How many DEF failures?

[DADSDOGHOUSE]

I have heard about the DEF sensor failures here, Today on Hwy 40 in Utah I saw a Dutch Star parked on side of the road. I was going other way on divided freeway, unable to turn around due to barriers, plus no tools or expertise. I hope he was just taking a break, but could not but wonder if was another DEF head failure. I am hesitant to look at a newer Spartan or Freightliner chassis motorhome that is newer than about 2017 or so. Anybody been able to gather warning signs to watch for if looking at one of these Newmars?

[SteveR]

Not to pop your bubble but DEF issues are only one problem with these coaches. Anything in the Cummins exhaust system is prone to failure and derating. We have had 2 PDM issues in a year. The first one caused a derate because the pollution control system thought we had no DEF...the tank was full so it derated the coach. The second one was just the DS turn signals. But, we also had a NOx sensor failure that would have derated the coach. There are a lot of sensors in the pollution control systems that can go our and derate the coach.



We have a diesel car and it derated on the freeway with no place to get off the freeway. It was great fun driving 10 mph in a 70mph zone in a major city. The whole system is unsafe.



The DEF head is only one of the many issues that can shut the engine down. It is a crazy system.

[outlawten5]

Are pre-2016 less prone to DEF failures?

[racer0624]

outlawten5,
We have a 2015 London Aire and I've been reading everything I can find on head failures. Unless I've missed something the problem started in 2016.

[JMcG]

I have a 2016 Ventana 3725 with 45K miles on it, and so far no problems at all with the DEF head. May fall apart tomorrow but so far so good.
JMcG
2016 VTDP 3725

[FLYING BUTCH]

Just got a non def related service done at Cummins shop. Manager told me mostly Spartan chassis 2016 up to 2019 were main problem coaches.


Safe travels all