View Full Version : Water temp.

bob hyder
07-25-2006, 10:31 AM
Hi All,

I am the proud owner of a Cyclone 3795. I finally had a chance this last weekend to take it on a long weekend to the Oregon coast and ride in the dunes. What I'd like to hear from anyone with experience in there travels about what their tow rig maintains for water temps. I tow with a 2005 Dodge 4x4 2500 CTD, auto, 3.73 gears, Edge juice with attitude (on level 2, tow) and an aero flow muffler. CVWR. is about 21,000-22,000 lbs. My experience is: temp outside was 101* to 104*, towing freeway, 55-60 mph, 207*-208*. Going around someone or up small hills, 214*-216*. Towing at 65-68 mph, Temp was 203*-205*. Going up small hills in towns off the freeway it would climb to 225*. On my way back I have to go thru a small town that has a pretty steep hill but only a half mile long and the temp hit 226*. Always cools down to 207* and runs there. I'd sent an email to cummins and asked what temps to expect and they sent me an email saying that 225* is ok. I'm old school and this seems high. When I got home I let the truck Idle for awhile to cool down, and it went down to 190*. Clutch fan seems to be working fine. So, any info from your experiences would be great. By the way, the four day weekend was great. The Cyclone was wonderful. No problems. And very comfortable. I've done many of the tips I've pickup up from this forum in advance, and it made for a pleasent experience. This is my first experience pulling this large a 5th wheel with such a big frontal area. Used to have a motor home.

Thanks all for any info,


07-25-2006, 01:38 PM
Because your cooling system is under (I'm guessing) 15 pounds of pressure, 225 is fine for coolant temp. You would probably be safe up to 240 for a short haul. Another thing you have to watch is your transmission temperature. I don't know about Dodge, but Allison is 275. Above that, you are looking for trouble.


07-25-2006, 01:54 PM
The CTD 2005, the thermostat is set at 190 degrees F. That is why the normal operating point is at 190. During heavy loads, my will climb to 215 degrees F. Some people have said you can replace the stock thermostat with a pre 1999. These thermostats were a 180 degree F stat. Do you have a EGT gauge? If not you should invest in one. It sounds like your temps would be very high. Preturbo readings should not exceed 1350 degrees for the CTD. Also, I monitor oil temperature, this will track the same as coolant temp.

07-25-2006, 06:49 PM
Once my Cummins comes up to temp at about 190 it rarely moves. Once in a while temp will climb to slightly over the 200 mark..Now all I have is the stock guage where the first mark is 140 , the next is 200, and the last is 245 marked in red..All this will tell you is that there is no great increase or decrease in temps..

07-25-2006, 09:19 PM
We just got back from the Grand Canyon and Las Vegas, on the way there we went up I-40 from Winslow to Flagstaff where temps outside were 110 (nearer the Winslow end) and there is a fairly steady climb to get up to Flagstaff (8000 ft?). Engine temp was consistently 215-ish occassionaly getting to 220. I was probably doing 55-60 up the hill. From the Grand Canyon to Las Vegas we went through Laughlin, NV and temps were 112-115 outside and the engine temp was 220-225. There are a couple of pretty steep climbs from Kingman, AZ to Laughlin, NV. We came home through the Mohave in California, down to I-10 it was hotter outside, but most everything was downhill so engine temps were 210-215.

We were in Lake Charles last week and everything betwen here and there is flat and the temp outside in the upper 90's, engine temp stays around 200 doing 65-70.

I have the same setup as you with the Edge Juice with Attitude, I was told at install time the most important thing to watch is the EGT. Peaked a couple of times during these trips right at or below 1350, but never stayed there for very long.


bob hyder
07-25-2006, 10:16 PM
Thanks everyone for the quick responses. Well it seems like I don't have very much to worry about. The temps I had on my trip seem to be right in there with most everyone else. I do have a EGT gauge in my truck and it stayed below 1200* all the time except if I pushed the truck real hard then it hit 1250. I understand that 1350* and below is the safe area. I think the exhaust I put on helps keep it at safe levels. I do want to add a trans temp gauge. In the old days 275* and below where safe, but I've been out of mechanican professionally for about 13 years. Alot has changed since then.

Thanks all, Bob

07-26-2006, 04:33 PM
Hey Bob, do you remember what your boost pressure was running and max? I was wondering since you stated that you modified the exhaust. How about the intake, any mods? I am assuming you have done the tone ring modification. That mod really helps improve performance. I have a commander gauge so I defuel automatically on EGT, Coolant temp, fuel pressure and injection pressure setpoints.

bob hyder
07-27-2006, 12:29 AM
Diesel engineer,

The only intake mods have been to change the air cleaner to a high flow AFE air cleaner. After looking at the air box and where it picks up it's air, I don't feel that an after market cool air intake could do better. As for the turbo ring, I have mixed feelings about that one. I've read both pro's and con's about that. Might try it to see if it does any good. But to answer your question about the boost, I reach about 33 lbs. Well with in a safe level. And the edge juice defuels at my preset levels. Over boost, water temp, torque converter slipping, and EGT temps. I like to play it safe. I tried setting the juice at the stock setting and the water temps ran about the same, but with a noticeable decrease in performance. I'm starting to feel that it is normal to be running above 200* when pulling a heavy load. Any imput would be great.

Thanks Bob

07-27-2006, 03:40 PM
I found that a little above 215 is normal with the CTD. I have added a drop tube off the bottom of the stock air cleaner box. I was able to add an 5 inch tube down to a point below the bumper. This way I draw in the cool / cold air and no the hot engine air. It cost me just my time and was a good fix. The tone ring also was a low cost change, with great performance gains. I believe the stock setup will develop 35 psi boost. I know I can with a 5 inch exhaust and this intake mod go above that number with ease.