Back again...now with bus!

[deftone]

For those following along at home, I should be making the drive to MD on Monday, so the battle will resume on Tuesday with real time updates on this thread!

 

[cadillackid]

the HPOP system varies its pressure greatly based on engine load, at idle you may have 550 PSI in that high pressure Oil rail.. punch it and you may go up to 1200+ PSI in that rail... so a really slow oil leak into a cylinder at idle or even no load higher RPM csn turn much bigger when you double the pressure.

obviously on a turbo, the faster you spin it the m,ore you can create a gyroscope effect and blow more oil out of a bad seal also.. and of course the exhaust is much hotter when you are going down the road than at idle.. all those factors can easily affect how much mosquito-fogging is going on.

-Christopher

 

[deftone]

the HPOP system varies its pressure greatly based on engine load, at idle you may have 550 PSI in that high pressure Oil rail.. punch it and you may go up to 1200+ PSI in that rail... so a really slow oil leak into a cylinder at idle or even no load higher RPM csn turn much bigger when you double the pressure.

obviously on a turbo, the faster you spin it the m,ore you can create a gyroscope effect and blow more oil out of a bad seal also.. and of course the exhaust is much hotter when you are going down the road than at idle.. all those factors can easily affect how much mosquito-fogging is going on.

-Christopher

Hmm interesting, I thought the HPOP system was kept at a constant pressure regardless of rpm. I guess it doesnt really change the troubleshooting process too much.

The mosquito-fogging was quite legendary, enough so that the traffic in the other direction actually stopped.

 

[cadillackid]

ICP is the Injection control pressure.. theres a sensor that reads back the actual pressure to the computer... the IPR regulates the pressure electronically with a solenoid and plunger based on what the computer calls for...

whats interesting about the huge smoke is that id expect to see that most if oil is getting burned in the cylinder as opposed to in the exhaust.. if theres raw oil being blown into the exhaust then it seems like that cylinder wouldnt be firing.. or at least not all the time anyway... but with a turbo i guess the EGT's can get high enough under load to Burn a lot of oil even if its dumped from the turbo bearings into the downpipe..
-Christopher

 

[tobeamiss]

Will definitely be wishing you lots of luck on Monday and waiting for the update!!
You guys are so lucky you can work on your own Buses....I hope you can figure out this mystery.

 

[deftone]

Will definitely be wishing you lots of luck on Monday and waiting for the update!!
You guys are so lucky you can work on your own Buses....I hope you can figure out this mystery.

Im trying to rush through my work today to get on the road to MD

 

[deftone]

Just a slightly different note for a minute... Ive been encountering resistance when trying to get international dealers to run my VIN so I can get some data on this bus. I finally got one to give me at least the bare minimum of information and I was kind of disappointed to see that not only do I only have the 195bhp engine, but I also have the AT545. I am assuming this isnt going to be great for a lot of long highway cruises?

How easy would it be to change over to say a 2000 series (or something else better). I believe the AT545 doesnt have lockup? Am I right?

Would a DT466 change be something possible for a non bus mechanic?

 

[Tango-SKO]

No lockup on an AT545. Have to defer to someone else regarding what it takes to mount a newer Allison on that engine. It's pretty much plug & play on a Cummins but may require an adapter on an IH. Anyone???

 

[cadillackid]

a company called Cummins Allison conversions has quoted me about 6k-7k for a complete plug N play setup (driveshaft not included). to go to a standalone Allison 1000 series on a T-444E.. the 1000 is basically the standard non OEM of a 2000...

to run it with the computer on the engine can be done also but there is more involved to do it that way... re-flashing the PCM and changing the parameter to a PCM managed transmission and then physically wiring in the TCM to the PCM..

someone else told me if the PCM on the bus supports the 2000 series then a TCM isnt required that the PCM will run it directly.. I havent pulled up the wiring diagrams for that bus yet to see if the 1999 PCM's supported direct transmission control or not..

running it standalone mean you will have a simple TPS to mount up typically in [place of the allison modulator cable on older modeld.. or on newer models it connects to the accelerator pedal and connects to the transmission..

the Bell on a 545 should be re-usable on a 1000 negating the need for an adapter plate.

the 1000 is about 3/4" longer than a 545.. on a 2 piece drieshaft its likely you'll have to shorten that front drieshaft or move the carrier bearing back (assuming theres enough clearance on the rear driveshaft slip Yoke)..

-Christopher

 

[deftone]

a company called Cummins Allison conversions has quoted me about 6k-7k for a complete plug N play setup (driveshaft not included). to go to a standalone Allison 1000 series on a T-444E.. the 1000 is basically the standard non OEM of a 2000...

to run it with the computer on the engine can be done also but there is more involved to do it that way... re-flashing the PCM and changing the parameter to a PCM managed transmission and then physically wiring in the TCM to the PCM..

someone else told me if the PCM on the bus supports the 2000 series then a TCM isnt required that the PCM will run it directly.. I havent pulled up the wiring diagrams for that bus yet to see if the 1999 PCM's supported direct transmission control or not..

running it standalone mean you will have a simple TPS to mount up typically in [place of the allison modulator cable on older modeld.. or on newer models it connects to the accelerator pedal and connects to the transmission..

the Bell on a 545 should be re-usable on a 1000 negating the need for an adapter plate.

the 1000 is about 3/4" longer than a 545.. on a 2 piece drieshaft its likely you'll have to shorten that front drieshaft or move the carrier bearing back (assuming theres enough clearance on the rear driveshaft slip Yoke)..

-Christopher

Wow, lots of great information! Thank you! That price is a little too steep for me considering the low miles per year I will be running. I guess I will run it till she dies! Perhaps swapping a complete motor/transmission combo will be an easier and more cost effective option?

 

[cadillackid]

I was reading more on a CAT forum about a 3126 that has an issue similar to yours.. it turns out oil in the fuel supply internally inside the injector is a fairly common failure..

the HEUI system was originally thought up and patented by CAT then IHC and CAT worked together to put it in production...

the basic operation is that there is no high pressure fuel pump like in a "normal" diesel, instead the HPOP produces a high oil pressure which is applied to a diahpram in the injector.. that diaphram uses a Plunger to to inject the fuel shot into the cylinder.. the fuel pressure is amplified in the injector... should the oil diaphram within the injector fail oil could come into contact with the fuel and be injected into the cylinder.. (at least thats how I read the pieces online into this guy's CAT experience..).. the particular ended up being found by accident as they couldnt figure where the oil was going and why the emgine smoked.. it was thought to be fuel so they sent their injectors out to a shop to be tested only to find one damaged.. when all 6 were repaired or replaced.. the engine ran perfect...

so dont rule out injectors after the turbo is replaced if things still domt work right...

im reading more and more about how these HEUI injectors cause issues when they age.. even if they dont leak or fail altogether that the engines are sensitive to the spray patterns to get a good burn... lots of stuff out there on various forums that 150,000 miles is a good idea to at least have them checked by a shop.. so i may yank all mine out and have them tested since i need to put valve cover gaskets on at some point anyway... im starting to get a little seep from them.

-Christopher

 

[deftone]

I was reading more on a CAT forum about a 3126 that has an issue similar to yours.. it turns out oil in the fuel supply internally inside the injector is a fairly common failure..

the HEUI system was originally thought up and patented by CAT then IHC and CAT worked together to put it in production...

the basic operation is that there is no high pressure fuel pump like in a "normal" diesel, instead the HPOP produces a high oil pressure which is applied to a diahpram in the injector.. that diaphram uses a Plunger to to inject the fuel shot into the cylinder.. the fuel pressure is amplified in the injector... should the oil diaphram within the injector fail oil could come into contact with the fuel and be injected into the cylinder.. (at least thats how I read the pieces online into this guy's CAT experience..).. the particular ended up being found by accident as they couldnt figure where the oil was going and why the emgine smoked.. it was thought to be fuel so they sent their injectors out to a shop to be tested only to find one damaged.. when all 6 were repaired or replaced.. the engine ran perfect...

so dont rule out injectors after the turbo is replaced if things still domt work right...

im reading more and more about how these HEUI injectors cause issues when they age.. even if they dont leak or fail altogether that the engines are sensitive to the spray patterns to get a good burn... lots of stuff out there on various forums that 150,000 miles is a good idea to at least have them checked by a shop.. so i may yank all mine out and have them tested since i need to put valve cover gaskets on at some point anyway... im starting to get a little seep from them.

-Christopher

Hmm thats interesting, and I guess it makes sense. So would that mean if I was to unplug the bad injector the oil would no longer be getting injected into the cylinder? I wonder if I could run home on seven? Would it cause any lasting damage other than to my sanity since I assume I will be lacking power to get to a decent highway speed?

 

[deftone]

Two warriors enter the field of battle....who will emerge victorious?

 

[cadillackid]

if the oil is in fact being injected via the fuel supply then theoretically you should be able to stop it by unplugging whichever injector is the culprit.. if its gettig in another way then that sylinder would still burn oil..

only thing I can think of running on 7 cylinders is it would trip the WARN light which might reduce power? im not sure how advanced the diagnostics onboard are.. otherwise to me you would just have reduced power.. maybe suck a little oil on the non existent power stroke but i wouldnt think much..

ive run old gassers for long periods down a cylinder in the past.. seems a diesel wouldnt be hurt by it..

but of course the optimist says you bolt on the turbo burn the rest of the oil out of the exhaust tubes and drive happily home
-Christopher

 

[Tango-SKO]

Doesn't the fuel (oil) help lube the upper cylinder in most diesels? Maybe someone with more tech experience can jump in here but it seems like it could get a little dry up there without go-juice coming in.

???

 

[deftone]

Well the turbo as suspected did not cure the problem,

Injectors are coming out as we speak. Rather than drive home 1200 miles on 7 I think I will take the injectors for testing.

 

[deftone]

Actually I found the problem without pulling the injectors...Christopher, you called it right before when you said I should run it with the valve cover off.... The suspect cylinder with the wet manifold has a stuck valve. There is no pressure on the pushrod and I was able to lift it right out. What could be the cause? Camshaft damage? This is getting out of my comfort zone now. I assume there will be no easy fix to this?

 

[deftone]

I also assume this is what caused the marks on the valve cover, it must have been the rocker rather than the injector that hit it.

I have the pushrod out and its perfectly straight, not bent etc

 

[cadillackid]

sounds like a broken valve... oil is running into the cylnder through possibly a broken valve stem? is the retainter and stem still on it? or does that lift right out? could be a partial spring break which isnt a bad fix but likely pil wouldnt be running into the cylinder with a broken spring... ive only seen that when a valve breaks off .. I suppose it could be on the back end... closed and stuck intake valve so it sucks oil in around the rings on the intake stroke... if thats the case then its got to be a flat lifter or something i nthe cam if the pushrod and the rocker arent broken..
-Christopher

 

[deftone]

sounds like a broken valve... oil is running into the cylnder through possibly a broken valve stem? is the retainter and stem still on it? or does that lift right out? could be a partial spring break which isnt a bad fix but likely pil wouldnt be running into the cylinder with a broken spring... ive only seen that when a valve breaks off .. I suppose it could be on the back end... closed and stuck intake valve so it sucks oil in around the rings on the intake stroke... if thats the case then its got to be a flat lifter or something i nthe cam if the pushrod and the rocker arent broken..
-Christopher

Valve, rocker and pushrod all seems fine, but there is no tension on the pushrod at all. Just sits there with separation from the rocker. I assume it is the lifter. Now the question is, can it be replaced without disassembly of the motor? It would suck to tear down for a $20 part.