# Detroit DD15: Common Failures & What to Check Before Buying | Big Rig Risk

> Detroit DD15 risk check: EGR cooler cracking and turbo cartridge seal failures with a verified $400 repair and mileage data before you buy.

**Verdict:** inspect

Recurring EGR cooler cracking and turbo cartridge seal failures show up on DD15s past 700k miles, with one verified $400 coolant reservoir fix — inspect the EGR/turbo/coolant history before buying.

**Documented failure risks:**
- EGR cooler and EGR valve: "I am needing some guidance on this reoccurring issue that I keep having. 2016 Freightliner Cascadia DD15 DT12 Automatic transmission 697k miles... I am having a very weird problem where my EGR valve and cooler keeps cracking. I changed both out in May 2022 because of a crack and now 8 months later I am having to change the same parts because of a crack. Cracks are appearing in the same position."
- EGR valve / coolant system pressurization: "2013 Cascadia DD15... 720k miles. It looks like a pressure buildup in the cooling system. From the moment I start it up there is a lot coolant rushing in from the egr valve into the reservoir. With the old radiator cap on, coolant will gradually overflow the tank and leak out the top."
- Turbocharger cartridge seal / cylinder liner: "2012 DD15 800k miles. Truck ran fine until 797k miles, then DPF problems began causing the Filters to be blocked or clogged... intake side and turbo side CAC pipes have oil in them and a good amount." Diagnosis: "Turbo cartridge seal leaking oil into intake. CAC saturated with oil internal causing 2631/1 code." Outcome: "Cyl 3 cracked liner and blown Turbo. Sold it for 7k."

## Sources
- [thetruckersreport.com](https://www.thetruckersreport.com/truckingindustryforum/posts/12315786/) (accessed 2026-09-14)
- [thetruckersreport.com](https://www.thetruckersreport.com/truckingindustryforum/posts/11747984/) (accessed 2026-09-14)
- [thetruckersreport.com](https://www.thetruckersreport.com/truckingindustryforum/posts/10473263/) (accessed 2026-09-14)

_Last verified 2026-09-14. Source: Big Rig Risk — https://bigrigrisk.com/trucks/detroit-dd15/ — every claim checked against a primary source before publication (see /methodology/)._