In 1998, Dodge phased out the highly acclaimed 12-valve 5.9L Cummins turbo diesel engine in its medium-duty pickup trucks with an upgraded 24-valve version that featured common rail injection and increased power output. Further refinements to the 24-valve 5.9L Cummins further enhanced performance with the higher-performance version, which offered over 100 horsepower at the end of engine operation in 2007. For nearly a decade, the 24-valve K 5.9L Cummins continued. Be the power plant of choice for a generation of diesel-powered Dodge trucks and quickly secure its legacy as one of the best engines Dodge has to offer.
Although generally considered one of the latest bulletproof diesel engines, the Cummins 5.9L 24-valve engine has some common problems that can cause serious problems in the long run. Chief among these problem areas is the holset turbo which can fail, especially on vehicles with high mileage. This usually causes a lack of increasing pressure at the intake, leaving you without power, or in the worst case, if not diagnosed, causing catastrophic engine damage.
The most common point of failure for a factory 5.9L Cummins turbo oil seal. Often times, a worn seal on the center hub rotating assembly allows lubricating oil to enter the inlet as well as the exhaust. Engine oil in the intake can be particularly bad on a diesel because not only can it clog your intercooler, but it can also cause an unexpected increase in engine RPM beyond the throttle input. On the other hand, oil in the exhaust system can damage the oxygen sensor and cause excessive smoke with a bluish tinge in the exhaust pipe. While it’s easy enough to notice the smoky exhaust and oily tailpipe, the oil inside the intake can only be seen by removing the post-turbo charge pipe and induction system. Some oil residue is common within the intake system, but if you find puddles of oil, you are looking for a very bad turbo.
Another type of turbo failure occurs when the bearings within the center hub rotating assembly begin to wear out. As discussed above, this can be due to lack of lubrication due to age and high mileage, or a clogged oil feed line or faulty oil seal. Because a typical turbocharger can spin much faster than its engine can, up to 200,000 RPM, excessively worn bearings can cause the compressor fan to come into contact with the sides of the compressor casing. This will usually create some vibration under the hood and in extreme cases cause metal shavings and parts of the compressor blades to enter the combustion chamber, where they can cause serious damage to the internal parts of the engine.
The earliest warning sign of bearing failure is a loud hiss or hiss during acceleration that increases or decreases with RPM and load. You can also inspect the turbo for high impact play by removing the intake pipe powering the turbo and then moving the compressor fan with your fingers. A small amount of back and forth on the compressor shaft is normal, but any play to the sides or any amount that causes the fan to hit the sides of the casing indicates a bad bearing. The compressor fan should also rotate freely by hand without any resistance. If you encounter any situation, you will have to replace the turbocharger unit.
BuyAutoParts.com stocks the new genuine Holset Turbocharger for the 5.9L Cummins Diesel that can restore the performance lost to your Dodge Ram truck by a malfunctioning or failing turbocharger. These turbos are brand new like any other Holset turbo you can buy from your dealer, but without the dealer prices. We also stock the complete Holset Turbocharger Installation Kit for the 5.9L Cummins Diesel Engine which includes all the gaskets you need to properly connect your new turbo.
We recommend purchasing a Cummins 5.9L Turbo Installation Kit with Oil Feed Line so you can be sure your new turbo is lubricated unrestricted and that your oil system is not contaminated by metal scraping from your old worn out unit. If you have any questions about which turbocharger you need for your 5.9L Cummins diesel engine, please call one of our certified parts specialists at +1-419-404-8015, email us, or visit the site or easy to use live chat feature on . on every page of our site.