Watching my gas gauge go down consistently

[DaddiGrouch]

idler pulley wobbles very badly, and the fan blade itself has many cracks between each blade. I have the 4.0 OHV engine, she has so much power when I began driving her gave her a nice proper tune up (had the original plug in cylinder 3 from its difficulty to get too) and have since then flushed the entire cooling system and that's a thread post and story on its own. However, since the cooling system replacement the idler pulley sounds are much worse and i can literally move it back and forth so im threading on a thin needle right now I know. I'm curious as to what is burning my gas so badly, any suggestions? the idler pulley is making the fan blade seem wobbly, I originally thought that it was the water pump pulley, However once I seen the idler pulley I now know that the belt is wobbling back and forth over the fan assembly pulley.

Also a few questions of mine- Would a bad idler cause worse gas mileage? As well with a bad fan blade?
My theory is that it would given the stress on the engine that it is being given. It is working much harder than it should. I originally post on Reddit with all of my questions and concerns because all posts I see from this website or the next are posts from 10+ years ago. So I may be postin gthis for no reason. I hope not! Show me this is still very much active

 

[Roert42]

What’s the MPG?

the 4.0 is kinda a pig without the manual trans.

Vacuum leaks and worn out O2 sensors will also cause poor fuel economy.

Maybe you have a hole in the gas tank.

 

[DaddiGrouch]

What’s the MPG?

the 4.0 is kinda a pig with the manual trans.

Vacuum leaks and worn out O2 sensors will also cause poor fuel economy.

Maybe you have a hole in the gas tank.

I wouldn’t be able to give you an exact MPG however I can tell you that I could take a 90 mile drive and it not even budge, so normally I was getting beautiful gas mileage. I normally drive a 88 350 small block man, and she EATS gas. So that’s what I compare my gas too, it’s MUCH better than the Chevy. However now like I said in the post I can see it drop significantly, and normally I would take that kind of drive and it be perfectly fine, may use half a quarter on a 100 mile drive. (I live in hardinsburg Ky, and I drive to Owensboro to shop, which is 41 miles not including the stop and go there, and the drive back and I might get a quarter gone or just half a quarter) now I’m driving 20 miles and she’s eating a quarter

 

[DaddiGrouch]

What’s the MPG?

the 4.0 is kinda a pig with the manual trans.

Vacuum leaks and worn out O2 sensors will also cause poor fuel economy.

Maybe you have a hole in the gas tank.

only leaks would be from oil, and I have sat there and watched her for some time right after drives and such

 

[DaddiGrouch]

What’s the MPG?

the 4.0 is kinda a pig with the manual trans.

Vacuum leaks and worn out O2 sensors will also cause poor fuel economy.

Maybe you have a hole in the gas tank.

no codes as well, vacuum leaks would be very likely and I wouldn’t even know where to start but spray everything with starter fluid.

 

[rusty ol ranger]

A bad idler pulley isnt gonna cause MPG loss.

Check engine on? Thats a place to start.

Vacuum leaks will make the engine run lean, which will then make the o2's dump fuel to compensate.

You *sure* your MPG has gone down and its not a gauge/sender/float issue? My ranger will say empty when theres 1/4 tankish left. Its about a 1/4 tank off through the whole sweep

 

[RonD]

Change O2 sensors every 12 years or 100k miles, period

They are the only sensors that wear out on a time/miles line
They use a chemical reaction to detect oxygen in the exhaust, and this reaction generates a voltage
As the chemicals are used up the voltage goes down and that causes lower MPG
You can use O2s for 20+ years, but you could have bought 10+ new O2s with the money you waste in lower MPG, lol, until you have to change them when you do get codes


We all know "Car" Batteries wear out in 4 to 7 years because their chemical reactions can no longer hold a charge
Same type of thing with O2s
Just change them

 

[DaddiGrouch]

A bad idler pulley isnt gonna cause MPG loss.

Check engine on? Thats a place to start.

Vacuum leaks will make the engine run lean, which will then make the o2's dump fuel to compensate.

You *sure* your MPG has gone down and its not a gauge/sender/float issue? My ranger will say empty when theres 1/4 tankish left. Its about a 1/4 tank off through the whole sweep

I need to find all of the common vacuum leaks for the truck, everything is stock besides what I’ve replaced so far, poor ole ball joints need some attention but no time. She starts acting up big time whenever it gets to a quarter and below, harder for take off, gas pedal gets more stiff the faster I go, likes to big jump during take off, I know that wasn’t in complete order and that it falls in line with the first point, the check engine light would not be on. Fortunately I know it works and is accurate, I tested it by disconnecting the MAF sensor and it indeed popped the code and went away fairly quickly when plugged back in. (I did disconnect the battery before doing so and plugging it in)

 

[DaddiGrouch]

Change O2 sensors every 12 years or 100k miles, period

They are the only sensors that wear out on a time/miles line
They use a chemical reaction to detect oxygen in the exhaust, and this reaction generates a voltage
As the chemicals are used up the voltage goes down and that causes lower MPG
You can use O2s for 20+ years, but you could have bought 10+ new O2s with the money you waste in lower MPG, lol, until you have to change them when you do get codes


We all know "Car" Batteries wear out in 4 to 7 years because their chemical reactions can no longer hold a charge
Same type of thing with O2s
Just change them

what’s your source? I only ask because I want to know if that’s throughout all vehicles, my lady has a 2012 Mazda 3 skyactiv, she has 220k miles and daily drives it. I will most definitely change those pocket breakers because I also have the original O2s and I’m just now reaching 100k miles

 

[DaddiGrouch]

what’s your source? I only ask because I want to know if that’s throughout all vehicles, my lady has a 2012 Mazda 3 skyactiv, she has 220k miles and daily drives it. I will most definitely change those pocket breakers because I also have the original O2s and I’m just now reaching 100k miles

89k original miles, it has all of the stock parts, every part I’ve taken off has been ford stamped besides the battery, and it even has the original master cylinder recall problem occurring. Many more examples pointing to it being that exact mileage

 

[RonD]

O2 sensor manufacturers recommend 50k-60k miles but they like to sell O2 sensors, so grain of salt

Personal experience has been 10-12years or 90k-100k miles and you will see a SMALL MPG increase, so haven't lost much money in wasted fuel

 

[DaddiGrouch]

O2 sensor manufacturers recommend 50k-60k miles but they like to sell O2 sensors, so grain of salt

Personal experience has been 10-12years or 90k-100k miles and you will see a SMALL MPG increase, so haven't lost much money in wasted fuel

Then that’s it man something went off bad, we got hit with winter cold and that’s when it really took off, warm days man beautiful gas mileage. I was slightly overheating, (didn’t notice because it was since I got the truck) brown, murky, rusty, coolant water with a thick inch of black stuff at the bottom of the radiator, flushed quite a few times, so much so I can feel the bottom of the radiator now! After I did the last flush, shoved the water hose in the lower radiator hose, ran the motor, shiiiiiiiit gas mileage. Mind you the thermostat housing and thermostat were indeed out of it, she also sounds like shit and that’s the day when I noticed the idler pulley was real bad.

 

[rusty ol ranger]

Then that’s it man something went off bad, we got hit with winter cold and that’s when it really took off, warm days man beautiful gas mileage. I was slightly overheating, (didn’t notice because it was since I got the truck) brown, murky, rusty, coolant water with a thick inch of black stuff at the bottom of the radiator, flushed quite a few times, so much so I can feel the bottom of the radiator now! After I did the last flush, shoved the water hose in the lower radiator hose, ran the motor, shiiiiiiiit gas mileage. Mind you the thermostat housing and thermostat were indeed out of it, she also sounds like shit and that’s the day when I noticed the idler pulley was real bad.

Might wanna replace the coolant temp sensor. Or atleast pull it out and make sure the probe isnt covered in shit

 

[00t444e]

I wouldn’t be able to give you an exact MPG however I can tell you that I could take a 90 mile drive and it not even budge, so normally I was getting beautiful gas mileage. I normally drive a 88 350 small block man, and she EATS gas. So that’s what I compare my gas too, it’s MUCH better than the Chevy. However now like I said in the post I can see it drop significantly, and normally I would take that kind of drive and it be perfectly fine, may use half a quarter on a 100 mile drive. (I live in hardinsburg Ky, and I drive to Owensboro to shop, which is 41 miles not including the stop and go there, and the drive back and I might get a quarter gone or just half a quarter) now I’m driving 20 miles and she’s eating a quarter

Going by the fuel guage isn't accurate, need hand calculated MPG numbers.