7.3 intake smoke

[bigblue85]

what does it mean to have smoke to come out of the intake? bad rings? too much blowby?

 

[Brianedwardss]

Is this looking down into the intake by the CDR valve? Or coming out of the intake past the air filter..?

 

[bigblue85]

straight running off the engine stand it comes out past the air cleaner past cdr valve

 

[redneckaggie]

that would prob be blowby

 

[bigblue85]

i hope its not because its gonna be a spare motor for my truck while my 6.9 is out and i need to be able to depend on it lol

 

[bigblue85]

anybody else have any ideas? i need help why does hardly anyone ever reply back to my posts lol

 

[rhkcommander]

mine'll smoke sometimes when I turn it off out the intake, just a puff. If its just CDR smoke I wouldn't worry much... If its constantly smoking out the air filter or something then ya might have problems

 

[bigblue85]

cool ya i also talked to my diesel engines teacher and he said it might be a problem with the heads or a valve seat not working properly.. think this is possible?

 

[rhkcommander]

Very possible... Other than blowby you shouldn't notice smoke, If it keeps coming then that's most likely theproblem. Justvmake sure your not looking at cdr smoke

 

[snicklas]

Is there any odd noise associated with the smoke, does it just come up like smoke from a chimney, or does it puff out in time with a cylinder firing?

I would think if it were combustion smoke, there would be a noise and puffing associated with the smoke. A member on here, 6.9poweredscout had an IH 345 gas engine with an intake valve issue, when running, especially under load, it sounded like a popcorn popper. He took a video and posted it on the site. If it looks like smoke wafting from a fire or a chimney, without any apparent force, I would agree that is from the CDR. Blowby of the rings would not be forced out of the intake, it would however, be sent out the CDR valve into the intake. If you take your oil fill cap off, while the engine is running what do you see. A small amount of smoke and vapor is normal. If you have a great deal of smoke, especially if you "break idle" and rev the engine slightly and the smoke gets worse, that is blowby. On a fairly tight engine if you break idle, the smoke should become less, possibally disappear entirely.

 

[bigblue85]

yah its like a puff everytime the engine turns over its like a puff that goes past the cdr valve. so idk it sounds great like the engine doesnt miss a beat it runs like a champ. it just has a little smoke coming out so i think it will be alright ill mess around with the cdr and see if i can steal one off my other engine and see if it helps out a little.

 

[bigblue85]

let me add to that. its on an engine stand and the vacuum pump isnt hooked up along with no water running through it. note this is just a run for thirty seconds to a minute then shut it off could this be a reason? no coolent? or is the cdr ran off vacuum?

 

[snicklas]

The CDR does not use the vacuum pump. The vacuum pump is for the power brakes, and to run the HVAC doors. I do not think no coolant would be the issue.

 

[bigblue85]

ok thanks. well i will try to clean it and see if it helps or take the heads off and check the valve seats if there bad ill just take the heads off my other engine and put them on and see how it runs then but i dont think really its an issue it just seemed odd because my 6.9 has 280000 miles and doesnt put a puff out the intake and barely out the oil fill. and it just seemed different for an engine with 130000 miles to do that. but thanks all!!

 

[snicklas]

Heads between a 6.9 and 7.3 are not interchangeable. Different bolt sizes. 6.9 = 7/16, 7.3 = 1/2