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bigdomino 07-31-2012 06:05 PM

Have a 2008 Monaco Knight with a Cummins ISC 330 horse engine. I pull a Honda CRV.

When traveling the engine usually runs between 180 and 190 degrees. Let me qualify to say that is usually on the flats in the eastern part of the country. Today, I was traveling east on route 80 in Nevada going over a grade east of Elko. I believe it was 6% for some length. Outside temperature was 91 degrees. The engine temperature reached 199 degrees for a short period during the climb. It has never gotten that high before. I believe transmission reached over 190 degrees.

Is this pretty normal? Temperature dropped down once over the hill.

I noticed that I can get a temperature drop if I **** the transmission down into 4th. Running on the flat with the outside running 90 plus degrees, the coach runs between 179 and 185 degrees.

Let me know how I compare to some of you out here.



Perry White 07-31-2012 06:11 PM

You can't beat them temps. My Trans been up to 205. 100 degree out.Engine runs between 190- 215.

Mr_D 07-31-2012 06:16 PM

That's what ours runs at too even with it being a 350 with the Banks on it. As long as the temps hold steady and come right back down there's no problem.

GaryKD 07-31-2012 06:20 PM

My ISC 330 runs at the same temp as in the OP.

GaryKD 07-31-2012 06:28 PM

Hi bigdomino,
I have the same engine as you. In the scenario mentioned in the OP, my engine would be at 210+. All the other temps are the same as yours. I am at 37K+ lbs GCW.

Perry White 07-31-2012 06:41 PM

I'm thinking the best thing to do is put tape over the gauges and just watch for smoke when it rolls out the back. Less worry. Same outcome.

SteveLevin 07-31-2012 06:46 PM

My ISC runs at a solid 180 in level conditions, climbing hills, it depends on conditions. At altitude on a hot day I've seen 215 at the end of a long, hard 6% pull, but typically 6% grades are well under 200.


bigdomino 07-31-2012 07:22 PM

What is the max temperature before the engine shuts down?


JimM68 07-31-2012 07:37 PM

mine, also an 08 knight, with a 360hp, never ever gets over 185, trans at 175.

you aren't getting anywhere near bad temps, but it may be time to flush out the outside fins of the radiator. I do mine every spring and every fall, and sometimes once in between.

bigdomino 07-31-2012 07:41 PM

I flushed the exterior of the radiator before I left California. Usually do it every year.

What is the shut down temperature?


Crabby Mike 07-31-2012 07:41 PM


Originally Posted by bigdomino (Post 1261992)
What is the max temperature before the engine shuts down?


Call Cummins with your engine serial number. They will happily answer all your questions, and you won't have to wonder if you got the right answer.

That's not to slight those who answer with their temps -- those are good data points. I have an ISL, and would not be at all worried about the temps you've seen.

SteveLevin 07-31-2012 08:11 PM

FWIW I run the exact same temps in those conditions with my ISC (300/950) on that same stretch of road under those conditions. Don't forget that you are up at a solid mile+ of elevation, and in the hot summer, if you actually calculated density altitude, you'd find it was close to 10,000'. Hot, thin air doesn't help cooling.


deandec 08-01-2012 12:45 PM

My owners manual says the 300hp 8.3L Cummins has a thermostat that will not fully open until 205 degrees.

225 degrees is an automatic shut down and it will.

RickO 08-01-2012 12:51 PM

Your temps seem fine to me too.

I downshift to keep the RPMs near 2000 when pulling a long climb in hot weather.


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