Originally Posted by Docsgsxr
I bought the exact year and model you have. Did you ever get that injector/oil issue resolved in your fuel?
Seems like I have a larger amount of whitish smoke than normal coming from my crank case tube and I was
wondering if I might have a similar problem with my injector(s)?
Rocking job man! I am going to start mine this summer when I get back home from New Hampshire and can't
wait!!!! (I plan on using a few of your ideas. I think the external soft white led's are a great idea!)
Sweet! Other than the shoddy, horrible electrical work done by Thomas / MCPS, they're pretty good buses. WMKbailey has the same one too, as well as ThePimentals. WMKbailey and I worked together in the fall mostly for demolition, and we found rust in similar areas, around the rear wheel wells, where salt / water would be kicked up in large quantities. Not much otherwise, and pretty easy to fix. Where did you get it from?
The O-rings probably aren't the cause of your problem. What happens when the O-rings fail is not excessive oil burning by worn rings or turbo seals, not oil going into the intake air per se, but high pressure engine oil being pumped into the fuel supply by an internal leak. Over time / wear / lack of oil changes, the O-rings wear out and stop sealing correctly. The injectors in these buses are what is called Hydraulic [over] Electric Unit Injection, or HEUI for short. They are direct-injected. Basically, instead of using an external injection pump, like an older Cummins or DT466, and running the fuel to the injectors via metal lines, the fuel is supplied to the injectors directly, at a low pressure (just enough to circulate) through a casting in the head. The engine has a seperate high pressure oil pump (think 600-800 psi, normal oil pumps are 30-100 psi depending on temp / wear) and this super high pressure oil also flows through a casting in the head, I guess parallel to the fuel. They both lead to all 6 injectors, and then the computer gives a signal (electronically controlled engine) a valve inside the injector opens, lets the high pressure oil in, which pushes down on a mechanism and pumps the fuel in at the top of the compression stroke. HOWEVER, when the O-rings fail, these 2 fluids meet, and since the oil is at hundreds of psi and the fuel only at a few, the oil gets pumped into the fuel supply, which also has a fuel return to the tank so the pump is constantly circulating around at the same rate. So a seal fails and pumps motor oil into the fuel casting area, and that gets sent back into the tank. This causes no running issues because A) there is no cylinder pressure leak and B) motor oil burns similar to diesel, so it won't smoke and sputter because it is still burning the correct amount. The only way you will know is to take a fuel sample and it is BLACK from the oil, or if you are going through an insane amount of oil but with no leaks or smoke.
I would love if you could post a video or something of the "excessive" crankcase vapor you say you have. When did you notice this? If you started it and its like 20 degrees outside, the vapor will look like more because there is some water vapor as well (byproduct of combustion) which is like exhaling outside on a cold day, looks like smoke (or in this case oil vapor) but isn't actually. Some coming out is normal, because piston rings don't ever seal perfectly, even when brand new. This only gets worse as the engines age. What you could do is drive it around for 2-3 hours, check the oil before and after and see what the consumption is like. When I first noticed the O-ring issue was when I picked up the bus from where I bought it, with totally full oil, drove it an hour and a half to where I would keep it, and the oil barely registered on the dipstick. It had gone through 2 gallons or so in that short drive with no leaks or smoke whatsoever. If the excessive blow by on your bus is what it is, than it is just worn rings from a tired engine. Not really anything you can do except replace the engine and no way that is happening. It is possible your oil is just in need of being changed, and when oil gets old it thins out and leaks by easier. Change your oil with Shell Rotella 15W-40. Near my house they sell it buy the 5 gallon jug for $70, you will need a bit more than this. A CAT oil filter is $16. PM me for part numbers.
Originally Posted by eyedeal.ink
Originally Posted by porkchopsandwiches
Thanks. Like I said though, HUGE pain in the ass. I almost lost it a few times trying to line all that up between getting cut by the panels, screws not lining up and snapping them, but it is finally done. If I ever have to take them down I'm doing so with a plasma cutter
pain in the ass but well worth it in my opinion, well done.
Thanks! I hope it pays off.