Hi all. I have a Lull 8042, about year 2003, 4800 hrs. It has worked great all last year since we got it. Today I was driving it home and it would get to 3rd gear then start losing power. I would downshift then I would have to totally stop, after about 30 seconds I could go again but same thing would happen. I noticed oil pressure gauge going down to almost zero when I would have to stop. Other gauges looked good. Any help would be greatly appreciated.
Sorry everybody, not 8042, It is a Lull, 8000 lb lift, 42 or 44 foot reach, got mixed up reading about these things for the last 2 hours trying to find information. Thanks
Just to clarify, are you saying this is an engine problem? Does the engine rev normally if you stop when it does this, or does it limp and sputter for a while? and then recover? If it's barely running then the low oil pressure is to be expected, low rpm=low oil volume/pressure. What kind of engine and fuel system?
In neutral it would rev normally, I can have it revved all the way while extending forward and traversing forward and tilting the forks and it works just fine, but try to go down the road even in second gear it would gradually slow down in about 30 seconds.
by the way, what is standard engine oil psi, I am pretty sure it is a Cummins, definitely diesel.
Until somebody who knows what they're doing happens along, I'll take a shot at this. What kind of gauge do you have? Standard oil pressure is 2/3 or better of the gauges movement. If the engine is idling much slower than it should, the oil pressure will be lower than normal idling oil pressure. You have checked the engine oil level and kept an eye on the temp gauge, right? This sounds like a fuel starvation issue, maybe something blocking the supply, intake-screen-pump-filter etc. Or what does the injection pump look like? do the lines come out of the end in a circle, or out of the top in a row, or is there a visible injection pump? That sounds like what the cummins in the Dodge did when the vp pumps (rotary) went bad.
engine oil level is good, temp was about 160, oil gauge goes from 0-80, I believe, with 20,40, 60 marked off, oil pressure would be about 20 when driving it then slowly go all the down till I stopped.
Not good, very bad. If the oil pressure is steadily dropping below 20 at faster than idle then shut the machine off immediately. You could try checking the oil pressure with a different pressure gauge, maybe this one is a leaker and there is a engine protection system that cuts power with low oil pressure reading? I'm grasping at straws on that one. Only other thing I can think of is oil dilution, what does the oil smell like? Hey, what part of WI are you in?
I am thinking your right, pressure didn't drop till rpm started going down (low rpm-low pressure). I just jumped on the pressure idea because a buddy who was looking at it with me said the pressure should be way more than 20 psi. But I was doing some reading on other sites about Cummins and read that they run with low oil oil pressure. So I am going to change fuel filter and try that. Oil is good. Coolant is good. I'm from around Green Bay. Forecast is calling for a high of almost 50 degrees, quite a change from -15 last week.
Changed fuel filters, now it runs great. Looks like bigger chunks of rusty metal in the inline filter, don't know where that is coming from. Thanks for the help, Delmer.