Def Smell in Cab

[Jmartinez2934]

Hello everyone this is my first time posting and I’m looking for anyone’s input. I have an 18 Ram that has been smelling like ammonia for about 2 weeks. Decided to investigate so I removed the back seats as well as the carpet and noticed Def fluid had soaked it all back there. There is even small pools of def under the carpet. I searched under the truck around the engine around the tank even the injector and not a single drop. Anyone have any idea what could be going on. Thank you

 

[crash68]

Follow the line from the injector on the SCR to the top of the DEF tank under the truck, there should be signs of DEF leaking. If you don't see signs of DEF along the line or at the top of the tank then it's probably not DEF under the back seat.
Check the vents on the back wall of the cab, one of them is probably leaking.

 

[mtofell]

Liquid on the floor under the backseat sure makes me think leaking 3rd brake light. Ammonia smell? Once water gets in and mixes with carpet, etc. and sits for a while, it can take on all kinds of crazy smells.

 

[06 Dodge]

Hello everyone this is my first time posting and I’m looking for anyone’s input. I have an 18 Ram that has been smelling like ammonia for about 2 weeks. Decided to investigate so I removed the back seats as well as the carpet and noticed Def fluid had soaked it all back there. There is even small pools of def under the carpet. I searched under the truck around the engine around the tank even the injector and not a single drop. Anyone have any idea what could be going on. Thank you

Not sure how you would get DEF in the cab being the tank is filled through the opening in the bed, its next to the one for diesel

 

[Jmartinez2934]

Liquid on the floor under the backseat sure makes me think leaking 3rd brake light. Ammonia smell? Once water gets in and mixes with carpet, etc. and sits for a while, it can take on all kinds of crazy smells.

Could this just be my problem if I can’t locate any def leak by the lines or tank? On the other hand, there was some kind if crystallization on the carpet and under it and border of the plastic pieces.

 

[mtofell]

Could this just be my problem if I can’t locate any def leak by the lines or tank? On the other hand, there was some kind if crystallization on the carpet and under it and border of the plastic pieces.

Yeah, I think there's a lot of junk in carpet and pad and everything else down there that could lead to smells, crystals, etc. Has your truck been in the rain lately or through a carwash? Read up on the third brake light thing... it's a super common problem but a super easy fix.

 

[nlambert182]

Unless someone spilled DEF under the seat, I don't think it's possible for any DEF leak to make its way into the cab. The entire DEF system is below the cab. DEF tank and pump are under the driverside footwell, and the injector is on the passenger side roughly under the passenger seat area.

Definitely recommend looking for either a 3rd brake light or cab vent leak. Those are pretty common. If it's a lot of water, probably the cab vent. If it's a little bit of water and staining around the headliner, your culprit is likely the 3rd brake light. Or it could be a combination of both.

 

[cnovel]

another vote for 3rd. brake light if liquid is under the back seat

what's def ?

 

[mtnrider]

It's water leaking from your rear cab vents or the 3rd brake light. It's virtually impossible for DEF to get into the cab unless you put it there. What you are smelling is probably wet carpet and mold.

.

 

[David H]

another vote for 3rd. brake light if liquid is under the back seat

what's def ?

Diesel exhaust fluid.

 

[Ritchie_Rich]

Not DEF. It’s wet, moldy carpet from a water leak. It’s impossible to get DEF in the cab, unless you put a leaking jug in there.

 

[Hemimania]

Another one for the 3rd brake light leak. Your year seems about right for that to start. Used this (which I saw on this board), issue fixed.

Tonino

 

[nlambert182]

I typically just buy this one. It's worked really well in all of my Rams. Much easier and faster than making my own. This gasket is thick and dense.