[9297oldram]

I wonder if the transmission cooler is putting to much extra heat through the radiator. Do you have a trans temp gauge to see what your trans temps are running?

 

[VEF350]

The trans controller has a temp readout off of the factory temp sensor in the trans- the sensor is part of the solenoid pack so I would imagine the cooler line temp is hotter but it will keep climbing with trans temp at 170. Highest trans temp I have seen is 203 or so. I will make note to shoot the trans cooler lines next time the temps are hot and see what it is putting into the radiator.

 

[kelaog]

Hello,



Things of note-
EGT at idle seem a lot higher than my 7.3.
In drive with ac on egts on the cummins are between 550-660
in drive at idle I have a bit of black smoke out the exhaust
fan seems to be pushing air OUT the sides of the shroud - I have already trimmed more shroud to let more air out the back (towards engine) but it still throws air out the small gap between shroud and radiator

Couple things stood out to me in this list.
1. EGT's are way too high at idle. I think you have a timing or injector issue to be honest. This is evident by the black smoke at idle, high EGT's, and high jacket water temps.
2. Fan should be a pull type. It is somewhat normal for a fan blade to throw air radially away from the fan blade. This is how centrifugal pumps work.
3. Are your electric fans mounted in front actually causing a significant restriction on the air flow? Are they moving air the same way as the mechanical?

To be honest, spend most of your time on #1. I'm betting it resolves your overheating issue.

I've had a similar issue before and the coolant temps dropped way down when the timing was corrected.

 

[9297oldram]

Couple things stood out to me in this list.
1. EGT's are way too high at idle. I think you have a timing or injector issue to be honest. This is evident by the black smoke at idle, high EGT's, and high jacket water temps.
2. Fan should be a pull type. It is somewhat normal for a fan blade to throw air radially away from the fan blade. This is how centrifugal pumps work.
3. Are your electric fans mounted in front actually causing a significant restriction on the air flow? Are they moving air the same way as the mechanical?

To be honest, spend most of your time on #1. I'm betting it resolves your overheating issue.

I've had a similar issue before and the coolant temps dropped way down when the timing was corrected.

I kinda wondered about the Ducky injectors myself.

 

[VEF350]

1. EGT's are way too high at idle. I think you have a timing or injector issue to be honest. This is evident by the black smoke at idle, high EGT's, and high jacket water temps. That is what I was wondering but have not been able to find much info searching. Is there an easy way to check VE pump timing while on the truck? I am guessing the injectors would just have to be removed and sent off to be tested to rule injectors out? Just noticed what looks like #5 injector leaking around hold down last night after 700 or so miles so I will have to pull the lines off anyway.
2. Fan should be a pull type. It is somewhat normal for a fan blade to throw air radially away from the fan blade. This is how centrifugal pumps work. I am thinking maybe I need to figure out a shroud that is closer to the radiator or somehow get the fan back further so it is creating more of a suction through the shroud rather than throwing the air around inside.
3. Are your electric fans mounted in front actually causing a significant restriction on the air flow? Are they moving air the same way as the mechanical? They are mounted inside the front bumper blowing the air into the condensers lower half (toward engine) where there is currently no airflow probably due to the poor shrouding. I guess I need to go back to the drawing board on the shroud and try to see what other people doing these swaps are using though I have seen a lot use the stock shroud like I have.



I've had a similar issue before and the coolant temps dropped way down when the timing was corrected. Sounds like that is what I will focus on now. Thanks!

 

[9297oldram]

A injector leaking around the hold down nut usually just means to tighten the nut some more and the leak usually stops. If it doesn't stop then there must be dirt at the sealing surface copper washer.

I would have the injectors tested.

 

[VEF350]

I will see if tightening the nut stops the leak for now so I can move the truck around. Interesting, the only fuel injection shop I can find in town said they don't charge to pop test mechanical injectors/check for leaking. Is that all that is required to rule out the injectors? Seems hard to believe anything is free lol.

 

[9297oldram]

The Pop pressure is real important on a mechanical injector.

 

[Antonm]

Isn't the VE pop pressure lower than the P7100?

If it is, and injectors set at P7100 pop pressure are installed, that should retard the injection events, not advance them.

Which could explain the black smoke at idle I suppose, if the injection events were happening a lot later than they're suppose to. Could that cause high idle EGT as well?
.
.
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[9297oldram]

Isn't the VE pop pressure lower than the P7100?

If it is, and injectors set at P7100 pop pressure are installed, that should retard the injection events, not advance them.

Which could explain the black smoke at idle I suppose, if the injection events were happening a lot later than they're suppose to. Could that cause high idle EGT as well?
.
.
.

Yes the injector pop pressure is different and if I remember correctly P-Pump injectors are a different thread on the injector nuts.

 

[VEF350]

Also it only seems to smoke at idle in drive when there is a load on the motor. If I am sitting at a light and the wind is blowing toward the front of the truck I can see smoke coming by lol. Once it is in park/neutral its gone as far as I can tell.

 

[Destroked 450]

I don't think your having a air flow issue with the fan and shroud, I'm running a second gen fan with a 7.3 shroud with no over heat issues
FYI air flow is highest at the outer edge of the shroud on any mechanical fan setup with the most air moving out to the side at a 45 60 degree angle or more
We trimmed a 1/2" or 1 inch off my shroud just to gain better access to the belt tensioner without consideration on how deep the fan was inside the shroud
Here's the best photo I have of my fan and shroud spacing, the fan is still up inside the shroud, as far as shroud to radiator spacing everything is in it's factory position.

Are you using a 1st gen or 2nd gen water neck, 2nd gen has a small air bleed hose to eliminate air pockets

Mine's a ZF6 manual but it's been in the mid to upper 90's here while I hauled 20 loads like in the photo out of fields with no over heat issues

 

[VEF350]

That is awesome to see that you have the exact same fan/shroud setup and have no issues. I am starting to think the excessive EGTs are the main problem but I cant help but think that for whatever reason my fan with or without shroud is only pulling air through the middle of the radiator and that I can feel and see it (with paper held up) blowing air back the wrong way through the radiator only at the corners that I have something weird going on. On the 7.3 I can feel it sucking air through the radiator the correct way at any point on the radiator. Since I broke the shroud the other day I cant take any current pics of it on but I have a couple from a few months ago during the build. I will have to grab another shroud and play with it. I am using the 1st gen water neck with no bleed hose, and I have my heater hose coming off of the fitting where your bleed hose goes to in the head. Can you feel any air being blown out the the front of your shroud? where the shroud meets the radiator?

Drove the 7.3 to work today to get comparisons to radiator inlet and outlet temps. I will update after the drive home in 100 degree temps.

F350 12V 3.73, 33.5" tall tires towing 19' ski boat, 38 miles

Ambient 79F - Radiator inlet 187F Radiator outlet 155F
Ambient 99F - Radiator inlet 204F Radiator outlet 189F

F250 7.3 3.73, 36" tall tires towing 19' ski boat , 38 miles

Ambient 75F - Radiator inlet 168F Radiator outlet 125F

 

[kelaog]

Could that cause high idle EGT as well?

Yep. It's an U shaped curve.

Too little timing and the fuel is still burning as the exhaust valve is open and also, if it's injected too late then the piston is already on its way down so less of the fuel energy is converted into work (ie: converted into heat). The combustion quality is poor for a number of reasons but in a diesel engine it would be because of poor atomization and because a good chunk of the fuel is chasing the flame front while it's being injected.

Too much timing and you have combustion trying to force the piston down when it's got a long ways to come back up. The result is that you get incredibly high force on the crank due to excessive piston pressures and that excessive pressure generates a tremendous amount of heat.

Probably some better explanations out there but that's my understanding of it.

 

[VEF350]

Are we talking enough adjustment in the slotted holes to make timing far off enough to cause something like this? It is a major pain to get to that back pump bolt but I will gladly retard/advance the pump with the adjustment slots if it could be off that much. Pump was locked when I got it back from being rebuilt, lined up to "E" on cam gear. I did have to pull the pump after cam break in to fix tappet cover leak but I did not remove the front cover, just locked the pump, removed, and slid back into gear/keyway.

 

[9297oldram]

Pushing the IP to just about all the way to the head isn't to much timing, I have my there and so do alot of others. It's the best way to remove unwanted smoke when you have your IP turned up.

I would have the injectors pop tested.

 

[kelaog]

Are we talking enough adjustment in the slotted holes to make timing far off enough to cause something like this? It is a major pain to get to that back pump bolt but I will gladly retard/advance the pump with the adjustment slots if it could be off that much. Pump was locked when I got it back from being rebuilt, lined up to "E" on cam gear. I did have to pull the pump after cam break in to fix tappet cover leak but I did not remove the front cover, just locked the pump, removed, and slid back into gear/keyway.

If the pop test is free, start there...If those are good then there may be something off with your injection pump (despite it being rebuilt).

I think the timing gear is set correctly to stock.
Timing marks on pump drive gear. | Dodge Cummins Diesel Forum (cumminsforum.com)
Timing Question | Dodge Cummins Diesel Forum (cumminsforum.com)

 

[VEF350]

Ok. Cool. One other thing I was wondering. If by some chance the injectors were much larger than what I ordered (5x12) it seem like that might also cause similar problems. The flow specs for my pump are below. When I first got everything together the smoke/egts were nuts. I had to back off the smoke screw 5 full turns and rotate the fuel pin from where they had it when it was built (most aggressive setting) to almost the least aggressive setting. I talked to the pump builder and he said it should not have smoked crazy with only 5X12 with the way he set it up. I gave him all the build info before he rebuilt the pump. Injection shop in town said they could pop test injectors and test for leakage, but he said he would try to retard the pump and see what effect it has.


stock fuel pin and screw, 366 gov spring

1000 rpm/ 0 psi boost- 70cc
1500 rpm/ 0 psi boost- 100cc

1500 rpm/ 20 psi boost- 160cc
2000 rpm/ 20 psi boost- 160cc
2500 rpm/ 20 psi boost- 160cc
3000 rpm/ 20 psi boost- 150cc
3200+ rpm defuel

 

[kelaog]

Ok. Cool. One other thing I was wondering. If by some chance the injectors were much larger than what I ordered (5x12) it seem like that might also cause similar problems. The flow specs for my pump are below. When I first got everything together the smoke/egts were nuts. I had to back off the smoke screw 5 full turns and rotate the fuel pin from where they had it when it was built (most aggressive setting) to almost the least aggressive setting. I talked to the pump builder and he said it should not have smoked crazy with only 5X12 with the way he set it up. I gave him all the build info before he rebuilt the pump. Injection shop in town said they could pop test injectors and test for leakage, but he said he would try to retard the pump and see what effect it has.


stock fuel pin and screw, 366 gov spring

1000 rpm/ 0 psi boost- 70cc
1500 rpm/ 0 psi boost- 100cc

1500 rpm/ 20 psi boost- 160cc
2000 rpm/ 20 psi boost- 160cc
2500 rpm/ 20 psi boost- 160cc
3000 rpm/ 20 psi boost- 150cc
3200+ rpm defuel

I suspect your issue would get worse with timing more retarded than not but that would probably prove out the theory. I think you're in a very retarded condition (the engine, not you personally).

Other thing that could cause your issue is air in the lines/pump. Diesel fuel is basically incompressible, air is not. If you're not developing the right injection pressure then your atomization is poor and the injectors may not be popping at the right time either.

 

[Destroked 450]

Tell me about the thermostats you had and are presently running, were they both for 1st gen engines, there is a difference between 1st and 2nd gen thermostats