Is it normal? Def fluid coming from exhaust stack

They all do it. Or, well to some extent.
Usually it’s just morning dew/condensation/rust that is blowing out, but it would clear up once up to operating temperature.

 

No it's not normal. DEF fluid should not injected before SCR reaches high enough temperature to decompose fluid into water and nitrogen. Probably DEF doser valve is leaking or DEF lines not purged after engine shut off. With this DEF can leak down in to SCR and blowed out exhaust when you start engine.

 

Imagine that a big truck pissing Urea all over the road.... ugh. That cannot be normal.

Whoever created this emissions monstrosity should be shot.

 

Shooting is to easy,they should be clubbed to death like baby seals. Lol

 

Picture?

Your can often see dried ash running down the back. DEF is another story....

 

several of the macks i’ve seen are like that. they’ve all had a def issue at some point but are racking up miles with no real problems.

 

dbl post

 

Do you have a picture ?

 

It is normal. My '2017 pete has 8 inch pipes from dealership . They connect them like it should be done and def was all over the cab just after ten mile bob tail road test. So they had to make them dummy and run weed burner setup. My other friend 388 was doing the same. Others Volvo same bs.. i i wder why government doesn't give clean idle trucks any rebates as with electric cars.. we are saving the planet too by not deleting our equipment lol