Question about 1999 Chevrolet Silverado 1500

2 Answers

Very Poor Gas Mileage on 1997 Chevy Silverado

I tow a 6000 camper trailer, and for my first outing this season on flat ground was getting about 5 mpg. Over past years, in the mountains I typically get 8-12 when towing, so I was very surprised how low this was. I am thinking of changing the O2 sensors to try that first. Any advice on what I could try, or how to try to diagnose this?

It is a K1500 5.7L with about 80,000 miles

Thanks,
Kevin

Posted by on

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 589 Answers

I would do the usual tune-up stuff first.. plugs, wires, cap, rotor, filters, PCV valve, etc. Try to avoid aftermarket parts if possible. You may pay a little more for OEM GM / ACDELCO parts, but my past experience showed me it's not worth the aggravation.

I'm guessing this is a TBI. The throttle body may be getting gummed up. This is a pretty common issue with the 4.3 & 5.0 / 5.7's. Even the thirsty big blocks were prone to this. Pick yourself up a base gasket while you're at it, and a can of "Berkible 2+2 gum cutter". Wear rubber gloves when using this stuff (don't worry, it's "sensor safe"). Remove the throttle body and when you turn it over, you'll be surprised at the carbon build-up in all of the passages, etc, and how much better it will run afterwards.

Check for cracked / dry rotted vacuum lines too while you have it all apart.

I'm actually surprised you were getting the mileage you were (8-12), considering it's a 350, and the weight of the camper.


Posted on Jul 22, 2008

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I have very poor gas gas mileage in my 1997 s10 truck .but the truck runs good, but it only get about 10 miles per gallon.

Posted on Apr 08, 2013

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Low gas mileage city and hiway @ 4-5 MPG below MSRP sticker data of 15 and 21MPG on a NEW 2013 Silverado. 2000 miles on odometer and mileage not improving.


is this calculated mileage or what the estimated mileage is showing on the dash. Have you checked to see what you get on just the freeway?

What are your driving habits like?

How is your tire pressure?

Do you make a lot of short trips?

Apr 11, 2013 | Cars & Trucks

1 Answer

Poor fuel economy


If there is a vac leak or a split in the hose between the intake and the MAF you can get a code for the sensor. The code is saying the data from the sensor is not what it should be, not necessarily that the sensor has failed.
Clogged air filter or box could cause a problem too.

Jul 05, 2012 | 2005 Chevrolet Silverado

1 Answer

Poor gas mileage from my 1999 silverado 2500 tih a vortex 6


How bad .. thats a heavy truck..12..14 mpg.. is the norm I believe....

Mar 02, 2011 | 1999 Chevrolet Silverado 2500

1 Answer

Instructions for wiring a moving trailer connector


accessconnect_logo.jpg


Trailer Wiring Diagrams 4 Way Systems

4 way flat molded connectors allow basic hookup for three lighting functions; right turn signal / stop light (green), left turn signal / stop light (yellow), taillight / license / side marker (brown) and a ground (white).

4%20way%20wiring.jpg 4way_vehicle.jpg 4 way tow vehicle side.
4way_trailer.jpg 4 way trailer side.
5 Way Systems

Same as 4 way system listed above but adds a extra blue wire for brake signal or auxiliary power. Used on pop up camper trailers or utility / boat trailers.
5way_vehicle.jpg 5 way tow vehicle side.
5way_trailer.jpg 5 way trailer side.
6 Way System, Rectangle Plug 3/4 inch by 1 inch 6 way rectangle connectors right turn signal (green), left turn signal (yellow), taillight (brown), ground (white). The red and blue wire can be used for brake control or auxiliary. Use on a small motorcycle trailer, snowmobile trailer or utility trailer. Can also be used as custom wiring on trailers with 3 light/wire systems. See "Tow Vehicle Taillight Wiring" below.
6way_rectangle_1.jpg 6 way tow vehicle side.
6way_rectangle_2.jpg 6 way trailer side.
6 Way Systems, Round Plug

Round 1 1/4" diameter metal connector allows 1 or 2 additional wiring and lighting functions such as back up lights, auxiliary 12v power or electric brakes. Note: The black (sometimes red) 12v and blue electric brakes wire may need to be reversed to suit the trailer. Check with a test light or VOM. Uses: horse trailer, travel trailers, landscaping trailer, car trailer, etc.


6way_vehicle.jpg 6 way tow vehicle side.
6way_trailer.jpg 6 way trailer side.
7 Way Systems

Round 2" diameter connector allows additional pin for auxiliary 12 volt power or backup lights. Uses: heavy duty landscaping trailer, car trailer, boat trailers, horse trailer, travel trailer, construction trailer, etc. Check with a test light or VOM.


7way_vehicle.jpg 7 way RV flat blade tow vehicle side.
7way_trailer.jpg 7 way RV flat blade trailer side.

Jan 01, 2011 | 2001 Pontiac Montana

1 Answer

F-350 Supeer Cab, long-bed, dually, with towing


I don't know how much better gas mileage you will get with a gear change. I don't think it will be worth the cost verses saving a couple mpg. The 5.4L engine is kinda small for this size truck. The better way to go would be a cold air intake and an aftermarket exhaust this will easily give 5-10 mpg increase over stock and won't sacrafice any power when towing

Jun 23, 2009 | 2000 Ford F350 Super Duty Super Cab

2 Answers

I only have taillights coming out of the trailer plug


so, the trailer has no brake lights, or turn signals, just tail lights? Everything (all lights) on truck work ok? What do you have for trailer wiring hook up 4, 5, 6, or 7 way? There is no fuse, the lights all work off the tow vehicle lights, so if the tow vehicle lights all work properly, it's probably a wiring problem, such as bad grounds, loose connections, etc. Get a volt meter and check voltage at truck plug to see if power is getting that far. If truck plug in is ok, wiring problem is the trailer. Make sure all grounds are tight and rust free, that's a common problem.

May 20, 2009 | 2004 Chevrolet Silverado

1 Answer

Brake controller not communicating w/ 7 pin connector


what type controller did you install? Is this a camper or trailer? Is the controller hydraulic plumbed into master cylyder? Important to know how to adjust rheostat for sensitivity. If set at minimum the system is basically on the edge of not sending any signal to towed unit. The intructions should explain how to make this adjustment. If set too sensitive trailer brakes will lock up before the tow vehcle starts to brake. Controller should be set so trailer starts braking just befor the tow vehcle. If not the trailer will tax the tow vehicle brakes by pushing. Its set right when you feel the combination stretching out. trailer first then tow vehcle. Good luck and remember, if truck brakes first and too hard you risk a jacknife. All light voltages should be system voltage. Brake voltage is variable depending on setting on controller. Understand your breakaway brakes and how they work. breakaway breaks require an auxillary battery. Again, good luck and you know where to find me if I can be of anymore help.

Apr 13, 2009 | 2003 Chevrolet Silverado 2500HD

1 Answer

1991 CHEVROLET SILVERADO 2500HD 7.4 Litre 4x4 tow capacity


you can pull the boat no problem. as putting in a 6.2 for the 454 you will need to change wire harness inside and out..im the brake booster...... the gear ratio in the rear ends ..fuel pump ..im guessing you have a truck you will be using for parts.. if you are doing for fuel mileage you will be disappointed you will only gain a couple of mpg .. hopes this helps

Dec 08, 2008 | 1991 Chevrolet Silverado 2500

2 Answers

Poor fuel milage on 2002 tundra. sr5 ext cab 4x4, 4.7l


when you tow your milage is going to go way down. If this is something you do a lot Then you need to invest in a on the fly ajustable computer and it will change your computer settings for the job you are doing on the fly. It will give you better performance for towing when you want to tow. better milage for driving when you want to drive. You can also use it if you want to change the tire size, it will allow you to change the tire size without loosing your speedomiter settings.

Sep 05, 2008 | 2002 Toyota Tundra

Not finding what you are looking for?
1999 Chevrolet Silverado 1500 Logo

2,610 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

60541 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21927 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6811 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...