Turbo Failure on your 6.7L Cummins? Here’s what you need to know.
Your 6.7L Cummins turbo is having problems. These are the main specifics.
The 6.7L Cummins engine was originally used in the Dodge Ram Heavy Duty Pickups. This Cummins was the first in the pickup line to utilize a variable geometry turbocharger (VGT). An integrated exhaust brake, less turbo lag while accelerating from a standstill, and unrestricted load demand adjustment while driving are just a few advantages of a VGT turbo. However, the drawback of this turbo is the regular failures it encounters. We get a ton of calls about Cummins VGT failure, and the exhaust brake will generally cease working suddenly as the first symptom.
How it works
There are diesel pickups with VGT available, and although each manufacturer regulates their turbocharger differently, the common feature is to adjust the size of the exhaust housing, which in turn regulates how much exhaust pressure is necessary to turn the turbine wheel of the turbocharger.
Think of it like a yard hose that only shoots water a short distance when the tap is fully opened. To make the hose shoot in a half-circle around your lawn, place your finger over the end of it. The force generated by increasing the opening's size is much bigger even if the amount of water leaving is the same. Even while this is probably not how engineers would define a VGT, you get the idea.
You would find a steel ring attached to several fins, or vanes as they are known in the automobile industry, if you disassembled the Cummins Variable Geometry Turbo. The pressure between your engine and your turbo increases or decreases as the vanes inside the housing move more or farther away from the turbine wheel as the steel ring rotates. The turbocharger's electronic actuator, which is managed by the computer system of your engine's computer, moves this steel ring. When you accelerate away from a stoplight, the vanes are pressed firmly against the wheel, pushing all of the exhaust pressure to turn the exhaust turbine. At a given speed, the actuator moves the vanes away from the wheel, allowing some gas to pass through the turbine naturally rather than being compelled to do so. The boost develops more quickly and vigorously as a result of the pressure increase. Throughout your drive, your ECM continuously checks your exhaust pressure and adjusts the turbocharger's vanes to maintain it within limits. Actually, this is how the integrated exhaust brake of the Cummins engine works. When the throttle is withdrawn, the turbo generates a lot of pressure to hold you back while you decelerate because the vanes move as close as they can to the turbine wheel.
What stalls?
While the aforementioned characteristics are all excellent, the system has many complex moving pieces that must operate together for it to function properly. In most cases, the actuator on a Cummins engine malfunctions and can no longer communicate with the computer, or the steel ring inside the turbo becomes blocked. As a result, the Cummins may encounter a number of issues, but the exhaust brake issue is the most typical one we receive from clients. Either their exhaust brake will abruptly cease working or it will keep working even as they speed up.
It can be devastating for your engine because you're essentially pushing all of your available pressure at the turbo, and if it's jammed shut, this will result in incredibly high pressure spikes between the engine and the turbo. This may soon lead to a blown head gasket since all of that pressure needs to be released.
Can I fix it?
In order to clean the steel ring and housing, people frequently want to remove the turbo, disassemble it, and do so. Undoubtedly, this can be beneficial, but it rarely offers a long-term fix. This can buy you some time, but do you really want to hire someone to take out a turbo, only to have to take it out again to install a new turbo two or three months later? If you're doing it yourself in your garage at home and have the time, it's worth a shot, but hiring a company to do it might get pricey, especially if there's no guarantee that the issue will be resolved.
How much would doing this cost?
The painful phase is about to start! Despite the fact that these turbochargers offer many wonderful benefits, they are not inexpensive. Depending on where you purchase it, you should budget about $2700 CAD for a brand-new stock replacement turbo alone, plus an additional 6 hours of labor for installation.
Spending that much money on a stock replacement seems excessive. A new turbocharger is not infallible, even though the actuators have been improved and are now operating more effectively. These have also been demonstrated to be unsuccessful. Thankfully, a few companies have created a large selection of turbochargers that can quickly replace the stock VGT.
Which do you choose? That perhaps depends on a few distinct factors.
