Excessive Oil Compsuption 5.9 24V Cummins

[Cummins12V98]

Ok it does not leak you like the truck it does the job you want it to so what’s the big deal if you add a quart every 1,500 miles???

Like I said WORK that engine it may surprise you.

 

[Joe Mc]

Tremendo, I appreciate your concern about oil loss and not really being able to nail down where it is being lost/consumed. Hopefully the Dino oil (non-synthetic) will do the trick, not sure why but if it does then "Bada-Bing!" Enjoy your new "to you" truck. Keep us posted on how things progress.

 

[KrisKringle]

I see this thread is a bit old. My truck has 200K on it now, and has never used more than 2 quarts between changes. Since the last oil change, the truck has practically changed the oil itself; 8 quarts in 6K miles or so!

No external leaks. I changed the tappet cover when I put in the Blue Chip Diesel pump. Vacuum leak? I replaced the porous elbow at the vacuum pump a while ago. I will check the lines along the cowl and try a leak-down test with a vacuum pump.

Suspecting the Turbo is the culprit. I pulled off the inlet-side hose and it (Turbo) looks pretty grungy on the inlet side; black and greasy. I will pull off the down pipe tomorrow to confirm. I never shut the engine down hot, and always wait for the Turbo temp to go below 300 degrees. I have noticed a bit of "growl" when the turbo spins down immediately after shutting the engine down.

Oh yes, the thing lets out blue /grey smoke on acceleration.

 

[GAmes]

Vacuum leak?

Not unless the main inlet hose to the pump is disconnected. The leak from one 1/8 inch hose can not pressurize the crankcase enough to cause that much blowby. If all your vacuum operated equipment is operating you can rule that out.

 

[KATOOM]

Sounds like the turbo seals are bad and oil is being consumed.

 

[KrisKringle]

Sounds like the turbo seals are bad and oil is being consumed.

I will confirm tomorrow, but that is the direction I am going.

 

[Rich Poirier]

Tremendo, do a search here for vacuum leaks causing blowby here on the forum. There are threads for this particualar situation. I am with Boeing diesel, especially because I experienced this with my truck. Vacuum leaks cause an imbalace of vacuum/pressure causing excessive blowby. I noticed it on my truck just while sitting at a stoplight. Replace the hose at the vacuum pump, follow all the lines under the weatherstripping at the cowl. Mine were like charcoal and literally powdered in my hand. Also take a peek at the lines that operate the 4 wheel drive system underneath, from the transfer case on. The square rubber manifold atop the transfer case is notorious for leaking bigtime. You can omit the manifold and just run the 4 lines directly to the TC. Just get rid of that issue all together. Maintaining your vacuum lines are just as important as maintaining your grounds on these trucks. Fixed my problem by the way. And ran so much better. Your oil viscosity is relative to your demographic ie, elevation, average temps during particular seasons. I run Rotella 5w40 because I run at 5000', an arid climate, Northern Arizona, and do 50/50 city/highway driving with Amsoil filters. Don't over-think this unless your engine is just running horrible. Many times the small things are the big answers with our trucks.

 

[GAmes]

Tremendo, do a search here for vacuum leaks causing blowby here on the forum. There are threads for this particualar situation. I am with Boeing diesel, especially because I experienced this with my truck. Vacuum leaks cause an imbalace of vacuum/pressure causing excessive blowby. I noticed it on my truck just while sitting at a stoplight. Replace the hose at the vacuum pump, follow all the lines under the weatherstripping at the cowl. Mine were like charcoal and literally powdered in my hand. Also take a peek at the lines that operate the 4 wheel drive system underneath, from the transfer case on. The square rubber manifold atop the transfer case is notorious for leaking bigtime. You can omit the manifold and just run the 4 lines directly to the TC. Just get rid of that issue all together. Maintaining your vacuum lines are just as important as maintaining your grounds on these trucks. Fixed my problem by the way. And ran so much better. Your oil viscosity is relative to your demographic ie, elevation, average temps during particular seasons. I run Rotella 5w40 because I run at 5000', an arid climate, Northern Arizona, and do 50/50 city/highway driving with Amsoil filters. Don't over-think this unless your engine is just running horrible. Many times the small things are the big answers with our trucks.

So, in fact, none of your vacuum operated devices worked, correct? Because if they all work the vacuum loss can not possibly be the cause of excessive blowby.

 

[KATOOM]

Oh...here we go again.

 

[GAmes]

Oh...here we go again.

It's tough to kill internet myths. Did the device you unhooked for your video work while you were filming? Obviously not.

 

[KrisKringle]

So, in fact, none of your vacuum operated devices worked, correct? Because if they all work the vacuum loss can not possibly be the cause of excessive blowby.

Tea-kettle test done a while ago. with 200K miles, I doubt the rings are toast. The PO (Previous Owner) had a K&N filter on the thing, that went in the trash first.

 

[KrisKringle]

Tremendo, do a search here for vacuum leaks causing blowby here on the forum. There are threads for this particualar situation. I am with Boeing diesel, especially because I experienced this with my truck. Vacuum leaks cause an imbalace of vacuum/pressure causing excessive blowby. I noticed it on my truck just while sitting at a stoplight. Replace the hose at the vacuum pump, follow all the lines under the weatherstripping at the cowl. Mine were like charcoal and literally powdered in my hand. Also take a peek at the lines that operate the 4 wheel drive system underneath, from the transfer case on. The square rubber manifold atop the transfer case is notorious for leaking bigtime. You can omit the manifold and just run the 4 lines directly to the TC. Just get rid of that issue all together. Maintaining your vacuum lines are just as important as maintaining your grounds on these trucks. Fixed my problem by the way. And ran so much better. Your oil viscosity is relative to your demographic ie, elevation, average temps during particular seasons. I run Rotella 5w40 because I run at 5000', an arid climate, Northern Arizona, and do 50/50 city/highway driving with Amsoil filters. Don't over-think this unless your engine is just running horrible. Many times the small things are the big answers with our trucks.

I did not have time to check the lines today. Way back when, I also had an oil consumption issue VERY similar to this one. I turned out it was a bad "T" in the vacuum lines. I need to look closer, but it is like the shoemakers' kids going barefoot. (I am now a working as a mechanic at a shop here in Germany). Also did not have time to look at the other side of the Turbo. Next change will be Wednesday, since I am booked solid with A Dodge Viper, a POS Hummer, and an Ex-Army K30. Oh, and I need to smoke ribs for the Parents of my Wife's Day-Care.

 

[KrisKringle]

I did not have time to check the lines today. Way back when, I also had an oil consumption issue VERY similar to this one. I turned out it was a bad "T" in the vacuum lines. I need to look closer, but it is like the shoemakers' kids going barefoot. (I am now a working as a mechanic at a shop here in Germany). Also did not have time to look at the other side of the Turbo. Next change will be Wednesday, since I am booked solid with A Dodge Viper, a POS Hummer, and an Ex-Army K30. Oh, and I need to smoke ribs for the Parents of my Wife's Day-Care.

Tremendo, do a search here for vacuum leaks causing blowby here on the forum. There are threads for this particualar situation. I am with Boeing diesel, especially because I experienced this with my truck. Vacuum leaks cause an imbalace of vacuum/pressure causing excessive blowby. I noticed it on my truck just while sitting at a stoplight. Replace the hose at the vacuum pump, follow all the lines under the weatherstripping at the cowl. Mine were like charcoal and literally powdered in my hand. Also take a peek at the lines that operate the 4 wheel drive system underneath, from the transfer case on. The square rubber manifold atop the transfer case is notorious for leaking bigtime. You can omit the manifold and just run the 4 lines directly to the TC. Just get rid of that issue all together. Maintaining your vacuum lines are just as important as maintaining your grounds on these trucks. Fixed my problem by the way. And ran so much better. Your oil viscosity is relative to your demographic ie, elevation, average temps during particular seasons. I run Rotella 5w40 because I run at 5000', an arid climate, Northern Arizona, and do 50/50 city/highway driving with Amsoil filters. Don't over-think this unless your engine is just running horrible. Many times the small things are the big answers with our trucks.

All of my vacuum devices work. Also did a rebuild of the Vacuum pump when I changed the PS pump. (Prophylactic change, at 200K wear and tear-noticed better breaking as a result)

I run 15W-40 Megain, a C3 rated full-mineral oil with Zink. The Truck is in Germany, Western Germany. It also does TONS of runs on the Autobahn at speeds of 75-85 MPH on the way to Job-sites in Holland and France (still do a little carpentry/cabinet work for the "right" customers)...jeez, I hate getting passed.

 

[GAmes]

Tea-kettle test done a while ago. with 200K miles, I doubt the rings are toast. The PO (Previous Owner) had a K&N filter on the thing, that went in the trash first.

My post was aimed at Rich Poirier, that is why I quoted him. A little boost leak causing blowby is physically impossible. You can not suck enough air through a 1/8 inch hose to pressurize a chamber with a 3/4 inch vent.

 

[Signal73]

We did work on a 2g 24v one time, and in the process knocked the vacuum line off the pump and the guy went out for a test drive and came back leaking oil from the road draft tube. Looked around figured what we did wrong hooked back up the hose and oil leakage subsided.

 

[GAmes]

We did work on a 2g 24v one time, and in the process knocked the vacuum line off the pump and the guy went out for a test drive and came back leaking oil from the road draft tube. Looked around figured what we did wrong hooked back up the hose and oil leakage subsided.

I can believe that. The vacuum pump opening is large enough to suck in enough air to influence the crankcase pressure that the engine produces. If the engine has enough wear, that could be the straw that breaks the camel's back. The lack of vacuum operated gizmos should be the first indication of an air leak though.

 

[KrisKringle]

My post was aimed at Rich Poirier, that is why I quoted him. A little boost leak causing blowby is physically impossible. You can not suck enough air through a 1/8 inch hose to pressurize a chamber with a 3/4 inch vent.

I beg to differ, when the first instance of oil use was noticed (before the vacuum pump rebuild) it was due to a faulty connection in the vacuum lines...I will post a proper diagnosis on Wednesday.

 

[GAmes]

I beg to differ, when the first instance of oil use was noticed (before the vacuum pump rebuild) it was due to a faulty connection in the vacuum lines...I will post a proper diagnosis on Wednesday.

Please provide the physics involved. I'll pass them on to the city water works who are apparently foolish enough to think large water mains are needed when 1 inch PVC will be plenty.

 

[Rich Poirier]

GAmes, think outside the box! An accumulation of bad "1/8" lines plus the 1/4 at the pump will cause issues. Lose the attitude bro. We're here to help not puff our chests.

 

[GAmes]

GAmes, think outside the box! An accumulation of bad "1/8" lines plus the 1/4 at the pump will cause issues. Lose the attitude bro. We're here to help not puff our chests.

I guess you didn't read post #56, to wit;
"I can believe that. The vacuum pump opening is large enough to suck in enough air to influence the crankcase pressure that the engine produces. If the engine has enough wear, that could be the straw that breaks the camel's back."

In your case, the following applies. "The lack of vacuum operated gizmos should be the first indication of an air leak though."

Just so you know, there isn't "An accumulation of bad "1/8" lines plus the 1/4 at the pump". There is one inlet to the pump, approx 1/4 inch but all the 1/8th lines connect to it. In other words, there isn't an accumulation plus, there is just one 1/4 hole if the entire system is disconnected. In a healthy, stock engine, physics would dictate that even that 1/4 inch hole could not suck enough air into the crankcase to overpower a 3/4 inch vent to the atmosphere. If you modify the engine to high HP, the engine will have significant blowby, so if you have increased your power and have a worn engine the blowby will occur all by itself. The point of all this is the fact that by itself the vacuum pump cannot cause EXCESSIVE blowby, period. Don't believe me? Spend a few bucks to build a home made manometer and measure the pressure difference yourself with a line disconnected. You can get fancy ( https://www.cumminsforum.com/forum/94-98-engine/232657-checking-blowby.html ) or you can suspend a U shaped clear hose, connected to the oil dipstick hole with some water in it. Suspend the other end to the hood, mark the water levels and start the engine. You will get an immediate indication of crankcase pressure. Disconnect a 1/8 inch line and see for yourself you little difference there is. Rev the engine a little. The pressure will increase slightly but not much.

I am SMH about these comments that you made. "Vacuum leaks cause an imbalace of vacuum/pressure causing excessive blowby" and " And ran so much better. " Curious of what balance of pressure there is in the crankcase, and how does the vacuum system influence how well the engine runs?