Haulin_in_Dixie

A little info on the fan clutch. My radiator is spotless, engine runs cool, never goes above the middle mark regardless of the load or temperature. When I replaced the fan clutch, I replaced the fan with a 12 valve fan which has larger blades and make more noise. If I run without the air on it will come on for a minute when first starting then shut down. It won't come on again even loaded heavy pulling a hill at 95 degrees. But turn the air on and it runs almost constantly till I get to 70 mph or so and then it shuts down only to turn on again at the first slight grade.

With high humidity my air is costing me at least one mpg. It is more affected by humidity than temperature. 80 percent humidity at night at 75 degrees outside will keep the fan on almost constant. Temps in the high 80's with low humidity is much easier on the fan usage. The fan is a real loss for mpg. I have been thinking of one of the older Peterbuilt deals with the coil on the roof with an electric fan on it to keep the heat away from the radiator. Of course my truck is a work truck and the mileage is important. It is a meal on each tank of fuel.

cuminvsstrokin

Well fellas, I found out why my fuel mileage is so shotty, I just got my truck out of the shop for new lp and ip, Well the IP is already going out, my truck is getting btw 12-15 mpg and sometimes it is hard starting, Talked to my trusted old buddies at Cummins and they told me that more than likely the problem will only get worse and that inside the IP is a pressure disc which builds fuel pressure frm the lp, and it most likely damage, so now 500 miles from spending 1700 bucks and a day of down time, I'm gonna be lucky to make my way home of 400 miles knowing that any minute that my IP is gonna go out again and i'm on vacation, boy can i pick it or what, called the shop who put the ip on and they told me to bring it back in and the will try and get another ip put right away.

NMotion

Anybody know how big the fuel tank is on a 03 crew 2500 short bed cummins? From the time the light comes on and it says 0 miles till empty I can get about 30 gallons in it. How big is the reserve?

B.A.Ram

Aight sorry to bring this one back. With the edge box on or off, I get 350 miles on a tank of fuel. When I fill up I put 24 gallons in so it is in the 14-15 mpg range. I pulled the IAT and it wasn't very dirty but I cleaned it anyways. My egt's w/out the edge are 1000 pegged out with 21 lbs of max boost. Not sure if these are normal. The back of the radiator is clean. I haven't changed the thermostat but I know the fan has a decent amount of resistance on it and constantly runs. Even with the fan running my truck will still let the needle notch above 190-205 or so. Is it my cooling system that is eating my fuel mileage?

Cyborrg

I think you, like me, have a 30 gal tank. You might want to fill up a little sooner.

OUTDOORSMAN

baram, you say the back of the radiator is clean, did you actually use pressured water and blow through the radiator to make sure it is clean inside? did you replace your antifreeze? a thermostat is cheap, replace it. how about between the radiator and cooler? is it clean there? tire pressure? check it and make sure all tires are in good operating range. soft tires eat fuel.

Mopar1973man

Your EGT's temps and boost numbers are totally normal for stock engine.
Cruising at about 65 MPH should get you about 800*F EGT Roughly about 5-7 PSI boost on flat ground at about 4K feet from sea level.

You might think about changing the antifreeze and the thermostat... They also have 180*F thermostats... I drain and flush my cooling system every other year. My fan rarely comes on and I never seen temps above 192-195*F (Needle width over 190*)

B.A.Ram

I had the breather re-located by the dealer and when they did they they cleaned the radiator out. I will flush the coolant and change the thermo-stat and see if that helps. How much air pressure do you guys run in your tires?

kipo

B.A. Ram:

i too had problems overheating in the TX heat. my needle would creeep up above 190 daily even with little driving. i changed the t stat and fluid now it fluctuates below 190 quite frequent. you can hear the fan come on from time to time but you have to listen for it, we checked and it has some resistance so i believe its' good. i too have always wondered about the electric fans. my brother has a black majic on his 351 ford and likes it.

CHECK the radiator. we almost replaced a $177 fan clutch on my girlfriends truck because her a/c wasn't cooling very good. we found out that it wasn't moving enough air through the condensor. (bad fan clutch) WRONG!!! she never washes her motor, therefore she had oil and dirt and a lot of build-up that clogged her radiator. it looked clean but was very dirty inside. now the a/c works a lot better. we also replaced her t stat and did a flush like i did. she averages about 21-22 miles per gallon on a so swb 2wd. i on the other hand only get about 375-400 miles out of 26 gallons. i think the main thing that hurts us in gas mileage is the 4 wheel drive, and DRW for some. i always run max pressure in my tires. a little bumpy but the way to go.

just my .02

i think we need to do a little research on the elctric fan. my only concern with electric is reliablility. the main problem my brother had was with the connections going bad (loosening, ect. but he never soldered them like i told him to) wheelin, or extreme duty might not be strong enough for a plastic fan??? but it might fit inside the oem shroud and be better protected???

Wantdiesel?

My '03 Q.C. short box has a 34 Gallon Tank

Marine

I fill up at about 1/4 tank. Usually put about 25 gallons and go anywhere from 420 miles to 480 miles. 19.2 - 16.8 mpg

Mike

B.A.Ram

Marine I don't know how you get those numbers. I just got my thermo from the dodge house and will change it this weekend(it was $38... ). Will wash out the back of the radiator even though it appears clean, and am going to flush the radiator. Well see if that makes a difference. Oh and with my edge ez back in I can tap 28-30lbs of boost but still only 1000 egt's. Oh and if the inside of your front tires are wearing where it looks like a roller coaster(one lug high and one lower) do you think it is balljoints?

Marine

I bought my Thermostat from a Kenworth dealer and it was 17.00 or so. I just drained the Rad and Block, and put in Rotella pre-mix. I can get to 900 deg Post Turbo when really lugging the engine, but that's it.
I think you should look at your shocks. My tires started doing this, so I replaced the shocks and got an alignment. Seems good now.
Best mileage I did was 22 going from Victorville, CA to San Clemente, CA, on I-15.

Mike

wildcargo

I have not had my truck long but I have bin checking the milage and I have gotten 19.5 hiway and city combined and 16.5 city. on the combined 350 hiway and 130 city miles That is with me and wife and no load. Well I am a load if you ask the wife. I towed the race car with it but it is only 60 miles to and from the track and with 200 mileson that tank I still got 16mpg, car and traler and gear about 5000#. So far I am verry happy with my truck I baught it used with 39,000 miles on it 2500 quad cab long bed 4x4. I was towing with a 94 dakota 4x4 short bed , a real adventure.

Rodram2002

B.A.Ram,
Sorry to hear about this. Try this on your next tank of fuel. Shift at about 1600-1700 rpm's and try not to go over 10 lbs of boost. this is how I drive in the city and I get 18-19mpg. Look in my sig. to see what I have. The injectors give me better mpg, but I still got 17-18 mpg befor them. Hope this helps some.