Looking at a Link-Belt 130x3 with an Isuzu engine that has around 7500 hrs. (Isuzu AM-4JJ1X engine) Seems to run good but I pulled the fill cap off the valve cover with the engine warmed up and idling. Good thing I had some shop rags because in about 2 seconds my hand, face, and glasses were splattered with oil. It had quite a bit of pressure blowing out the valve cover which was spitting out oil everywhere. Funny thing was, not much of anything was coming out the crankcase breather tube. How bad is bad on these engines? At this amount of blow-by does it have broken rings?
Worn valve guides can cause the same symptoms.
Good day Maybe the crankcase breather is blocked, you could check out the ring & valve condition with a compression test. There are similar posts at "Club Isuzu" Kind regards Uffex
You can get a lot of splash from those engines. They put a massive amount of oil into the rockers all the time. I always checked crankcase pressure with a water tube manometer connected to the dipstick tube. Factory spec on that was one inch of water at full load on the engine. There are gauges that are calibrated in inches of water that can also be used. The other thing to think about is that the emissions stuff installed on engines today end up with more pressure in the crankcase normally. Does you engine have positive crankcase ventilation, selective catalytic reduction and a diesel particulate filter?
I can see the rockers spitting oil out a little on the top of the valve cover but this was a lot more than that. It was spitting all over the top deck of the machine, on my glasses, face and hat. Putting your hand above the oil fill hole it didn't just spatter your hand, in a couple of seconds it looked like I'd put my hand palm down in a puddle of oil. Unfortunately, I didn't think to video it. If it hadn't been for this I would have been a serious buyer of the machine. Nice handy size machine. I could have brought it home, used it for this summer, and if needed I could have overhauled it next winter....but I'm not after another project. I just watched it sell a little bit ago and it brought good money, but if they buyer didn't look at it they may have a surprise. Incidentally, I found where the owner had bought it at auction about 18 mo. ago. It brought $7800 more than he paid for it. A sign of the times. Thanks for the replies.