Smoke coming out of Fuel tank

You may have a bad lower injector O-ring(s) so that combustion gases (smoke) get into your fuel rail and with fuel return going to your tanks.

 

Where is the smoke emitting from on you/your wife?

 

is by chance one of your exhaust pipe near the tank ? I had a clmp break off part of my flex pipe years ago & the hot pipe laid within 1 or 2 inches from tank & heated fuel, & smoke would come out. not bad, bu enough where I noticed.

 

It is possible to get combustion into the fuel return line, if you have a bad tip on an injector. If you can look into the fuel tank when it is cold and see the fuel pick-up, look to see if it is blowing bubbles. The early ISX Cummins use to do this all the time .

 

In the old days Cat only had the two O rings on their injectors and relied on Carbon to seal the injector to head seat near the Tip.
Now they have 3 O rings and the extra O ring slides over the injector tip and this creates a temporary seal and slowly deteriorates with the heat over a short time.
However this allows the injector tip seat to carbon up and create the seal and at that time the seal which is most likely cooked has done its short term job.

If there is no seal and the combustion Gas has made its way up past the side of the Tip then it can affect the lower Injector seal and push combustion gas into the fuel rail. BUT fuel will go the other way also and you will lose any head pressure u had in the fuel rail when the engine is shut down and have hard starting not to mention fuel running into the cylinder and the odd Hydraulic lock.

 

My scania 124 L 420 year 2003 also having the same problem..it is a hpi and the o rings all changed..still having the smoke..my fren said it is normal..is it true??

 

Maybe it's a GENIE!! Were you rubbing the tank when this happened?