Excessive oil out of the breather
I have a 2012 International 4300 with the twin turbo Maxxforce DT that is having a lot of oil being pushed out of the blowby tube. I initially replaced the breather assembly because I figured it was plugged up and it seemed to have cleared up the oil leak at first. After the truck had been driven several times the whole lower right side of the engine was covered in oil. We pressure washed the engine and let it run on high idle for several minutes and found oil was coming out of the blowby tube at a pretty steady rate. I am looking for any pointers as to the possible cause.
How many miles on the engine sounds like excessive blow by worn rings could cause this
It usually takes some crankcase pressure to force oil out of a breather tube. Can you measure that? You should have none. Excess pressure is usually blowby often caused by bad top rings since the only pressure source is the combustion chamber.
I have no way measure the exact amount of pressure coming out of the breather tube but I can block it off with my hand for a couple seconds at 1500 rpm and when I remove my hand there seems to be a decent amount of pressure released.
The truck has 269,242 miles on it. I just took over the fleet back in August of last year and from what I have gathered from the drivers and seeing the condition these trucks are in nothing has been taken care of. Luckily we are upgrading our fleet so I just need to keep the trucks we have running until June/July time frame until the new ones come in.
Hi Phillip, Put a vacuum gauge on the oil dipstick tube and watch for pulsing frantically. This sounds like it is due for an in frame due to excess ring and cylinder wear. The next issue could be a cracked or burnt piston from a failing injector.
I don't have a plug big enough to seal up the dipstick tube.
This is a short video of what's coming out of the dipstick tube at idle
I would say its inframe time.. there is an adapter that fits roaddraft tube and you use a magnehelic gauge to measure the blowby, IDK specs but based on your info, i would agree with the others, worn out or broke piston.
Phillip, I ran into this same issue a couple years ago on a similar truck. There's actually a post on here about it. Here's the link diag.net/msg/m6ghkrj5qc… Rex Unkefer is a much better resource for this than I am but here's the long and short from what I recall. If you can, perform a relative compression test either with scan tool or scope and sync to see if any cylinders are…
Does it have any boost pressure codes?? A badly failed turbo bearing in one of turbo can cause this….if shaft is broke in one of turbos…..
My scanner is down at the moment trying to get the company to buy a new one but, that's a different conversation. I had to have my guy pull the truck out of the shop to fix another truck that we use daily. I will have him look into the turbo when I can get it back in the shop.
Phillip, read thru the link Zachary posted. Pretty much the whole story. IF you rebuild be sure to convert to open crankcase if that has not been done. Look at the tube coming out of the side of the breather. If it turns up and connects to a big hose going onto the turbo inlet it is a closed system. For test disconnect from the turbo inlet hose. Clean off that area. Start it up and run it. Heck…
We worked on one of these on rear engine school bus,navistar need their buts kicked on that application ….almost impossible to work on….
Marvin, Is it the engine or the application? I do not see a lot of rear engine buses but the few I have come across over the years all have access problems no matter whose engine it is. Are some better that others. And lets not even talk about motor homes!
Well my tech had to replace exhaust manifold gasket on it,had to pull both turbos etc,,,,had to work on his knees for 4 hpurs just to get it apart…..that was drives side of engine,on the other side thet had a sideways mounted radiator with a hydralice drived fan motor with all the hydralic lines and resevoirs etc,,,we had to replace a couple of injectors on same bus,the ac compressors ahd to…
Your guy did good. 4 hours to get the exhaust manifold off would be decent on a normal conventional. Never mind what you had! EGR cooler is a PIA on those also as the turbo has to come off.
That would be nice but that's not going to happen. We're in the process updating our fleet so that won't be an option. An in frame is even going to out of the question. Hopefully it's just a turbo
KME is currently doing that per some fire people I know. About $68,000. Pre 2010 engines Cummins has or had a program. Especially for buses. Post 2010 becomes almost impossible price wise because an SCR system has to be added. It can be justified with fire apparatus due to the high replacement cost.
… Turbos do NOT make pulses out the crankcase like that… what you are seeing there is some SERIOUS blow by on (what looks like to me) one cylinder…sounds like they are going to waste a bunch of money…. Dan H. … Hobbs.
Dan my comment about the turbo can put exhaust back into crankcase is if the wheel and shaft is broke and allowing exhaust to go from behind turbine wheel into crankcase,,,,,didnt watch his video about it puffing,,,if wheel and shafts are tight in turbo and not broke,he shoudnt change them just to see,, apair of those is expensive …
But I just thought of something we just had on a cummins in firetruck was excessive crankcase pressure….guess what it was,,,,,,bad air compressor,finally caught it was blowing black motor oil out of air drier on to particulte filter filter and ground
The company is selling the truck