Extend Oil Life

John Baxter | April 01, 2012

Arcy also says coolant should not run at too low a temperature. This happens because of a failed thermostat. Cold running causes poor combustion and fuel dilution.

Also keep the oil pan full. “If it’s below the maximum, that accelerates degradation, especially from heat,” Banas says. Keeping the pan full also replenish additives, too.

The heat exchanger under the two turbochargers is the oil cooler. Keeping the cooling system clean prevents scale in the oil cooler, too, and this means the oil stays cooler and can resist oxidation much longer.

One of the most critical areas is dirt ingestion. Banas says, “Don’t remove and replace the air cleaner unnecessarily, as that can cause the seals to deteriorate.” Be careful to check the hose connections on the piping that carries the intake air from the air cleaner housing to the suction side of the turbo. A small amount of dust, which is harder than engine metals, can make short work of an engine’s major parts, says Banas.

Don’t be too lax on filter changes, though. Failing to change the air cleaner at recommended intervals can cause it to “become so clogged that it causes increased stress on the oil,” Arcy says. Engines starving for air create more soot.

Adjusting the overheads at recommended intervals will improve engine breathing and injector performance, thus reducing oil soot, while also reducing wear metals in the oil.

Coolant is another critical item that can leak into the oil. Banas says today’s most common source for such leaks is the EGR cooler, which “can cause slow, continuous contamination.” The antifreeze in the coolant reacts with oil, which then oxidizes and becomes abrasive.

Watch for fuel dilution in oil analysis reports, though it’s not common, Arcy says. “The oil’s detergents can handle normal amounts. But a leaking injector is a big problem. Fuel washes right down the cylinder walls.” Most of these troubles are immediately revealed through oil analysis, he notes.

Proper cooling system maintenance means radiator tubes stay free of scale like this. That means the coolant remains at a lower temperature which, in turn, means cooler oil that better resists oxidation and thermal breakdown, and will last longer.

Good maintenance of the injection system and the overheads will also help in reducing oil stress. “To extend changes you need to be at the top of your maintenance game,” Banas says. “A lot of the best fleets pay quite a bit of attention to valve adjustment intervals.” He has seen high levels of lead resulting from extra stress on related parts if valves go unadjusted. Poor valve adjustments can also affect engine breathing, and generate excess combustion soot. With unit injectors, the performance of the fuel system can be seriously compromised if overhead adjustments are neglected. Also, Consult your engine dealer as to a good interval when injectors should be pulled and serviced, or replaced with factory-rebuilt units.

Arcy says an injector with a bad spray pattern “can cause fuel to wash down the cylinder walls.” In such a case, using an injector-cleaning additive could help. Gambill says, “Ask your fuel vendor to ensure they filter the fuel. This will help keep fuel injectors clean.” Use fuel filters of the recommended micron rating so internal fuel system parts won’t be scored by tiny dirt particles.

If you extend engine oil changes and don’t grease in between them, Gambill says, use a long-life grease like Delo’s ESI. Greasing is significant because proper lubrication of suspension and steering parts will help keep the truck in alignment and save fuel, which means an easier life for the oil.


3 keys to extended intervals

Use good filtration practices

“Use a filter that will meet all the engine manufacturer’s specifications, and always change it at the recommended interval,” says Shell’s Dan Arcy. “We have no issues with either bypass filters or centrifugal designs. Pulling small contaminants out is always an acceptable practice. Note that Detroit Diesel extended the change interval on the DD15, and filtration technology was a big part of what made this practical.”

BP Castrol’s Corey Taylor, senior development technologist, reminds you to always change filters with the lube. He says some operators skip the filter change to save money, believing the clean oil will take care of any problems. He stresses the need for new filters so additional impurities will be removed.

Involve the filter supplier in considerations of extended drains, says ExxonMobil’s Rob Banas, or do your own investigation. “You might need better capacity (for dirt), or better internal construction.” He says many of ExxonMobil’s customers running extended drains with synthetic lubes use filters with synthetic media, and some can run long drains without an intermediate filter change.

OverdriveOnline.com strives to maintain an open forum for reader opinions. Click here to read our comment policy.