Bubba6484

I have a 1994 Dodge Ram 2500 12 valve cummins and I have smoke coming out of my breather tube when it idles. It goes puff puff puff with the engine and it barely leaks any oil. Is it normal? If not what could it be? The truck has 304,000 miles. The breather tube is moist. The truck runs good and no problems. I just don't know how much smoke is to much smoke.

1320Fastback

These motors are pre smog and are vented to atmosphere. Vapor/smoke coming out of breather under the truck is normal.

Bubba6484

Okay thanks it just worried me because the smoke can be seen and when sittin at a stopligt I can see a little smoke coming from the front of the truck. I didn't know if it was something major or not

AlpineRAM

You should take a look at your vacuum system, quite a lot of the older trucks have a lot of leakage there, and alll the air the vacuum pump pulls in get vented through the breather tube.
And all the dirt it gets through the leaks ends up in the oil pan..

Bubba6484

I have a receipt for the previous owner and it has had a 3 section early vacuum pump repair kit. So the pump was rebuilt recently. Could it be the orings?

AlpineRAM

Could be anything. Had some where the softer parts of the vac lines had rotted away, on others some of the hoses had rubbed through.
I would run the truck and simply plug the vac connector on the pump and observe the blowby. If it reduces drastically you know you will have to search for the leak somewhere "upstream", so re-connect hose, plug other end, check etc. If you have a vacuum brake bleeder you can use that to isolate the leaking segment.

oldblues

rebuilding mine at 330.000 mi due to broken rings !

puff,puff,puff , check your compression rear cylinders uasualy fail first due to heat !