Why is my crankcase building pressure?
#1
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Location: Chapel Hill, NC
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Why is my crankcase building pressure?
96 in my sig. I've been seeing more and more oil under my truck in the mornings...Added oil the other day and forgot to put the filler cap back on. No more oil puddle. Put filler cap back on, more oil on driveway. Put several layers of cloth over the filler instead of the cap. 25 mile trip and the rag is oil saturated. The oil leaks causing the puddles are coming from the seal on the crank shaft (replaced 25k miles ago when I killed the KDP) from the overflow tube and from the rear of the motor (possibly RMS?) What is causing my crankcase to pressurize enough to push oil out these seals?
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I had a rubber elbow at the vacuum pump develop a hole in the bottom side that greatly contributed to the crankcase vent tube oil smoke plume. (vac pump discharges to the crankcase.)
I replaced the elbow and the flow greatly reduced.
If you have some time for some reading, do a search on oil blowing out of the dipstick tube. There are some detailed answers about various causes of excess crankcase pressure.
Hope yours is simple.
K.
I replaced the elbow and the flow greatly reduced.
If you have some time for some reading, do a search on oil blowing out of the dipstick tube. There are some detailed answers about various causes of excess crankcase pressure.
Hope yours is simple.
K.
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I have the same exact issue. I checked my vac lines, they are all fine, so that wasn't it for me. I ended up fixing the symptom by buying a 2 in 1 oil fill/breather part to replace my current oil fill tube. Part number is 3944797 from Cummins, about $46. Please let me know if you ever figure out what is causing your buildup in crankcase pressure!
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#9
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Your blowby filter could be clogged and causing too much pressure thus the oil is being forced out of the engine. What kind of oil have you been using? If you are using a non-diesel rated oil, chances are this could be your problem. If you will do an advanced search using "blowby" in the key words field, "Infidel" in the User Name field and select the 12 Valve Engine & Drivetrain forum you will find lots of reading on this. Hope this helps you out.
John (DH)
John (DH)
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Thanks guys. Did a compression test 5k miles ago when I had the injectors out (long story). All 6 were between 490 and 510. I'll check all the guesses tomorrow and report back.
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