DEF Tank SCR 2011 Fleetwood Tioga Ranger 24L MB Sprinter

Your DEF tank is plastic - no matter what color it looks. DEF is clear but if you let it dry out, you will get a ton of white crystals (which are urea). Check your documentation but DEF tank volumes are 6 to 12 gallons. You can use the weight of water (8 lbs/gal) if you are concerned about weight. I would not worry about weight - you don't worry about the weight of 13 qts of oil in the engine do you? A full tank with the V^ diesel is good for 6-8000 miles so keep a jug and top it off before a long trip.

Since you are unfamiliar with diesels, here goes:
1. Diesels ignite the fuel air mixture with compression. They do use fuel injection to inject fuel at the precise time to ignite it. Fuel filters need to be kept clean and fuel quality is very important.

2. Like all internal combustion engines, diesels have pollution control systems. Similar to cars but very specific to diesels. First up is the DPF or diesel particulate filter. This catches the soot produced by combustion (diesel fuel is not as highly refined as gasoline) which is a major component of air pollution generated by diesels. The DPF is monitored by the engine computer and when it is dirty enough, it is regenerated by burning a big load of diesel fuel in it.

3. The second major pollutant of diesel engines is NOx or nitrogen oxides. Two systems are used to control this - the EGR exhaust gas recirculation valve, and SCR or selective catalytic converter. The SCR is the component that uses DEF (diesel exhaust fluid) to react the exhaust with a special catalyst that converts NOx to nitrogen and water.

Diesels don't require much maintenance - clean fuel, clean air filters, oil changes once every 15,000 miles or so, DEF, other than those few things, enjoy driving it. One other thing - do not idle it for long periods of time. It won't warm up and you will plug up your DPF.

wow thanks! does that mean that the white crystals "weeping" from the tank lid are bad? or of concern? someone let it dry out?

rv4jimnme - you do not want those crystals hanging around. Basically, the crystals are corrosive. You should was the area down with water and make sure all the crystals are gone, otherwise you are going to have a real issue later on. Statement on the DEF bottle says to remove any spilled or overage of liquid.

well I just bought this from a dealer and the tank was recently painted very shiny do you think this was a problem before? or just maybe the cap is loose. thanks so much for your help
Marlene

Welcome Marlene...

LuvLabs has given good advice. I'd add a couple points. DEF fluid is DEF fluid. It all meets ISO 22241 standard. A Crows opine, is that you want to keep the cap and fill port surgically clean to avoid the "white creep". Same with the fill bottle...kitchen counter clean. If you use a funnel, get one only for DEF. Keep it clean and in a zip lock bag.

DEF evaporates leaving that creepy white crystal film on everything. That may not be healthy for your DEF system if if it gets inside the tank.

Opinions vary as to filling the tank. Some say use the "school solution" and wait for the Lo DEF light. Others favor refilling from time to time. This latter group seems to be growing. I'm in the latter group.

Just as crystals form on the outside of the neck and cap, I think it will do the same on inside parts of the tank when they are not wetted and "dry" out. So better to top it off from time to time to keep everything wet. Especially since it is an RV and not driven regularly.

Dear Mr. Old Crow,

I am sorry to be so dense. The Tech is here and has brought a new cap with a seal for the top part of tank. So I imagine that will stop the fluid from seeping out the top. However, I am wondering if this letting the lite come on warning thing and the fluid being low could have been an issue that was caused because not maintained?
Thanks so much
Marlene

DEF evaporates leaving that creepy white crystal film on everything. That may not be healthy for your DEF system if if it gets inside the tank. Oh I think I get it now..but why would dealer leave it this way? and how do I know it did not already get in tank...sloppy folks?

You are not "dense" My Lady!!!! ..... You are at the bottom of the learning curve!!! and accelerating!!!

RVs are complex machines. Sort of like jumping from your Camry (a Piper Cub) to an Airbus 380! One step at a time.


Well anything is possible. Poor, minimal, or lack of care i maintainence is always possible. Could be sloppy work by the techs.... Or more likely the previous owner. DEF will creep through seals and joints anywhere in the system if they are not perfectly clean and tight. A couple drops spilled in the catch groove on the fill port and a week later it looks like frost.

The fill port's cap has an "O" ring seal. It could have been damaged or was missing. New cap should fix that.

But, again.....as Aunte Crow would say: "Cleanliness is next to Godliness!"

So. Use a dedicated plastic funnel. Don't overfill. Mop up any dribs and drabs.
Refill it .... Maybe every 1500 miles...or every 4-6 diesel fillups. Top off when you store it.

If you have all the manuals, it would help you greatly to separat them in to two piles. Stuff related to the Sprinter chassis and the other pile, all the stuff related to the coach.

Get yourself a case of Keurig "Jet Fuel" coffee pods.... Start brewing!!!

Slowly organize and read the operation section of everything in the Coach and the chassis. You don't have to memorize every detail....just know where you can find it....

Dear "Old Crows"
You have given me a good advice and made me laugh, thanks! I will be adding one more stack of info to my pile to study and that is a print out of RV forums on this Coach. Sometimes I wish for the "good old days" of my first Little 1984 Toyota, water pump out? no problem lift up dinette and replace it, Holding tanks full? duh toilet won't flush. If you want hot water go out and lite the tank off! Well just to mention a few! lol I am old! However next subject is Electrical and Wiring I watched the Tech work for 2 hours yesterday to try and figure out why the slide would not open...All I could see is a huge bundle of wires (big mess) but I did see a sign saying "Slide out room circuit breaker" to me I should have been able to flip it? but no Tech says they reset themselves???????????so watch for my educational progress or not as the case maybe! I think I will skip the coffee and just have one long "happy hour".