Members: Owners of the above M series, notably 7040, (glowplug: are you there?) please make the following engine check and get back to me. I don't see how in any way the check would put your engine at risk.....My engine now has 160 hrs, very careful break in (warm ups, minimal cold runs, no lugging or high rpm, steady loads, scheduled oil intervals ). I noticed a thin film of oil around the dipstick port and with the engine at operating temp and idle, I pulled out the dipstick. To my surprise, a fair amount of pressure (blow by?) is coming out of there along with some crankcase oil spray. 1) Is this normal? 2) Wouldn't this eventually compromise ft/rear seals? 3) Isn't there some kind of breather or PCV system on the engine?4) Shouldn't things be buttoned up upstairs at 160 hrs? 5) What could have happened & how to correct? If your results are the same as mine, I am relieved...but my instincts don't like it! Thanks for reply in advance bb
M XX40 series Tier II engine owners please check
- Thread starter big bubba
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Yankee Clipper
Gold Member
This engine uses a closed breather system and you should expect to see some crankcase pressure at the dipstick.
If you have enough pressure to blow the stick out, then you have stuck rings or a broken piston.
If you have enough pressure to blow the stick out, then you have stuck rings or a broken piston.
When the engine is running, there is a lot of stuff going on in there. Some air coming out is very normal. As Yankee said, as long as the dipstick stays put and doesn't fly across the yard, it's ok.
Remember, piston rings are split - they have a cut. They also have a spec for end gap. As the engine heats up with hard work, the rings expand and that gap shrinks. If you were to plow a 40 acre clay field in August at noon when it was 105F in the shade, the engine would have less leakage. Doing the check now when the temps are cold maximizes the ring gap and leakage.
Relax, all is well.
jb
Remember, piston rings are split - they have a cut. They also have a spec for end gap. As the engine heats up with hard work, the rings expand and that gap shrinks. If you were to plow a 40 acre clay field in August at noon when it was 105F in the shade, the engine would have less leakage. Doing the check now when the temps are cold maximizes the ring gap and leakage.
Relax, all is well.
jb
IH3444
Veteran Member
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- Jan 10, 2004
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This is normal at idle. The engine at idle has a tiny breather to vent outside. As the rpm's are increased above idle a one way valve in the valve cover then allows the crankcase pressure to vent directly into the intake manifold, hence an almost perfect closed system. This complys with tier II emmission standards for the EPA.