What Are the Most Common 5.9L Cummins Problems?

The 5.9L Cummins diesel engine is dependable and powerful, and it has powered Dodge Ram trucks for decades. Many diesel truck enthusiasts swear by this engine, considering it the best in its class. Of course, nothing is perfect. Despite its excellence, this powerhouse has displayed several quirks. Fortunately, knowing what problems might pop up in a 5.9L Cummins engine could save you money and headaches. You may be able to prevent them altogether! Read on to explore the most common 5.9L Cummins problems.

Fuel Pump Failures

The lift pump and injection pump in 5.9 Cummins crate engines can experience issues. All fuel pumps experience wear and tear, especially when they regularly come in contact with low-quality fuel. It can lead to low fuel pressure, which may cause injector or pump failure.

Here’s a suggestion: install a high-quality lift pump to maintain adequate fuel pressure and prolong the lifespan of your injection system. Go easy on it!

Exhaust Manifold Cracking

High engine temperatures and metal fatigue may lead to cracking in the 5.9 Cummins’s exhaust manifold. This problem may result in decreased performance and potential boost leaks. Try replacing the current one with a high-performance, heat-resistant aftermarket exhaust manifold.

Head Gasket Failures

Many 5.9 Cummins crate engines have head gasket issues, especially after modifications. High boost levels and improper tuning may lead to head gasket failure when pushing the engine beyond its limits. Coolant leaks and continuous overheating indicate a blown head gasket, so watch for them in your 5.9 Cummins engine.

Try employing ARP head studs for added clamping force if you plan to boost your truck’s horsepower and levels. It’s best to work with a professional mechanic to address gasket issues. Generally, talk to your mechanic about any changes you want to make to your vehicle before doing so.

Turbocharger Issues

Revisit your turbocharger. The factory-installed turbo connected to your 5.9L Cummins is reliable, but turbochargers eventually wear out—especially with heavy use. Pay attention to noisiness, oil leaks, and diminished performance that signify your turbocharger is on its way out. Install a high-performance turbocharger, and do regular oil changes. Frequent maintenance will help the new turbo work better.

Thinking of investing in a 5.9 Cummins crate engine? Just be aware of the most common 5.9L Cummins problems as you shop around. Contact us for more information or a consultation on how you can make your truck run better!