Blazer Forum Blazer Forum  
Chevy Blazer Forums
Chevrolet Blazer Forums
Chevrolet Blazer Blazer Forum   Classifieds   Photo Gallery   Search   Contact BF   Sponsors
  Blazer News   Member List   Forum FAQ   Timeslips   Recalls   TSBs   Calendars   Register   Login  

Horrible Gas Mileage on my New 2004 4.3ltr. Help!

  Printable Version
Blazer Forums >> Mechanical & Maintenance >> General Tech Help >> 2nd Gen (1995-2005) Tech >> Horrible Gas Mileage on my New 2004 4.3ltr. Help! Page: [1] 2   next >   >>
Login
Message << Older Topic   Newer Topic >>
Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 12:31:58 PM   
komodopb

 

Posts: 13
Joined: 3/19/2007
Status: offline
Well I just bought a 2004 2 door 4.3 ltr Blazer last month that has an automatic transmission with 26k miles on it. After the first week, I noticed I was getting horrible gas mileage so I filled the tank a couple of times, tracked exact miles, divided by how many gallons I put in and the result is my car gets 10.7 mpg - far below the 16/19 miles as stated. Now I know this topic has been addressed before, but I haven't seen anyone with this low of gas mileage, especially on a car that is practically brand new. My question is, besides the front axle not disingaging (which isn't my problem - I checked) and 02 sensors, could the previous owner have changed any settings to improve performance but ruined the efficiency? I know this truck was used for towing so maybe he set it up for more power? If so, how can I check for this, or could it be another problem?

Any help would be greatly appreciated cause this is killing me.

Thanks!
Post #: 1
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 12:48:01 PM   
supramacist

 

Posts: 13
Joined: 3/19/2007
Status: offline
You could have diagnostics ran on the auto.  It's a 4.3 liter and automatic so it's bound to be a gas hog.

It's a 2004 with only 26k on it.  Sounds like you may have found out why the previous owner was selling it.  He couldn't afford the gas.  However, there are a few things I would do to improve the performance and gas mileage issue.

The first thing I would do is a full service tune up.  You may surprised by how much this gets overlooked and how many gremlins letting this pass can cause your auto to have.  From the plugs to the air filter.  Full service.  Your plugs not being gapped propperly could cause it to suck gas just like a nasty air filter will.

Last but not least.  Run your tank as close to E as you can stand it.  Get 1 qt. of automatic tranny fluid and a funnel.  Insert this 1 qt. into the close to empty gas tank.  Fill up with premium.  Now this only works if your'e fuel injected and I am sure you are. 

What the tranny fluid in the gas tank does is makes you 2 cycle.  It's going to clean **** out of the injectors as well as lubricate the entire system.  But the beautifull thing is with the addition of premium gas to this equation.  Your engine will burn more hot than normal, clean out engine gunk or residue of any kind.  Lubricate your internals, make you run more smooth, it also improves gas mileage.

I do this to all of my auto's.  If you nut up and try this 1 tactic after you have everything worked out, you'll not only be thanking me, but you will pass it on as well.

Good Luck

(in reply to komodopb)
Post #: 2
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 1:25:02 PM   
fernandoh

 

Posts: 51
Joined: 12/29/2006
Status: offline
I'm gettin 13 in heavy traffic and 18..... in the 80 miles hwy. I believe the figures are correct for the 2000 4 doors, 4.3 auto.
Suggested: 195º thermostat (maybe is clogged open or too low in temperature: more fuel to heat it up), check the rad fan always on (carefully, mechanical effort and lo temp)), a vacuum leak somewhere (poor gas air ratio and the PCM is trying to fix that), the MAF wires dirty... and your right foot.

(in reply to supramacist)
Post #: 3
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 2:16:42 PM   
pittguy25

 

Posts: 1
Joined: 3/8/2007
Status: offline
Could you tell me how high octane gas will burn hotter?

quote:

ORIGINAL: supramacist

You could have diagnostics ran on the auto.  It's a 4.3 liter and automatic so it's bound to be a gas hog.

It's a 2004 with only 26k on it.  Sounds like you may have found out why the previous owner was selling it.  He couldn't afford the gas.  However, there are a few things I would do to improve the performance and gas mileage issue.

The first thing I would do is a full service tune up.  You may surprised by how much this gets overlooked and how many gremlins letting this pass can cause your auto to have.  From the plugs to the air filter.  Full service.  Your plugs not being gapped propperly could cause it to suck gas just like a nasty air filter will.

Last but not least.  Run your tank as close to E as you can stand it.  Get 1 qt. of automatic tranny fluid and a funnel.  Insert this 1 qt. into the close to empty gas tank.  Fill up with premium.  Now this only works if your'e fuel injected and I am sure you are. 

What the tranny fluid in the gas tank does is makes you 2 cycle.  It's going to clean **** out of the injectors as well as lubricate the entire system.  But the beautifull thing is with the addition of premium gas to this equation.  Your engine will burn more hot than normal, clean out engine gunk or residue of any kind.  Lubricate your internals, make you run more smooth, it also improves gas mileage.

I do this to all of my auto's.  If you nut up and try this 1 tactic after you have everything worked out, you'll not only be thanking me, but you will pass it on as well.

Good Luck

(in reply to supramacist)
Post #: 4
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 2:53:48 PM   
USMaverick101

 

Posts: 130
Joined: 9/21/2006
Status: offline
I've never in my life heard of putting a quart of tranny fluid as a fuel injector cleaner. Can anyone back this up?  I would try seafoam through the intake and in the gas tank. It worked very slightly for me, but it was better than nothing. I still get 10mpg on my 92 4.3l Vortec
quote:

ORIGINAL: supramacist

You could have diagnostics ran on the auto.  It's a 4.3 liter and automatic so it's bound to be a gas hog.

It's a 2004 with only 26k on it.  Sounds like you may have found out why the previous owner was selling it.  He couldn't afford the gas.  However, there are a few things I would do to improve the performance and gas mileage issue.

The first thing I would do is a full service tune up.  You may surprised by how much this gets overlooked and how many gremlins letting this pass can cause your auto to have.  From the plugs to the air filter.  Full service.  Your plugs not being gapped propperly could cause it to suck gas just like a nasty air filter will.

Last but not least.  Run your tank as close to E as you can stand it.  Get 1 qt. of automatic tranny fluid and a funnel.  Insert this 1 qt. into the close to empty gas tank.  Fill up with premium.  Now this only works if your'e fuel injected and I am sure you are. 

What the tranny fluid in the gas tank does is makes you 2 cycle.  It's going to clean **** out of the injectors as well as lubricate the entire system.  But the beautifull thing is with the addition of premium gas to this equation.  Your engine will burn more hot than normal, clean out engine gunk or residue of any kind.  Lubricate your internals, make you run more smooth, it also improves gas mileage.

I do this to all of my auto's.  If you nut up and try this 1 tactic after you have everything worked out, you'll not only be thanking me, but you will pass it on as well.

Good Luck


_____________________________

1992 Chevy s10 Blazer 4.3 Vortec CPI
98,500 miles, Tahoe LT edition 4dr 4x4


(in reply to supramacist)
Post #: 5
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 3:42:54 PM   
swartlkk


Posts: 14473
Joined: 5/1/2005
From: Waterloo, NY
Status: offline
swartlkk's photo gallery
Please lets not get off topic here.  The topic is trying to help the author find the reason behind his low fuel mileage.

I know on my truck, it is finicky about where I get gas.  It absolutely hates fuel from the local Walmart (can't think of the brand right now) and it will drop 4mpg just using that fuel.  Fill up at either the local Mobil or at the new Kinney station and I gain that mileage right back.  So maybe try a few tanks from a different gas station and see how it reacts.

As a start, I would also like to recommend that you try some Iso Heat in the tank to check and see if maybe you have gotten some water into the tank that is causing issues.  Run it through a few tanks.

I would check over all of the ignition components.  At only 26k miles, there should be nothing wrong with any of these components, but manufacturing as it is these days, it could have been a factory flaw.  The wires can be checked at night with a spray bottle of water.  Just mist down the wires and surrounding surfaces and look for sparks jumping around.  I would also pull the plugs to check their condition and verify the gap.

Check/replace the air filter.  If the previous owner had installed a K&N or other oiled aftermarket air filter, the oil could have coated the MAF sensor, causing all sorts of issues, one of which is poor fuel mileage.  You would want to clean the MAF sensor (run a search, it has been discussed before).

Now, I have never heard of putting auto trans fluid into the gas and would highly suggest you do not.  With the plethora of quality injector cleaners on the market (Chevron w/ Techron is what I use on a routine basis), why go with such an unknown. 

Higher octane does not mean higher combustion temperatures.  Higher octane simply means that a fuel can withstand higher pressures before spontaneous combustion occurs (pre-detonation).  The content of say ethanol in the fuel will mean higher combustion temperatures due to the burning properties of ethanol vs gasoline.  And ethanol is a very good cleaner of fuel systems.  That is primarily where it gets its bad rep from.  It will clean a fuel system well enough that the first few tank fulls may result in very poor mileage, however, it is just the varnish that was left behind by gasoline that is being dissolved by the ethanol that causes this.  But again, that is a topic for another thread.

But before you do any of this, get some input from the dealership you purchased it from and explain to them that it is not running properly.  10mpg is not proper.  At close to 3 years old and less than 36k miles, it should still be under the GM warranty.

< Message edited by swartlkk -- 3/19/2007 3:44:54 PM >


_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to pittguy25)
Post #: 6
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 4:27:02 PM   
komodopb

 

Posts: 13
Joined: 3/19/2007
Status: offline
Thanks for all of the suggestions. After doing some more searches on this forum and seeing that I'm way off target, I made an appointment with the dealer for Wednesday - thankfullly, I purchased the GM extended warrenty. I'm also going to pop the hood tonight and see if I have a K&N filter & check the MAF Sensor.

As a side note, I've been filling the truck only with Mobile or Hess 87 octane and the results are the same. I'll re-post as soon as I find or get an answer. I just hope they don't give me the runaround that everything is fine and try to send me on my way.

Thanks!

(in reply to swartlkk)
Post #: 7
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 5:09:03 PM   
supramacist

 

Posts: 13
Joined: 3/19/2007
Status: offline
Cleaning the gunk out of your injectors unrestricts them and allows them to work propperly.  With an MSD dist cap and wires and iridium plugs, it just burns more hot.  92 octane burns more hot than 87.
Once you fine tune your combustion times with your spark times and your gas to air ratio, this is what I mean by hot.  I don't  really mean combustion temps.  Sorry for the slang on my part. 

As for the tranny fluid.  Try it.  The smoke you see is the carbon and other residue being burnt off.  Run the tank half way down and refuel.  With premium, you can use 87 oct. and still feel it working.  But the premium sets it off.  I tried sea foam in the gas tank.  it was alright, but the tranny fluid costs less and works better.  I tried marvel mystery oil in a pich on a otr trip.  It was about the same as sea foam.

Some of you chevy guys think different than the crowed I am used to.  But that's cool.  I can dig it if you cats can.

< Message edited by supramacist -- 3/19/2007 5:16:25 PM >

(in reply to komodopb)
Post #: 8
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 6:36:41 PM   
Zygoat


Posts: 214
Joined: 6/24/2006
Status: offline
Zygoat's photo gallery
it also might be possible that the guy before put lower gears in you said he used it for towing. that will keep your gas mileage down no matter what you do. just another idea.

(in reply to supramacist)
Post #: 9
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/19/2007 10:36:05 PM   
komodopb

 

Posts: 13
Joined: 3/19/2007
Status: offline
Very good point about the gears. What are the tell tale signs if they were changed? Lower RPMs?

(in reply to Zygoat)
Post #: 10
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 12:00:34 AM   
pilgrim


Posts: 192
Joined: 1/5/2006
Status: offline
I agree that your Blazer is definitely sub-par on mileage, and that going to the dealer is the best step. Since it's under warranty, get your money's worth!!

In a 4x4, the front and rear axles must run the same ratio or you'll blow up something when you engage 4WD. Chances are VERY slim that the previous owner changed anything, as it would mean changing both axle ratios. Much more logical for him to buy the ratio he wanted in the first place. However, the dealership can easily check this for you.

And if you want to clean your fuel injectors (although at 26K miles I can't imagine why) I echo the idea to buy Techron and run it through, not ATF.

With a car this new, I sincerely doubt that this has anything to do with any kind of deposits in the motor. It's much more likely to be something computer / electrical in nature.


_____________________________

*************
99 4WD Blazer, auto.
99 Jeep Cherokee Sport, auto.
Fort Collins, CO
*************

(in reply to komodopb)
Post #: 11
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 1:31:15 AM   
supramacist

 

Posts: 13
Joined: 3/19/2007
Status: offline
Tell tale signs of lowered gears.  Less gas mileage.  It's almost the same as shifting from 2 hi to 4 lo.
You still get the rpm's but less speed.  So it would be the same way in 2 hi.  Same rpm's..., different top end speed.

Hello techron...,  I have seen this brand.  What is it exactly you have added to your tank instead of my atf, cause that works well.  I would try this.  I wouldn't give someone 411 on a forum that I hadn't done and trust.  I agree that your'e probably right about the mileage being low and the afore stated mix.  I failed to take that into consideration before I posted.

(in reply to pilgrim)
Post #: 12
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 7:58:32 AM   
swartlkk


Posts: 14473
Joined: 5/1/2005
From: Waterloo, NY
Status: offline
swartlkk's photo gallery
As far as the gears go, what is your RPM at 60mph in OD?  My Bravada has 3.73 rear gear.  At 60mph with the TC locked up in OD, I'm running right around 1900RPM.  I also have the 235/70R15 tires which compounds things a bit more on my truck.


_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to supramacist)
Post #: 13
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 9:28:41 AM   
drperry


Posts: 3901
Joined: 1/12/2007
From: GP AB CA
Status: offline
drperry's photo gallery
Not to sound like an arse... But how hard are you pressing the gas pedal? I know a lot of people that complain about poor gas mileage on their trucks, but don't really notice they're stomping on the pedal...


Did the previous owner keep up on oil changes?

How's the transmission fluid?

Do you know what kind of loads the previous owner was towing?

You should be rated at 18/26 for your mileage... That's what mine is rated at, and from what I can find, there's no difference according to paper between the 5 speed and the auto...

10MPG is very bad... Is the truck still running factory sized tires? Are they at the right air pressure?

_____________________________


(in reply to swartlkk)
Post #: 14
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 9:39:28 AM   
swartlkk


Posts: 14473
Joined: 5/1/2005
From: Waterloo, NY
Status: offline
swartlkk's photo gallery
Even an '05 wasn't rated at 18/26.  Best I can find is 15/19...  But still, he is low. 

Heck, my Bonneville is only rated at 18/28.


< Message edited by swartlkk -- 3/20/2007 9:40:46 AM >


_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to drperry)
Post #: 15
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 11:19:30 AM   
komodopb

 

Posts: 13
Joined: 3/19/2007
Status: offline
quote:

ORIGINAL: drperry

Not to sound like an arse... But how hard are you pressing the gas pedal? I know a lot of people that complain about poor gas mileage on their trucks, but don't really notice they're stomping on the pedal...


At 10 miles per gallon, real light.

(in reply to drperry)
Post #: 16
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 11:20:12 AM   
Dabber


Posts: 375
Joined: 7/11/2006
Status: offline
Dabber's photo gallery
I find that with my truck when I first got it the milage was bad ( Not that bad) but could have been better. With nearly 40000km on it now I find that the gas goes a little farther. I think there is probably a 75 to 100 km difference in tanks now. Might not be much in miles to the gallon but it does seem to get a little better 

_____________________________

2005 Blazer 4X4

(in reply to swartlkk)
Post #: 17
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 12:27:07 PM   
USMaverick101

 

Posts: 130
Joined: 9/21/2006
Status: offline
I just put in something yesterday on my truck and am still yet to see if it works. It's called a Turbomag,...you clamp it on your fuel line right before the plenum. The magnet helps the flow of the fuel through your fuel line, supposedly. It was only like $6 on ebay so it was worth a shot. If you want,go ahead and try one, or wait a while so I can tell u if its working for me.

HOW DOES TURBOMAG WORK? Untreated Fuel molecules tend to “clump” together due to attraction between molecules with charges of opposite polarities. This causes an inefficient burn. As a result, your engine experiences loss of power, lower gas mileage and lots of carbon build-up. Turbomag’s powerful magnetic field causes these “clumps” of fuel molecules to be charged with a single polarity, thus they repel each other making the fuel disperse more efficiently causing more complete combustion and power production. Turbomag will actually remove the existing carbon build-up in your engine - this usually takes an average of 3 tanks full of gas, followed by a dramatic increase in gas mileage and horsepower.





Heres the link to the turbomag site,...http://www.myturbomagnet.com/index.html
Theyre a little bit more on the website, than on ebay. If you search on ebay, you'll probably find it for like $2 cheaper. Try it out, you got nothing to lose.


_____________________________

1992 Chevy s10 Blazer 4.3 Vortec CPI
98,500 miles, Tahoe LT edition 4dr 4x4


(in reply to Dabber)
Post #: 18
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 1:02:52 PM   
swartlkk


Posts: 14473
Joined: 5/1/2005
From: Waterloo, NY
Status: offline
swartlkk's photo gallery
snake oil...  Car & Driver as well as Motor Trend tested the most popular 'fuel savers' on the market and all of them are gimics and a few (tornado comes to mind) actually hurt performance  (the Federal Trade Commision does this testing as well).  Not to mention that those magnets, if close enough to a few of the sensors, may cause the CEL to illuminate with various sensor related problems.  Sorry to be the bearer of bad news...

Here's some lite reading for ya: FTC "Gas-Saving" Products


_____________________________

Kyle-

2004 Rainier
1970 Chevelle - Resto
1974 K5 Blazer - Resto

(in reply to USMaverick101)
Post #: 19
RE: Horrible Gas Mileage on my New 2004 4.3ltr. Help! - 3/20/2007 5:35:43 PM   
drperry


Posts: 3901
Joined: 1/12/2007
From: GP AB CA
Status: offline
drperry's photo gallery
quote:

ORIGINAL: swartlkk

Even an '05 wasn't rated at 18/26.  Best I can find is 15/19...  But still, he is low. 

Heck, my Bonneville is only rated at 18/28.



I've still got the window sticker, lol, I'll take a pic of it...



quote:

ORIGINAL: komodopb

quote:

ORIGINAL: drperry

Not to sound like an arse... But how hard are you pressing the gas pedal? I know a lot of people that complain about poor gas mileage on their trucks, but don't really notice they're stomping on the pedal...


At 10 miles per gallon, real light.


Lol, I thought as much, but had to throw it out there...

Did you go see what your RPMs were at 60MPH, like swart suggested?
What's your tire size? We'll get to the bottom of this, lol.



And if those fuel savers really worked, they'd be a cheap knock-off for an expensive dealership option...

_____________________________


(in reply to swartlkk)
Post #: 20
Login OR Register now to post a reply to this forum topic.
Page:   [1] 2   next >   >>

 
Blazer Forums >> Mechanical & Maintenance >> General Tech Help >> 2nd Gen (1995-2005) Tech
Jump to:



Featured Sponsors
Advertising Info

Top 10 Posters
swartlkk14473
drperry3901
hanr33481
chevy lover3411
m00nwater3269
eurogoldls3121
paddle_grl2944
hillbillyino2884
wolfpack2834
xblazer012659

New Vendors
AMSOIL - Performance Oil Technology

Add Blazer Forum to your favorites Contact Us | Advertising | Partners | About Us | Archive | Links | Link To Us | Legal | Privacy Policy | © Blazer Forum

Blazer Forum .com is not affiliated with or endorsed by Chevrolet Motors Division or General Motors.