Greetings,

I've had my '03 SC 4x4 since December...had a few questions to tap the knowlege well.

Climate control:
It was freezing when I took delivery, so its been heat on all winter.
I recently wanted some outside March air to vent the cab...so I used the "Panel/Floor" switch and set the thermostat to "blue" (cool)
~~~ The air coming in was MUCH cooler than the outside air temp...(My ?) does this setting cause the AC compressor to activate??
I was listening for the clutch to kick in, but never heard it...
(I did not have it set to "AC"...or "MAX-AC")
All I wanted was some outside air to come in....any clues or hints?
When I take a long trip, I want to have the compressor completely idle during those nice weather rides.

My truck has a harmonic "vibration" that occurs about the first five miles of morning commute. At stoplights waiting, and at highway speeds, a rhythmic surge goes through the truck..then seems to surpass as it warms up. Any hints?

Does anyone have any ideas to increase the fuel economy?
Mine has the 3.73:1 rear, and is about 1600 rpm at 55mph.
I can seem to get more than 14/15 mpg from my truck...and I drive with an egg on the pedal, about 98% commuting over the highway.

Overall, I love it.... I gave up my 1986 F150,...(No AC!)
I found it a good home..

DN
2003 XLT F150 SuperCrew 4X4, 5.4, 3.73LS Highland Green/Beige, Beige cloth

 

The air cond. is engaged in all settings except FLOOR and PANEL when the temp. is above 43 degrees.
Mileage is normal. You will have to try some mods to improve fuel economy.

 

Thanks for the information.

I've replaced my share of AC clutches...avoiding those settings
will help the longevity...hopefully.

I honestly don't know why the compressor would engage in
any setting other than AC or MAX AC.
I'm sure few people are aware of this fact.
I don't like my engine working any harder than it has to.

Thanks again,
Dave

 

Thats what I wondered when I bought my truck. The <a href="http://motorhaven.autoanything.com/">owners manual</a> claims the air cond. is engaged in all those other settings for customer comfort or convience.

 

The a/c runs in the other settings to dehumidify the air in the cab.

 

I knew there was reasoning for Ford's design in that "comfort/convenience" realm.

I'm guessing that it kicks on regardless of the thermostat setting?? (warm or cold)

These are all parts of getting to know my new truck.
i.e. what makes it run best, and at what settings.
tbt, My main concern is getting better fuel economy, and an AC compressor robbing me of 15/20 horsepower is what I seek to avoid.

True, I'll run the AC on hot days, but I don't want it running
when the temps are just moderate.

Any clues as to this "vibration" ~~ ?

Thanks again
DN

 

Yes the a/c runs whether the heater is on hot or cold. It cycles though.....the compressor isn't on all the time like on an old system. It does this through pressure switches. I'm not sure how much power or mileage difference you'd see if you had the a/c never turning on but I doubt it would be much and I'd rather be comfortable even if it cost me a few cents.
My wife's Exploder has a vibration when it is cold too and I think it's the exhaust. I can hear that the tone is a bit different when it's cold and resonating. I haven't looked into it anymore as it goes away after a few minutes. It seems that maybe once everything has warmed up and the metal expands a bit something must tighten up and the noise goes away. Possibly a baffle in the muffler? One day maybe I'll look into it more.

 

I just scoured my 2003 <a href="http://motorhaven.autoanything.com/">owners manual</a>, and it makes little
reference to the actual physical opreation of the AC compressor.
I may have to dig deeper into a <a href="http://motorhaven.autoanything.com/">service manual</a> if I need more info..
(But thanks for what you all have provided)
If adjusting my comfort habits through simple control manipulation
can be acheived and save me even ONE mpg, I'll do it.
On a vehicle thats only getting 14/15 anyway, its worth educating myself.
Ford has a habit of creating their "comfort at any cost" philosophy, but at almost $2.00 a gallon, this helps!
Thanks for your take on the vibration...its hard to isolate.

DN

 

Daven,

My 02 Screw was getting about 16.5 mpg when new. After about 10000 miles the mileage started to improve. I recently got 17.8 on a short trip.

Remember though, you have a 4x4 pickup weighihg about 5300 pounds, with a 300 hp v8, running through 3.73 gears. Your mileage will never be great.

Great truck though. I love my 02.

 

I am very sure the 5.4L is 260hp, not 300 as stated above, am i wrong?

 

I believe the 03 has 300 hp with the new 3 valve heads. Although I have been wrong once this year already.

 

All I've ever read is that the (new) 2004 has the new 300hp 5.4.... at no point have I ever read about my engine (a 2003 5.4) having anything other than the 260 horsepower rating.

Popular Mechanics has a good article about Ford doing this to maintain a more competitive base with the new 2004 Nissan TITAN, which is their answer to the full-size truck market. That model (available only as an extended cab automatic) will have a 340 hp V8, if my memory serves.


...pass the rice.