07 "blowby"

[TX_CUMMINS]

I've got a 07 cummins with the 4th rebuilt engine in it. It has signs of gasses coming out of the oil filler cap when doing the blowby test. My question is it normal if its not blowing off the cap or moving it? The mechanic who checked it out said it just needs the CCV changed on it but from I've read the 07 5.9 didn't come with one? is that true? if so I cant find one. Any help would be appreciated! truck runs and drives perfectly!

 

[Bob4x4]

The 5.9 has an oil separator under the v/cover that can be an issue and the involved plumbing can also have issues

 

[TX_CUMMINS]

The 5.9 has an oil separator under the v/cover that can be an issue and the involved plumbing can also have issues

Do you know if that's a separate part? Dealer told me that it was built into the valve cover and none of the local parts store show anything for it. Do you happen to have part numbers?

 

[cerberusiam]

The 06-07 5.9's have the oil separator built into the VC cover, nothing to replace except the cover itself. Prior to and after those years there are filters, just not those particular years. I think you can just take the cover off and cleaner the oil separator. Blow by can be subtle form broken rings or obvious from a holed piston. You will always see a constant stream of very light oils mist from a warm engine, that what th efilters and separators are meant for. If it is puffing you have issues.

 

[TX_CUMMINS]

The 06-07 5.9's have the oil separator built into the VC cover, nothing to replace except the cover itself. Prior to and after those years there are filters, just not those particular years. I think you can just take the cover off and cleaner the oil separator. Blow by can be subtle form broken rings or obvious from a holed piston. You will always see a constant stream of very light oils mist from a warm engine, that what th efilters and separators are meant for. If it is puffing you have issues.

okay that's what ive been seeing is the misty gas. not a puff. I just never had any of my older cummins do it so I wanted a second opinion! Thank you! I'm beginning to think the diesel shops around here don't really know what they're talking about because they all said change my CCV?

 

[MarkEkberg]

I just tricked myself and everyone here with a perceived blowby issue. Seems previous owner put the extension with a capped bottle on the end of it. No way for ccp to escape so it built up and pushed the hose off the back of the engine. Once reconnected it was showing pressure anytime you took the cap off..............

 

[cerberusiam]

It I shot oil laden air, it is gonna go out the easiest route. Every diesel I have ever had will do this to a certain extent, as long as it doesn't puff it is pretty normal and will vary with miles and engine wear.

 

[txslim]

I've got a 07 cummins with the 4th rebuilt engine in it. It has signs of gasses coming out of the oil filler cap when doing the blowby test. My question is it normal if its not blowing off the cap or moving it? The mechanic who checked it out said it just needs the CCV changed on it but from I've read the 07 5.9 didn't come with one? is that true? if so I cant find one. Any help would be appreciated! truck runs and drives perfectly!

change mechanics

 

[Wayne M.]

I've got a 07 cummins with the 4th rebuilt engine in it. It has signs of gasses coming out of the oil filler cap when doing the blowby test. My question is it normal if its not blowing off the cap or moving it? The mechanic who checked it out said it just needs the CCV changed on it but from I've read the 07 5.9 didn't come with one? is that true? if so I cant find one. Any help would be appreciated! truck runs and drives perfectly!

What made you concerned about this in the first place?
How many miles and hours? Has it been driven hard/ max tuned?