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Heads up on those new DEF injector designs from the 2022 model year trucks | Diesel Mechanics - Librear

Heads up on those new DEF injector designs from the 2022 model year trucks

We had a fleet of delivery vans come through the shop, all with the same engine. The ones from 2021 were fine, but the 2022 models started showing crystallized DEF clogging the injector tips after only about 15,000 miles. The housing design changed to a smaller, more recessed port that doesn't get as hot. It took us three vans with the same fault code before we spotted the pattern. Now we're telling drivers to run the trucks for a good 20 minutes after a regen cycle to try and burn it off. Has anyone else found a better fix for this, or is it just a bad design we're stuck with?

3 comments

3 Comments

hunt.kevin5mo ago

That thing about running for 20 minutes after a regen is interesting, but I'm not sure it gets hot enough where it matters. The real problem is that recessed port design, it just can't keep the tip clear. I see what @karen_martin is saying about a simple fix, but this feels more like a core design flaw they need to own up to. We've had some luck with a different brand of DEF fluid, the one that says it's for cold weather, but it's just a band-aid. They need to put the heat back into that housing.

victor_lane605mo ago

Man, you're right about it being a design flaw. But has anyone checked if the new housing material itself is part of the problem? I remember @hunt.kevin talking about the port shape, but what if they switched to a cheaper alloy that doesn't spread heat the same way? That would make any fix pointless. They could add all the heat they want, but if the housing soaks it up wrong, the tip still freezes. Makes you wonder if the fix is more than just a little shield, doesn't it?

karen_martin5mo ago

We had a similar thing with some new lawn mower engines a few years back. The exhaust port was redesigned to meet a noise rule, but it just trapped grass clippings and cooked them into a hard carbon cake. The fix was a stupid little metal shield that cost twelve cents to stamp out, but it took them two model years to admit it was needed.