What's With the Blow By On My 5.9?
06-01-2015, 01:10 AM
#1
Registered User
Thread Starter
Join Date: Sep 2007
Location: Interlake Region, Manitoba, Canada
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
What's With the Blow By On My 5.9?
I have a 2001 5.9 24 valve engine with only 165,000 US miles on it. The truck is well looked after with frequent oil and filter changes. I have been having a problem with blow by at the front breather hose,( the one with the little bottle on it). This has been getting worse over time, and oil drips from the bottle and gets all over the engine, blown around by the fan. I looked for a pc valve, but none found, and my manual does not show one on this engine. I don't think my engine should have this much blow by with such low mileage on it. Any ideas or solutions?
2001 Dodge Ram 3500 4x4 Dually. 5.9 Cummins. Auto transmission. Stock unaltered. 165,000 mi.
2001 Dodge Ram 3500 4x4 Dually. 5.9 Cummins. Auto transmission. Stock unaltered. 165,000 mi.
06-01-2015, 07:27 AM
#2
Administrator
I would suggest getting rid of that stock "catch bottle" Dodge supplied with the truck! They are NOT up to the task of catching the oil that comes out of the blow-by tube. What happens is the engine fan blows alot of the "oil vapor" onto and around that bottle in the front of the engine. So,....in many cases the residue oil looks worse than it is and makes an owner think there is a problem with the engine.
On my 2002 Dodge CTD 24 valve, I ran a longer flexible tube down near the front suspension and then got a good catch can from "Summit Racing" to catch that oil. I have the same basic set-up on my 1996 Dodge CTD 12 valve drag race truck with no problems at all. By getting a better "catch can" you can measure the oil consumption and go from there. Also, check your oil dipstick to see how much oil you are actually losing.
I will try to get some links and pictures up here for you on the "catch cans".
Good luck!
----------
John_P
On my 2002 Dodge CTD 24 valve, I ran a longer flexible tube down near the front suspension and then got a good catch can from "Summit Racing" to catch that oil. I have the same basic set-up on my 1996 Dodge CTD 12 valve drag race truck with no problems at all. By getting a better "catch can" you can measure the oil consumption and go from there. Also, check your oil dipstick to see how much oil you are actually losing.
I will try to get some links and pictures up here for you on the "catch cans".
Good luck!
----------
John_P
06-01-2015, 07:31 AM
#3
Administrator
Otis:
Here is a link for you from "Summit Racing" on some of their "oil catch cans."
http://www.summitracing.com/search?S...20catch%20cans
Also, you can check your local "Auto Zone, Advance Auto or O'Reilly" Auto Parts stores as many of them have them too. And you don't need a real expensive one either.
Here is a link for you from "Summit Racing" on some of their "oil catch cans."
http://www.summitracing.com/search?S...20catch%20cans
Also, you can check your local "Auto Zone, Advance Auto or O'Reilly" Auto Parts stores as many of them have them too. And you don't need a real expensive one either.
06-01-2015, 10:27 AM
#4
Registered User
otis.2010, the 2nd gen Cummins ISB engines are "open loop" emissions. Meaning, there is no EGR or PCV valves on this engine and the crank case literally vents out into the atmosphere. Thats what everyone is referring to as "blowby". The way it vents is out the timing gear assembly via the 3/4" rubber hose and down to that catch bottle with a couple holes in it.
That said, its pretty cool that these truck have ZERO emissions garbage to deal with, clean, or replace, but the way Cummins vented this engine in the Dodge is terrible. Not because it vents atmospherically but because the engine fan blows approximately 10,000 cfm. So what happens is the fan blows a lot of the oily air onto the engine but.....it also takes a lot of the blowby and sucks it back around the radiator and gets the radiator all oily too. Then dirt and debris sticks to the oil and over time you get a partially clogged radiator. Nothing you can visually see either as its behind the shroud and stuck deep within the fins but you'll eventually know its happening because the truck will start to run hotter when you tow and the A/C will become a little warmer when the truck is only idling and not moving. Also, there's no way to properly clean the radiator unless you remove it. Easy to do but understood that most dont care to go through the effort. If you search around the internet you can even find pictures of people who've removed their radiator only to find a large clean circle in the middle of their radiator and the rest clogged up with junk.
To address this problematic issue, what people do is take off the catch bottle, go down to the local hardware store and pick up a 3/4" hose connector and some length of 3/4" heater hose. Connect to the blowby vent hose and extend the length of line down below the engine and away from the fan. Some even extend further. Like me who has enough 3/4" extension that my engine vent exits as far back as the fuel tank area. I just mke sure that the hose is secured to the frame and that there's no dips or sags deep enough to allow oil puddling in the hose which may eventually block the venting.
Now, another thing to point out is the catch bottle isnt necessary. Get rid of it..... As some people think the bottle is "catching" all this oil, the bottle is really the mess maker, not the oily blowby. Removing the catch bottle altogether is best. If you're worried about drips then understand that if it drips at all, it would be hardly anything. Generally the only thing that drips is the collected oil residue in the hose which warms up on a hot day and allows a drop to hit the garage floor. There's really no point in measuring what comes out of the bottle since you can tell whats left in the engine merely by the dip stick. And.....the catch bottle makes it seem as if there's volumes of oil coming out the engine too but thats not the case.
Now, to make this all even more confusing..... The amount of blowby can seem considerable while the engine is idling. And if the hose is now located far enough from the engine fan then you'll see a slight haze in that area because there's no fan blowing it all over. But, if you're experiencing an excessive amount of blowby venting, like air forcefully pumping out the hose then you most likely have a vacuum issue whereby the vacuum pump is shoving air into the crankcase and its coming out the vent hose harder than normal. This happens because there's a vacuum line somewhere cracked or disconnected. But most of the time if the vacuum leak is this bad then then you'll also have trouble with your HVAC vent selections as well since they're vacuum controlled. People who see all the blowby venting mistakenly think their engine rings are worn out too but thats not the case.
That said, its pretty cool that these truck have ZERO emissions garbage to deal with, clean, or replace, but the way Cummins vented this engine in the Dodge is terrible. Not because it vents atmospherically but because the engine fan blows approximately 10,000 cfm. So what happens is the fan blows a lot of the oily air onto the engine but.....it also takes a lot of the blowby and sucks it back around the radiator and gets the radiator all oily too. Then dirt and debris sticks to the oil and over time you get a partially clogged radiator. Nothing you can visually see either as its behind the shroud and stuck deep within the fins but you'll eventually know its happening because the truck will start to run hotter when you tow and the A/C will become a little warmer when the truck is only idling and not moving. Also, there's no way to properly clean the radiator unless you remove it. Easy to do but understood that most dont care to go through the effort. If you search around the internet you can even find pictures of people who've removed their radiator only to find a large clean circle in the middle of their radiator and the rest clogged up with junk.
To address this problematic issue, what people do is take off the catch bottle, go down to the local hardware store and pick up a 3/4" hose connector and some length of 3/4" heater hose. Connect to the blowby vent hose and extend the length of line down below the engine and away from the fan. Some even extend further. Like me who has enough 3/4" extension that my engine vent exits as far back as the fuel tank area. I just mke sure that the hose is secured to the frame and that there's no dips or sags deep enough to allow oil puddling in the hose which may eventually block the venting.
Now, another thing to point out is the catch bottle isnt necessary. Get rid of it..... As some people think the bottle is "catching" all this oil, the bottle is really the mess maker, not the oily blowby. Removing the catch bottle altogether is best. If you're worried about drips then understand that if it drips at all, it would be hardly anything. Generally the only thing that drips is the collected oil residue in the hose which warms up on a hot day and allows a drop to hit the garage floor. There's really no point in measuring what comes out of the bottle since you can tell whats left in the engine merely by the dip stick. And.....the catch bottle makes it seem as if there's volumes of oil coming out the engine too but thats not the case.
Now, to make this all even more confusing..... The amount of blowby can seem considerable while the engine is idling. And if the hose is now located far enough from the engine fan then you'll see a slight haze in that area because there's no fan blowing it all over. But, if you're experiencing an excessive amount of blowby venting, like air forcefully pumping out the hose then you most likely have a vacuum issue whereby the vacuum pump is shoving air into the crankcase and its coming out the vent hose harder than normal. This happens because there's a vacuum line somewhere cracked or disconnected. But most of the time if the vacuum leak is this bad then then you'll also have trouble with your HVAC vent selections as well since they're vacuum controlled. People who see all the blowby venting mistakenly think their engine rings are worn out too but thats not the case.
06-01-2015, 06:13 PM
#5
Administrator
KATOOM:
No offense to you Sir as I know you give alot of advice to our members, but I totally disagree with you about the oil catch cans. If they are installed right and the connections from any type hose to the can is tight they DO NOT cause any problems! I know because I have two (2) of them on my 1996 Dodge CTD Drag Truck and the one in the front is right below the fan but fits tight and keeps the area clean. Yes, they have to be emptied but I like not having all that "oil residue" on the underside of my truck.
I guess Otis will have to decide what he wants to do with his particular truck.
No offense to you Sir as I know you give alot of advice to our members, but I totally disagree with you about the oil catch cans. If they are installed right and the connections from any type hose to the can is tight they DO NOT cause any problems! I know because I have two (2) of them on my 1996 Dodge CTD Drag Truck and the one in the front is right below the fan but fits tight and keeps the area clean. Yes, they have to be emptied but I like not having all that "oil residue" on the underside of my truck.
I guess Otis will have to decide what he wants to do with his particular truck.
06-01-2015, 06:52 PM
#6
Registered User
John, no offense taken and I fully appreciate your opinion too. Thats the joy of these forums. Multiple suggestions but whatever someone does is "to each is own".
I agree, aftermarket catch bottles "can" function well but the Cummins version is just lame. I've even seen someone fabricate a really cool catch container mounted to the side of the frame with a small K&N looking filter on the top. Pretty neat looking but more work than I care to go through. And it looked expensive too.
In regards to the underside of my truck though..... If it wasn't for the ever leaking transfer case tail shaft seal weeping ATF fluid around the front u-joint, my truck would be spotless under there.
I agree, aftermarket catch bottles "can" function well but the Cummins version is just lame. I've even seen someone fabricate a really cool catch container mounted to the side of the frame with a small K&N looking filter on the top. Pretty neat looking but more work than I care to go through. And it looked expensive too.
In regards to the underside of my truck though..... If it wasn't for the ever leaking transfer case tail shaft seal weeping ATF fluid around the front u-joint, my truck would be spotless under there.
06-02-2015, 09:04 AM
#7
Administrator
John, no offense taken and I fully appreciate your opinion too. Thats the joy of these forums. Multiple suggestions but whatever someone does is "to each is own".
I agree, aftermarket catch bottles "can" function well but the Cummins version is just lame. I've even seen someone fabricate a really cool catch container mounted to the side of the frame with a small K&N looking filter on the top. Pretty neat looking but more work than I care to go through. And it looked expensive too.
In regards to the underside of my truck though..... If it wasn't for the ever leaking transfer case tail shaft seal weeping ATF fluid around the front u-joint, my truck would be spotless under there.
I agree, aftermarket catch bottles "can" function well but the Cummins version is just lame. I've even seen someone fabricate a really cool catch container mounted to the side of the frame with a small K&N looking filter on the top. Pretty neat looking but more work than I care to go through. And it looked expensive too.
In regards to the underside of my truck though..... If it wasn't for the ever leaking transfer case tail shaft seal weeping ATF fluid around the front u-joint, my truck would be spotless under there.
KATOOM:
Thanks so much for your reply Sir.
I do agree with you that Dodge's stock set-up with that plastic bottle oil catch can is LOUSY! I am going to try and get a picture up here for the OP,
you, and my fellow DTR members on what I did on my truck. I have one of those "custom made" catch cans you mentioned BUT, my Son John Jr. is a
mechanical engineer and has access to a large machine shop in his company with all kinds of different metal etc. and machines. So,....we spent a day, for free making the one on my truck. Granted, not all members have that but some of the aftermarket companies do make some good units. I forgot to mention that running the drag racing circuit with NHRDA, ODSS etc. our drag trucks HAVE to have the catch cans to keep the oil off the drag strips we run at.
Thanks again for your input and help to our members Sir!
---------
John_P
Trending Topics
06-02-2015, 02:46 PM
#8
Registered User
Thread Starter
Join Date: Sep 2007
Location: Interlake Region, Manitoba, Canada
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
That's great info to look into guys. As a matter of fact, Katoom, your description sounds exactly dead on for my issue. There is a lot more blow by than earlier, and my hvac is stuck on defrost mode. I'm going to look for a vacuum leak before going any further.
06-02-2015, 08:29 PM
#9
Registered User
06-02-2015, 08:41 PM
#10
Administrator
Yep, classic sign of a big vacuum leak. In the loss of vacuum, the HVAC defaults to defrost mode, cruise control is lost (for the vacuum operated servo models), and some 4x4 setups lose the ability to engage the front axle.
The "exhaust" of the vacuum pump is the crankcase, and when there's a vacuum leak (especially a big one), more air moves though the vacuum pump into the crankcase, and then out the crankcase breather. This looks like a significant cylinder problem, but is usually traced back to the vacuum system.
There is an even more common vacuum pump problem, where the shaft seal between the vacuum pump and power steering pump (they share the same shaft) leaks. Oil leaks out, and air leaks in causing more "blowby". This happened to my pump. The fix is pretty straightforward but kind of a pain in the rear to do.
Hope you find a simple fix for your system.
The "exhaust" of the vacuum pump is the crankcase, and when there's a vacuum leak (especially a big one), more air moves though the vacuum pump into the crankcase, and then out the crankcase breather. This looks like a significant cylinder problem, but is usually traced back to the vacuum system.
There is an even more common vacuum pump problem, where the shaft seal between the vacuum pump and power steering pump (they share the same shaft) leaks. Oil leaks out, and air leaks in causing more "blowby". This happened to my pump. The fix is pretty straightforward but kind of a pain in the rear to do.
Hope you find a simple fix for your system.
06-02-2015, 11:22 PM
#11
Registered User
Thread Starter
Join Date: Sep 2007
Location: Interlake Region, Manitoba, Canada
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Got It!! Broken vacuum line on the fire wall. Easy fix and my hvac is now working normal again, and blow by seems reduced again. Hey jrs You saw my other post on the subject Stuck on Defrost. I thought that I had two problems that just seemed to occur around the same time, so that's why I made posts in two locations. I decided to do something about the catch bottle problem as well. I have had the truck since 2007, and many times wondered what the reasoning was with locating the bottle here. Even at the best of times it leaves oil residue at the front of the engine, which eventually makes it's way further back. I removed the bottle and added about a foot or so of heater hose and ran it down and faced it somewhat to the rear. Hopefully there is nothing illegal about it. Next step was a trip to the car wash to clean up some of the oil mess. I will give this a try. I would be interested to hear about the vacuum pump seal repair just in case this becomes a problem in the future. Regards.
06-03-2015, 08:55 PM
#12
Registered User
What you did is perfectly legal. Think about an engine venting its crankcase into the open atmosphere..... Cant get much more unfriendly with the environmentalists than that.
06-04-2015, 06:48 AM
#13
Administrator
Yeah KATOOM that's right,......old man Gale Banks would DEFINITELY not like that!
06-04-2015, 07:22 AM
#14
Administrator
Hopefully your radiator isn't gunked up too bad either. Oily mist from the breather, plus the fan swirling it around, plus dirt/dust tend to clog up the radiator.
06-04-2015, 04:27 PM
#15
Registered User
Thread Starter
Join Date: Sep 2007
Location: Interlake Region, Manitoba, Canada
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Clean Up
Went down to the car wash and cleaned things up as best I could. I paid a lot of attention to cleaning the rad, but it's not easy to see exactly how clean it is. I think the answer is to get another person to look on the other side while I spray water through the rad. It may not prove how clean the rad is, but should at least show if it is plugged in some areas.