smoke underneath

[JG117]

Ok so i bought my truck back in February or early March. Been a minute; on the way home 167 miles to go i lost 5th gear blah blah blah anyways i got it home towed 37 miles left to go.
Truck sat until i could afford a new trans and i just got it back together last night late. I test drove it and when i got back thought id look to make sure no leaks.
Then i noticed smoke underneath its either blow by or oil burning off not sure was too dark.
Truck ran for 45 minutes after I test drove it and it didnt do it then when i was buying it, but now it does. This is my first running cummins. 98.5 24v 226,xxx miles 5 speed 4x4 1 ton.

 

[SAndreasen]

Ok so i bought my truck back in February or early March. Been a minute; on the way home 167 miles to go i lost 5th gear blah blah blah anyways i got it home towed 37 miles left to go.
Truck sat until i could afford a new trans and i just got it back together last night late. I test drove it and when i got back thought id look to make sure no leaks.
Then i noticed smoke underneath its either blow by or oil burning off not sure was too dark.
Truck ran for 45 minutes after I test drove it and it didnt do it then when i was buying it, but now it does. This is my first running cummins. 98.5 24v 226,xxx miles 5 speed 4x4 1 ton.

I would wash the underside and get all that oil off you can and wash the engine really good and get all the grease off it

 

[JR]

Are you sure you didn't just notice it, this vintage truck has a decent amount of visible blowby for lack of emissions requirements.
Perhaps post a video so we can get a better idea.

 

[NIsaacs]

Are you sure you didn't just notice it, this vintage truck has a decent amount of visible blowby for lack of emissions requirements.
Perhaps post a video so we can get a better idea.

I agree, they can produce a real light haze that you can't normally see in the day time, but at night with a light you can.

Nick

 

[BoeingDiesel]

In addition to the above, I'd check the line coming of the vacuum pump. If that tube comes loose you will see some blow by coming out of the crankcase vent tube or another way to check is if you're getting air out of all of your vents. If it's defrost only you've got a vacuum issue. I only know this because of personal experience when one day idling at a traffic light i saw an occasional puff of smoke. The rubber boot on that vac pump had cracked and thanks to the TDR someone gave me the same advice. Also, I'd think I'd take off the oil filler cap and start the motor and check for blow by and then lightly put the cap back on and watch if the cap starts popping up. Good luck