What Does It Mean to Bulletproof A Diesel Engine?
No, you shouldn’t shoot at it.
There's a term that gets thrown around fairly frequently not just from diesel engine builders, but by automotive enthusiasts from all walks of life: "bulletproof." Simply put, "bulletproof" implies having an unequivocal amount of reliability. Interestingly, while the concept is nothing new, the term didn't really explode in popularity, according to the amount of Google searches anyway, until about mid-2009. Not coincidentally, this was also the same year that BulletProof Diesel, a diesel engine parts manufacturer based in Mesa, Arizona, was founded.
BulletProof Diesel quickly became synonymous with fixing the many flaws found on Ford's 2003-07 6.0L Power Stroke Diesel V-8 engine. Today, the company offers a wide range of products designed to either improve the reliability or extend the life of a diesel engine, while still focusing primarily on the Ford 6.0L, 6.4L, and 6.7L Power Stroke engines.
How To Bulletproof A 6.0L Power Stroke
The basics of "fixing" or "bulletproofing" the Ford 6.0L, which was manufactured for Ford by International, revolve around the oil cooler and exhaust gas recirculation (EGR) systems. In short, the factory stacked plate-type oil cooler easily becomes plugged with gunk from the cooling system. When this happens, it restricts fluid flow to the EGR cooler, which in turn then boils what little fluid is has flowing through and bursts. This burst allows exhaust gasses to enter the coolant system, mimicking a blown head gasket—and sometimes actually causing damage to the gasket as well.
BulletProof Diesel developed a fix for this by replacing the factory oil cooler with an external unit and updating the EGR cooler internals. The company's parts carry CARB EO certification and have been used by law enforcement agencies, ambulance companies, fire departments, and utility companies, along with private owners all across the United States and around the world.
In addition to replacing the oil and EGR coolers, most 6.0L Power Stroke owners also replace the head gaskets either out of necessity or preventatively. They'll also upgrade from the factory head bolts to high-strength studs, and either clean the factory turbo vanes, which can easily become stuck, or replace the turbo with drop-in unit such as the Garrett PowerMax. And, should it tickle your fancy, BulletProof Diesel also offers a billet water pump and upgraded fuel injection control module (FICM) for the 6.0L Power Stroke.
The fine folks at BulletProof Diesel define 6.0L Power Stroke as being "bulletproofed" when it has at least four of the five main problem areas addressed. These five areas are: Oil cooler, EGR cooler, head studs, fuel injection control module (FICM), and water pump.
How Do I Know If My Diesel Engine Is Bulletproof?
Since the term gets thrown around frequently, it can be difficult to tell when an engine is truly "bulletproofed". Speaking of the 6.0L Power Stroke, simply deleting the EGR cooler and adding head studs does not equate to being bulletproofed. In fact, removing any part of the EGR system is a federal crime.
The simplest way to know if a 6.0L Power Stroke has been "bulletproofed" is by getting educated on that things listed above that make an engine "bulletproofed". Does it have an external engine oil cooler? Does it have head studs? Does it have an upgraded EGR cooler, FICM, or water pump? If the answer is yes, then the engine has in fact been "bulletproofed".
Can I Bulletproof Any Diesel Engine?
While Google results would indicate that BulletProof Diesel and the Ford 6.0L Power Stroke are the most frequently searched terms when looking to bulletproof a diesel engine, any engine can see an increase in reliability by installing certain aftermarket parts.
Most frequently, this act of "bulletproofing" comes along with adding horsepower. All engines can benefit from head studs, and when going more extreme, people often choose to upgrade to billet connecting rods and forged pistons. Companies like ARP offer upgraded fasteners for nearly every location, such as main bearing studs, connecting rod bolts, and even manifold bolts. Fuel systems can be made more robust with improved high-pressure pumps and external lift pumps. There are camshafts and crankshafts available, along with flex-plates, flywheels, torque converters, and clutches.
In a nutshell, the answer is yes, any diesel engine—or engine in general—can be made more reliable. What that entails varies wildly based on the manufacturer, power or reliability goals, and also the available budget. What it would take to bulletproof each engine at varying power levels would fill a book—and a rather large book at that.
Now here's the kicker, though. Much like Kleenex has become synonymous with facial tissue, so has the term bulletproof. And in the same sense, if you've not installed parts from BulletProof Diesel, your engine really shouldn't be called bulletproofed; just like calling your Kirkland brand facial tissue a Kleenex isn't technically correct either. However, this topic is one of much debate and one that we'll save for a later date.
What Else Can I Bulletproof?
Using the definition that "bulletproofing" something is to add an unequivocal level of reliability, it can be said that nearly anything can thus be bulletproofed. We see it used frequently in reference to chassis, suspension, and drivetrain parts. The sky really is the limit.