Thor Forums

[frankgtx]

Older MB Sprinter models do not have a DEF gauge. There’s no way to dipstick the DEF level. If you run out of DEF on a Sprinter you will get a warning advising of x number of starts. If you ignore the warnings you will be shut down permanently to avoid damage to the emission control system. Adding DEF once that occurs will not help. You will need to have the vehicle towed or have a MB mechanic reset the emissions control system in order to restart the vehicle. I know the DEF tank capacity. I know the DEF consumption. I maintain a log. Also DEF is basically water and urea. Water evaporates. Urea concentration increases which can cause damage to emissions system. Diesel pick-ups get a lot of use so DEF does not sit in reservoirs for a long time. Motor homes are not driven as regularly. Do not purchase large quantities of DEF ahead of time. Best to keep refilling vehicle reservoir with fresh stuff regularly than letting it sit in hot weather for months (plastic reservoirs with plastic caps are not air tight and evaporation will occur). Note that DEF suppliers do not post date produced info on their containers. Guess why? Also, when you buy DEF the area around the bottle cap maybe covered in white crystals. That is the urea after the water has evaporated. Another great government regulation to make greenies happy. There is a way to disconnect the emissions control system on all diesel/def vehicles. Although Texas does not test emissions for tag renewals on diesels it’s illegal to disengage emissions control. You can be cited if authorities note excessive emissions from your vehicle plus disengaging might create issues if you ever plan on selling your motor home.