Engine/Transmission (1994 - 1998) engine oil leaking out of dip stick tube

[skip1996]

I am leaving on a long trip next week and just noticed oil leaking out of dip stick onto the FI Pump of my '96. Is my crank case breather clogged? and /or what to do. Also oil dripping down onto pan from the area of the cc breather tube.

 

[Dave M]

I am leaving on a long trip next week and just noticed oil leaking out of dip stick onto the FI Pump of my '96. Is my crank case breather clogged? and /or what to do. Also oil dripping down onto pan from the area of the cc breather tube.

If it's puking oil out of the breather tube it could be something is pressurizing the crankcase... like bad rings/leaky head gasket (worst case) or maybe you just have a leak somewhere on the engine. Or. . If you overfill the oil it could puke oil for a while.



That same leak sceanario just happened to me. I lost 6 quarts one week and 6 quarts the following week. The best test (according to Cummins) is the manometer blowby test. There is a spec for acceptable blowby. I took my 97 to Cummins a few weeks ago and they tested the blowby pressure at idle and 3,000 RPM. Mine passed with 1 inch at idle and 6 inch (max is 16 inch I believe) at W. O. T.



Not trying to scare you, it may be nothing, but it should be checked out. Clean engine and verify the leak source. You can remove blowby tube and verify it is not obstructed with mud or collapsed. Also you can put a plastic bottle on end of blowby tube with hole in cap and put holes in sides at top to allow venting pressure. Then take it for a drive and see how much oil (if any) your dripping. Just leave it on there to see what happens.



The other source of crankcase pressure could be a leaky turbo intake seal allowing the turbo to pressurize the crankcase thru the turbo oil return line. Pull off the air filter hose going to the intake side of the turbo and look for signs of oil on turbo intake compressor fins or in the intercooler lines from the turbo. Also check for excessive play on the turbo shaft by pushing in on the center shaft and check for side-to-side play or fins rubbing on the housing by spinning it. If a turbo intake leak there was bad enough it could cause a run-away condition in the engine due to it inhaling the oil thru the intake and burning it.



I have read about oil leaks where the injection pump mounts to the block also. Clean up engine and check it out.



Others have said that the oil dipstick leak could be due to a bad o-ring at the dipstick that needs replaced



Others more knowledable can correct me if I'm wrong and give you further advice here.



Good luck



Dave

 

[ABorchard]

A vacuum leak can cause the vacuum pump to act like a compressor and pressurize the crankcase creating excessive blowby. With no leaks on a good system you should still have vacuum in the lines after the truck sits over night, with even a small leak the vacuum in the lines will disappear in minutes.