't clear up. In the meantime I'd like to get it somewhere to get the overhead done, and done correctly. Isn't there a guy over near the truck stops? Georgia RV or something like that?