Getting bad gas mileage

Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 2003 FORD ESCAPE
  • 3.0L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 192,463 MILES
Hello, my car getting bad gas mileage about 13-14 mpg.
new: spark plugs , coils, filters, fuel filter, no check engine light. (Car was getting about 17-18 mpg)
shrift1 (%) -0.8
longft1(%) -10.9
shrift2(%) -3.1
longft2(%) -8.6
rpm 756
sparkdv(C) 10
Thursday, January 24th, 2019 AT 9:50 AM

31 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning,

There are so many factors for fuel mileage.

Driving habits are the most important.

Tires. The tires need to be properly inflated and check regularly.

Alignment. Front end alignment is critical for the car rolling free.

Brakes. Make sure they are not hanging up. Have them checked regularly.

Filters. Make sure the air and fuel filters are changed every year.

Transmission. Make sure the shift points have not changed.

Roy
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Thursday, January 24th, 2019 AT 10:56 AM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
I have had this car about eleven years. Every thing is changed always at time, but now it has bad mileage, new spark plugs coils is installed, filters. Only code sometimes show is p0705. No check engine overdrive light. Car drives good but getting bad mileage. Tires are balanced, alignment is done. I saw that longft and srift is always in negative, car sometimes idle.
Shrift1 (%) -0.8
longft1(%) -10.9
shrift2(%) -3.1
longft2(%) -8.6
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Thursday, January 24th, 2019 AT 11:03 AM
Tiny
ASEMASTER6371
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The long terms could be from either the engine running a little rich, possibly from an air filter, or the sensors are worn out.

The 705 is for the transmission range sensor not reading correctly. That would have nothing to do with the mileage issue.

Timing chains are the other thought. Have you ever had them replaced?

Roy
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Thursday, January 24th, 2019 AT 11:19 AM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
No, never. Which sensor may be worn out?
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Thursday, January 24th, 2019 AT 11:23 AM
Tiny
ASEMASTER6371
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Oxygen sensors.

The timing chain controls valve timing. If the chains are worn, that timing will change and you will get less mileage.

Roy
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Thursday, January 24th, 2019 AT 11:26 AM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
If timing chains are bad it should have sound? Engine working fine no bad sounds
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Thursday, January 24th, 2019 AT 11:33 AM
Tiny
ASEMASTER6371
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No, not at all. They slack off and you cannot hear that at all.

Roy
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Thursday, January 24th, 2019 AT 12:02 PM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
Thank for answer. How can I check if chain went bad?
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Thursday, January 24th, 2019 AT 12:03 PM
Tiny
ASEMASTER6371
  • MECHANIC
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You would need to do a compression test and compare the readings to new.

https://www.2carpros.com/articles/how-to-test-engine-compression

Then the cover for the chains should be removed to inspect. That is a big job and if you are going to go that far, then you might as well replace it.

Roy
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Thursday, January 24th, 2019 AT 12:10 PM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
Our compression test was done about three month ago mechanic sad that compression was good (like new one).
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Thursday, January 24th, 2019 AT 12:12 PM
Tiny
ASEMASTER6371
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Okay, that was three3 months ago and this is now and you have different mileage.

Roy
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Thursday, January 24th, 2019 AT 12:15 PM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
Mileage from the test changed with 200 miles, I will check that again.
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Thursday, January 24th, 2019 AT 12:16 PM
Tiny
ASEMASTER6371
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Okay, sounds like a plan.

Roy
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Thursday, January 24th, 2019 AT 12:25 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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I have seen MAF cause this problem even though the numbers are kind of where they should be the sensor shows less air than what is entering the engine. I would replace it will new. here is a guide and diagrams below:

https://www.2carpros.com/articles/how-to-replace-a-mass-air-flow-sensor-maf

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
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Friday, January 25th, 2019 AT 1:44 PM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
Installed new maf sensor, also compression test was done "perfect numbers"
now showing
Shrift1 (%) -7.8
longft1(%) -13.3
shrift2(%) -7.8
longft2(%) -8.6
maybe air leack? Car drives good
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Saturday, February 2nd, 2019 AT 10:28 AM
Tiny
ASEMASTER6371
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The long term trims indicate it is running rich. They should be much closer to 0.

Have you had the injectors professionally cleaned? Additives have no effect on cleaning.

Roy
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Saturday, February 2nd, 2019 AT 2:28 PM
Tiny
GIGISULAMANIDZE1
  • MEMBER
  • 88 POSTS
Update:
injectors professionally cleaned, new air intake gaskets, car runs better. Now showing this :
Shrift1 (%) -2.8
longft1(%) -5.5
shrift2(%) -3.4
longft2(%) -5.5
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Saturday, February 16th, 2019 AT 10:26 AM
Tiny
ASEMASTER6371
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Much better.

Is the light off now?

Roy
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Saturday, February 16th, 2019 AT 11:35 AM
Tiny
GIGISULAMANIDZE1
  • MEMBER
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Check engine light was off, better gas mileage now. Next week I will try smoke test.
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Saturday, February 16th, 2019 AT 11:39 AM
Tiny
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Sounds good.

Roy
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Saturday, February 16th, 2019 AT 11:41 AM

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