The Detroit Diesel DD15 is known for its power and fuel efficiency, but like any advanced engine, it’s prone to specific issues over time. Whether you manage a fleet or drive a single rig, understanding these common DD15 failures can help you stay ahead of costly repairs and downtime.
Here are the top problems diesel technicians regularly see with DD15 engines — and how to avoid them.
DD15 engines often experience fuel injector issues due to carbon build-up or internal wear. Symptoms include:
Prevention Tip: Stick to a regular fuel system cleaning schedule, use OEM-quality fuel, and replace injectors every 300,000–400,000 km as preventive maintenance
Leaks at the front gear housing (timing cover) or high-pressure fuel pump are common in DD15 engines. Left unchecked, these can lead to oil pressure loss and damage to engine bearings.
Prevention Tip: Regularly inspect seals and replace gaskets early. If you notice oil pooling or burning smells, book a leak diagnostic immediately.
Because DD15 engines are EPA-compliant, they rely heavily on exhaust gas recirculation (EGR) and diesel particulate filters (DPF). Both can clog over time, leading to:
Prevention Tip: Use Detroit-approved oil, complete regens properly, and clean the DPF every 250,000–300,000 km.
If you notice loss of boost, whistling noises, or poor acceleration, your variable geometry turbo (VGT) could be failing — a common issue in older DD15 models.
Prevention Tip: Check for boost leaks regularly, avoid excessive idling, and replace the turbo actuator at regular intervals to extend turbo life.
A clogged crankcase breather filter can result in pressure buildup and lead to oil leaks or gasket failures.
Prevention Tip: Replace the breather filter every 100,000–120,000 km as part of your routine maintenance plan.
At Detroit Diesel Specialists , we’re fully equipped to service and repair DD15, DD13, and DD16 engines. Our certified technicians use advanced diagnostic tools to:
Whether you're managing a Freightliner Cascadia fleet or an owner-operator, we’re here to keep your DD15 engine running strong — with honest estimates, AMVIC-certified service, and a fast turnaround.
Call us at 403-891-9274 | Schedule Online Diagnostics · Repairs · Preventive Maintenance
