* Head gasket failures: This is arguably the most common and costly problem. The head gaskets were prone to failure due to insufficient clamping force and a poor design that didn't adequately handle the high cylinder pressures and temperatures. This often resulted in coolant leaking into the oil (creating milky oil) and vice-versa, leading to catastrophic engine damage.
* High-pressure oil system failures: The high-pressure oil system, responsible for lubricating critical components like the injectors and the turbocharger, suffered from multiple points of failure. Problems included:
* Oil cooler failures: The oil cooler, responsible for cooling the high-pressure oil, was prone to leaks and clogging, leading to restricted oil flow and potentially catastrophic damage.
* High-pressure oil pump failures: The pump itself could fail, starving the engine of oil.
* Injector o-ring failures: Leakage from injector o-rings could lead to low oil pressure.
* Injector problems: The injectors themselves were expensive and prone to failure, often requiring complete replacement. They were sensitive to contaminated fuel, and even minor issues could lead to significant problems.
* EGR cooler failures: The exhaust gas recirculation (EGR) cooler was susceptible to cracking and leaks, allowing coolant to mix with exhaust gases. This could lead to engine damage and potentially hazardous exhaust fumes entering the cab.
* Turbocharger issues: While not as consistently problematic as the other issues, turbocharger failures were not uncommon, often due to lack of lubrication from oil cooler or high-pressure oil pump issues.
* Water pump failures: The water pump, while not unique to the 6.0L, also had a higher than average failure rate, contributing to overheating and other problems.
The cumulative effect of these problems is that the 6.0L Power Stroke often requires significant and expensive repairs. Many owners have invested thousands of dollars in addressing these issues, often multiple times. While some of these issues can be mitigated with proper maintenance and upgrades, the inherent design flaws made this engine a challenging and costly one to own.
