EGT too high

[hilda]

This is my 3rd CTD the first I’m Bombing and the first one I’ve installed an EGT gage in. Now when I’m towing a 6% grade with my 6500lb 5th wheel, I had to back off and down shift, I’m getting into the 1100 range. The next trip same pass without the trailer I had the same issue. This is ridicules I’ve heard guys on here going up the same pass (Cajon pass) at 60 mph pulling 15000 lbs passing car.



Is my high EGT due to the stock 3” no muffler exhaust or is the power puck not that great? I was in Flagstaff AZ last month and the truck ran awful 5000ft. It seams the truck comes alive after 2000rpm. I can brake the tires loose going into 3rd and there lots of smoke, but this is of little use when you’re towing, up and down hills.



Thanks in advance.

 

[ThrottleJockey]

1100 pre or post turbo? If it's pre turbo, 1100 degrees is a walk in the park. Aluminum pistons start to melt at around 1300 degrees PRE TURBO. 1250 is the working limit.



Lowering your EGTs is as simple as buying a bigger turbocharger. More air, more power with the SAME fuel and less heat, or more air, same power with LESS fuel, and susequently, less heat (EGT)



Besides, big turbos are cool.

 

[HBarlow]

Hilda,



I put 325,000 miles on an '01. 5 with 275 hp motor home injectors pulling trailers 50% to 100% heavier than the one you are pulling. The truck has the NVG-5600 transmission and 3. 54 gears. I routinely pulled grades at 1325 degrees and occasionally the pyro would peg at 1600 degrees briefly before I backed out of it. You will not hurt your engine pulling grades at sustained EGTs of 1300 degrees. My truck never suffered any failures and is still in daily use as a work truck for my s-i-law's company. It may be true that aluminum begins melting at 1300 degrees but a piston only reaches maximum temperature for a very brief period (milliseconds?) during and following combustion and it has oil cooling jets spraying it from underneath and a cylinder wall with coolant chambers surrounding it at approximately 200 degrees. In order to limit your EGT to 1100 degrees you must limit fueling which will limit your engine power to maybe only 150 horsepower.



The Gen III common rail engines like in my '06 have better metals in pistons, valves, and valve seats and are rated by Cummins to run continuously at as much as 1450 degrees. I routinely pull hills heavily loaded with my current truck at 1425 to 1450 degrees. It has 226,000 miles on it already and shows no ill effects.



Our Cummins engines were designed and built to run at full throttle against the rev limiter all day pulling heavy loads. They are truck engines, far more tolerant of hard use than some seem to believe.



Put your foot in it and enjoy the power of your Cummins engine pulling the steep grades. That's what it was designed to do.



Harvey

 

[hilda]

Ok



I installed the probe pre-turbo. I guess I'm being too cautious, I see that needle in the yellow and my foot starts to back off. I just bought this truck and the turbo and exhaust manifold are discolored like they were over heated and it did not have a gage, maybe this is why I'm careful.



It looks like we are moving to Wyoming and I'll be pulling the 15000 lb 38ft Cedar Creek there and I want the truck ready.



Thanks again

Hilda

 

[MRiley]

Ok



I installed the probe pre-turbo. I guess I'm being too cautious, I see that needle in the yellow and my foot starts to back off. I just bought this truck and the turbo and exhaust manifold are discolored like they were over heated and it did not have a gage, maybe this is why I'm careful.



Thanks again

Hilda

I was the first and only owner of my '01. The manifold has the same discoloration. I can assure you that it has never gone over 1300. I think the color cahnge just happens with time.

 

[KLockliear]

As mentioned above, 1250*F is the continuous work limit. Above that for short bursts is OK. I've seen these trucks take WAY more, but I wouldn't recommend it for every day. In town, if I see 1500*F, that's no big deal for a few seconds as the piston doesn't have enough time at those temps to do anything bad. On a long hill though, different story.

 

[JDiepstra]

Hilda, a 4" exhaust would help lower temps a bunch. That is my non scientific based opinion. But it will help!

 

[Blu-meanie]

Everything on the engine was laquered when new. That is what discolors.

 

[hilda]

Hilda,



I put 325,000 miles on an '01. 5 with 275 hp motor home injectors pulling trailers 50% to 100% heavier than the one you are pulling. The truck has the NVG-5600 transmission and 3. 54 gears. I routinely pulled grades at 1325 degrees and occasionally the pyro would peg at 1600 degrees briefly before I backed out of it. You will not hurt your engine pulling grades at sustained EGTs of 1300 degrees. My truck never suffered any failures and is still in daily use as a work truck for my s-i-law's company. It may be true that aluminum begins melting at 1300 degrees but a piston only reaches maximum temperature for a very brief period (milliseconds?) during and following combustion and it has oil cooling jets spraying it from underneath and a cylinder wall with coolant chambers surrounding it at approximately 200 degrees. In order to limit your EGT to 1100 degrees you must limit fueling which will limit your engine power to maybe only 150 horsepower.



The Gen III common rail engines like in my '06 have better metals in pistons, valves, and valve seats and are rated by Cummins to run continuously at as much as 1450 degrees. I routinely pull hills heavily loaded with my current truck at 1425 to 1450 degrees. It has 226,000 miles on it already and shows no ill effects.



Our Cummins engines were designed and built to run at full throttle against the rev limiter all day pulling heavy loads. They are truck engines, far more tolerant of hard use than some seem to believe.



Put your foot in it and enjoy the power of your Cummins engine pulling the steep grades. That's what it was designed to do.



Harvey

Harvey





All the reading I've been doing when it comes to injectors the RV275 seams to be the best for overall performance. Were you happy with them?



Hilda

 

[HBarlow]

Hilda,



Yes, they work great. They really woke my HO 6 speed '01 up. It would accelerate stronger and faster and would pull grades in 6th OD pulling a trailer that previously required a downshift to 5th direct. The only drawback to them is more fueling = higher EGTs.



Talk to Joe Donnelly, a TDR contributing editor. I bought the injectors from Joe at the first TDR rally I attended, in Kerrville, TX fall of '01. Joe also installed them. They are still in the truck and it now has about 350k on the odometer.



Harvey

 

[hilda]

Hilda,



Yes, they work great. They really woke my HO 6 speed '01 up. It would accelerate stronger and faster and would pull grades in 6th OD pulling a trailer that previously required a downshift to 5th direct. The only drawback to them is more fueling = higher EGTs.



Talk to Joe Donnelly, a TDR contributing editor. I bought the injectors from Joe at the first TDR rally I attended, in Kerrville, TX fall of '01. Joe also installed them. They are still in the truck and it now has about 350k on the odometer.



Harvey

Thanks Harvey



The 275's will be on the list. Sounds like they are the way to go.



Hilda.

 

[EBung]

Everything everyone has said is great advice but one more thing is i'm not sure if the puck you have does any boost fooling so you might also be a little boost limited.

 

[steved]

I'm just going to comment about your 5000 foot comment... that's normal. Less air at higher elevations takes longer to build boost to build power. You should have seen my STOCK 3rd gen at 10k feet, it smoked like a freight train!

steved

 

[DCreed]

high flow air box/filters help as well as larger exhaust. get a boost elbow the HX35 can push 35psi safely, the headgasket can do 45psi. w/reasonable drive pressures. I've gone to a HTBG turbo, 100hp injectors, a Amsoil 4510 filter, and 4" exhaust. pulling 10k trailer up long hills is not an issue and I dont need to look at the pyro anymore. a mild tuner and mild injectors is a proven combo for towing, as long as they get sufficiant airflow in & out of the engine. Also, you dont want to "lug" it too much, if rpm's are down too low you cant build enough boost and EGTs will skyrocket. Above 1800-2000 rpms should pull anything.

 

[hilda]

Everything everyone has said is great advice but one more thing is i'm not sure if the puck you have does any boost fooling so you might also be a little boost limited.

Ebung





I have thought that, I'm ordering my boost and fuel pressure gage in the next few weeks. I have run the EGT's on the conservative side (nothing over 1100) so I'll take her to 1350 the next time I'm out. I'm not down on power.



Thanks

 

[hilda]

I'm just going to comment about your 5000 foot comment... that's normal. Less air at higher elevations takes longer to build boost to build power. You should have seen my STOCK 3rd gen at 10k feet, it smoked like a freight train!



steved





I can relate to the smoke I keep comparing my new truck 01. 5 5 speed to my old 98. 5 that was stock with an auto trans. (that was a great truck:{) I just drove the old truck I did not pay as much attention as I do with the new one.



Hilda

 

[GAmes]

... ... ... ... . I’ve heard guys on here going up the same pass (Cajon pass) at 60 mph pulling 15000 lbs passing car.

I'd take those reports with a grain of salt. I have pulled a lot of trailers over that pass, so I am really suspicious of those claims. And if they are really doing it, they are shortening the life of all the drivetrain. Also keep in mind you have a 5 speed, so you can't jam the power that a 6 speed can obsorb.

After multiple transmission failures I have found that the best longetivity comes from pulling hills (while loaded) in 4th gear, and keeping boost under 20 pounds. Transmission temps stay lower and 4th gear is a direct drive so there are fewer things to break.

 

[hhranch]

EGTs

Can anyone advise as to the EGT limits when the probe is mounted post turbo?

 

[HBarlow]

I've never used a post turbo probe so can't say from personal experience but TDR members generally use 300 degrees less than the pre-turbo limit as their rule of thumb. That would mean post turbo limits would be approximately 1000 degrees sustained.



Harvey

 

[TAbbott]

For whatever it's worth, Flagstaff is a lot closer to 7,000 ft elevation than it is to 5,000, but still likely less than you're going to find in much of Wyoming. The key to keeping the EGT's down is increasing the air flow through the engine and perhaps advancing the injection timing a couple of degrees.