Can anyone identify this part on my '99 DT466E?

laegion · 04-06-2021, 12:29 AM

I am guessing this is a fuel return line on the end of my fuel rail?

laegion · 04-06-2021, 12:32 AM

Also...wtf is this cut off pipe that goes to nowhere that AmTran seems to have left on the side of my engine block? a hard vaccum line? or? Who knows...

dmattarn · 04-06-2021, 12:33 AM

First pic looks like the fuel return line. Second pic looks like the draft tube but I can't tell

laegion · 04-06-2021, 12:43 AM

Quote:

Originally Posted by dmattarn

First pic looks like the fuel return line. Second pic looks like the draft tube but I can't tell

Here's another pic that helps show the location. Currently it just ends with an open tube near the bottom of the block...just hanging out 8n the air.

laegion · 04-06-2021, 12:44 AM

Quote:

Originally Posted by dmattarn

First pic looks like the fuel return line. Second pic looks like the draft tube but I can't tell

Does yours have the intake manifold integrated into the valve cover?

dmattarn · 04-06-2021, 12:44 AM

The part you are looking at near the exhaust seems to be broken. It should go up into the valve cover

dmattarn · 04-06-2021, 12:45 AM

Quote:

Originally Posted by laegion

Does yours have the intake manifold integrated into the valve cover?

Yes all the 466e should be like that

laegion · 04-06-2021, 12:46 AM

Quote:

Originally Posted by dmattarn

The part you are looking at near the exhaust seems to be broken. It should go up into the valve cover

I thought so. It looks like someone cut it off and used that orange hose you see in the pic instead. What do you mean by "draft tube"?

dmattarn · 04-06-2021, 12:47 AM

The draft tube is the equivalent of a PCV you'd find on a gas engine. It allows gasses to vent from the crankcase.

laegion · 04-06-2021, 12:57 AM

Quote:

Originally Posted by dmattarn

The draft tube is the equivalent of a PCV you'd find on a gas engine. It allows gasses to vent from the crankcase.

Okay. I figured that must be it. Maybe for whatever reason they felt it should be routed somewhere else?

There is definitely some strange stuff on this engine and this bus... but I'm also new to diesels.

I don't seem to see a throttlebody either. and I wasn't aware that these use a fully electronic throttle...It's awesome but every new thing I learn I just come up with 10 more questions. I really need to find a service manual.

dmattarn · 04-06-2021, 12:58 AM

All throttle is controlled by fuel rate from the injectors. PM me your email and ill share the service manuals I have

dmattarn · 04-06-2021, 01:02 AM

Quote:

Originally Posted by laegion

Okay. I figured that must be it. Maybe for whatever reason they felt it should be routed somewhere else?

There is definitely some strange stuff on this engine and this bus... but I'm also new to diesels.

I don't seem to see a throttlebody either. and I wasn't aware that these use a fully electronic throttle...It's awesome but every new thing I learn I just come up with 10 more questions. I really need to find a service manual.

I completely rebuilt a junkyard 466e at my aunts house and swapped it into a flat nose front engine bus in the driveway, so I am mildly familiar with the engine lmao

laegion · 04-06-2021, 04:09 AM

Quote:

Originally Posted by dmattarn

I completely rebuilt a junkyard 466e at my aunts house and swapped it into a flat nose front engine bus in the driveway, so I am mildly familiar with the engine lmao

Mildly, huh? haha.

I appreciate the help. I'm hoping I don't have to rebuild this one right away...but looking at all this seeping oil...I'm wondering if I either have blowby or if my turbo needs a rebuild. or maybe I just need a new valvecover/intake gasket and a re-torque of this fuel return. It seems like it's seeping fuel.

That's interesting that it's controlled buy fuel rate, I was thinking it was something like that and timing, etc. I wonder if that makes it more or less responsive then an engine with a throttle body...

I'll PM you, thank you.

Truthseeker4449 · 04-06-2021, 05:18 AM

Quote:

Originally Posted by laegion

Mildly, huh? haha.

I appreciate the help. I'm hoping I don't have to rebuild this one right away...but looking at all this seeping oil...I'm wondering if I either have blowby or if my turbo needs a rebuild. or maybe I just need a new valvecover/intake gasket and a re-torque of this fuel return. It seems like it's seeping fuel.

That's interesting that it's controlled buy fuel rate, I was thinking it was something like that and timing, etc. I wonder if that makes it more or less responsive then an engine with a throttle body...

I'll PM you, thank you.

It does appear that its seeping fuel from the return line. Spray it off with something like brake cleaner and watch it with the engine running to try and pinpoint the exact leak. I strongly recommend hearing protection, as would be eye protection in case it sprays. Diesel fuel in a cut is very bad due to its high bacterial content.

Oil leaks can come from just about anything on the engine. I would recommend degreasing the entire engine before trying to trace leaks.

Mountain Gnome · 04-06-2021, 09:07 AM

Quote:

Originally Posted by laegion

Mildly, huh? haha.

That's interesting that it's controlled buy fuel rate, I was thinking it was something like that and timing, etc. I wonder if that makes it more or less responsive then an engine with a throttle body...

Gasoline only burns well at a very narrow air-to-fuel ratio. Therefore the air being sucked in needs to be "throttled" or "limited" to match the amount of fuel being used. But a motor is really nothing more than an air-pump. By limiting the air-intake, the motor has to work harder to fill the cylinder, and this takes power away from the drive-force.

Diesel burns at a very wide air-to-fuel ratio. You do not need to control the amount of air precisely, and there is no need for a throttle.

You could burn hydrogen in a motor built for gasoline, and you could just throw out the throttle body. This would make the motor even more efficient, and since it is not working against itself to suck in air, there is less wear-and-tear, and the motor will last longer.

laegion · 04-06-2021, 10:54 AM

Quote:

Originally Posted by Truthseeker4449

It does appear that its seeping fuel from the return line. Spray it off with something like brake cleaner and watch it with the engine running to try and pinpoint the exact leak. I strongly recommend hearing protection, as would be eye protection in case it sprays. Diesel fuel in a cut is very bad due to its high bacterial content.

Oil leaks can come from just about anything on the engine. I would recommend degreasing the entire engine before trying to trace leaks.

Thank you for the analysis. I don't think it's spraying as there is no spray on the inside of the dog house. It seems more like a long term seeping of some kind.
Thinking about it some more I doubt it's the Turbo as the oil couldn't make it through the IC all the way into the intake manifold...(my turbo output seems a little oily though, but that's probably a separate thing).
Looking around the engine it seems my valve cover/intake gasket may at least be partially at fault, and looking at the location of the fuel return it's at the physically lower end of the valve cover gasket area....so it may be that or a combination.
Thanks for the warning on ear and eye protection...I'd have done it anyway...even with the doghouse on, it's loud....lol. I was hoping this would be less of an issue with a dog nose bus, but I guess this engine is too long to fit fully under the hood, (maybe some more modern insulation can help.) I do however enjoy hearing the turbo spool...

laegion · 04-06-2021, 10:56 AM

Quote:

Originally Posted by Mountain Gnome

Gasoline only burns well at a very narrow air-to-fuel ratio. Therefore the air being sucked in needs to be "throttled" or "limited" to match the amount of fuel being used. But a motor is really nothing more than an air-pump. By limiting the air-intake, the motor has to work harder to fill the cylinder, and this takes power away from the drive-force.

Diesel burns at a very wide air-to-fuel ratio. You do not need to control the amount of air precisely, and there is no need for a throttle.

You could burn hydrogen in a motor built for gasoline, and you could just throw out the throttle body. This would make the motor even more efficient, and since it is not working against itself to suck in air, there is less wear-and-tear, and the motor will last longer.

Interesting! I thought I was prepared for diesels after working on my own gas engines for most of my adult life...but they are such a different animal. Lots to learn...

JamesKS · 04-06-2021, 11:44 AM

Quote:

Originally Posted by laegion

Interesting! I thought I was prepared for diesels after working on my own gas engines for most of my adult life...but they are such a different animal. Lots to learn...

Another fun fact, most diesels function on compression alone. Glow plugs do not directly ignite the fuel and most are not used until the temp is close to freezing.

laegion · 04-06-2021, 11:49 AM

Quote:

Originally Posted by JamesKS

Another fun fact, most diesels function on compression alone. Glow plugs do not directly ignite the fuel and most are not used until the temp is close to freezing.

That much I did know. I have driven a few before mid 90's Diesel Ford F-450 4x4 dually, and a diesel Fuso for various jobs. I've just never worked on one. And definitely nothing Medium-Duty.

EDIT: In fact now that I think of it...that Ford probably had the Pre-Powerstroke 7.3l turbo...because it did have a turbo on it and I'm fairly sure it was a '94...so I guess my bus is not the first International/Navistar engine I've driven. Too bad the rest of the truck was such junk...

I did find out why the crank case ventilation was re-routed. There is a filter and catch can installed on this bus.

You may also like: