Very bad gas mIleage

Bought a 2002 Envoy slt about a week and a half ago and since then filled up twice. Seems i am getting 13.2 mpg says the truck. I calculated with getting 205 miles on a 15.8 to very close to 13. Either way this is very low. I am bringing the truck into chevy next week with a long list of items to fixwhich i just typed up and am having them sign it. But as far as gas mileage goes , this is bad isnt it? Not sure if fuel filter was changed or not. P.S. Here is the list i typed up in case anyone else has these problems. But for the most part the truck runs mint. Also want to ask if and make sure that the rear windshield washer gets its fluid from the same container as the front windshield wipers and front headlight washers?

Here is the list..

2002 GMC ENVOY Repairs Needed

1) Bad Gas Mileage 13 mpg with a combination driving of city and highway 50/50
Is fuel filter original?
2) Rear windshield wiper spray not working
3) Clicking when drivers door is open and shut
4) Both Side view mirrors not calibrated. Rear view mode does not return to original settings when taken out of drive. Mirrors do not return to driver 1 and 2 settings correctly. Mostly occurs with passenger than driver side mirror.
5) Passenger rear door weather stripping shot
6) Slight, but very noticeable, vibration over 60mph
7) Kickback felt when coming to complete stop, feels like something is moving around in front end.
8) Drivers windows buttons…Top 3 do not light up (Window lock, front driver and passenger window control button)
9) Rear windshield wiper hard return down onto trunk when shut off.


Please respond thanks

I have the same problem with my side mirrors with both of them but like yourself mostly with the passenger one. I have to reset the passenger one everytime I get in the car. To be honest I have not taken it in to the shop for this problem because I have had to take it in for other things and it gets so frustating having to take it in every other week. I'm wondering if other people are also having the same problem. Mines is a 2003

I have a 2003 SLT with 17,000 miles and is almost 2 years old.

1. Gas mileage at 50/50 highway/city is between 18.0 and 18.5. I keep extensive records and the low tank was 17.3 and the high tank was 22.0.

2. Rear washer is fed by same tank as front. However, it uses a different pump so your rear pump is probably bad.

3. No comment.

4. Memory mirrow return problems are common on this vehicle. I had problem early on with both mirrows. They were reprogrammed and still don't work precisely as they should.

5.There is a point where the inside weatherstripping has a joint and both of mine don't meet exactly proper either.

6. No problem with mine. Vehicle is VERY smooth at all speeds.

7. No comment.

8. ALL buttons and switches light up.

9. There is a noticeable thump when rear blade parks but at least on mine, I consider it normal.

I hope you enjoy your vehicle as much as we are enjoying ours.

C.B.

Thanks for the reply. I took my truck in today and had the list ready for them. they fixed everything but the gas mileage they said there is nothing they could do about it, it is what it is, and it is a truck!!! But i think averaging 13.2 is not right . As far as the vibration it was rotation and balancing of tires. All work was stupid SH**. the rear window washer was not the motor but a little plastic piece. The lighting of switches was that they werent plugged in all the way. I dont know what to do about the gas mileage. Please someone help.!!! Thanks I would be happy getting 50/50 17mph that is what i thought it would be at!

I don't care what they say, 13.2 mpg under almost any circumstances is woefully low and I would be complaining also. You might want to bump your complaint on up the line with the next stop being the Service Manager.

Good Luck, C.B.

I just called another chevy dealer and a gmc dealer and they said that is about right on what i should be getting gas mileage wize. What can be done then if everyone says i am wrong please help!!

Also am i putting the wrong gas in i assumed it would be 87 since i did not get an owners manual is that what everyone else uses?

I would ask that dealer to please explain why he sells vehicles that are rated at 16 city, 22 highway (Envoy L6) but says 13.2 is about right after you buy it!!!.

87 Octane is the proper fuel. Using a higher octane will not change fuel mileage.

C.B.

As for gas mileage, check the production codes in the glove box. If you see GT5, GT4, or G80, that will explain why you are getting worse mileage.

I just bought a 2002 Envoy and am getting not even that good of gas mileage. But it has a GT4 and G80 rear (4.10 gears, positraction) which are way too tall for most cruising -- they're designed to be great for towing.

If you have a GT5, you've got 3.73 gears; bad, but not AS bad as the 4.10's. MOST of these trucks come with 3.42 non-posi. rear ends in them, those are the ones that get the 16+ MPG.

87 Octane is the proper fuel. Using a higher octane will not change fuel mileage.

C.B.

actually 89/93+ can lower gas mileage because the engine isn't at a high enough compression ratio to burn it completely; this means you'll have to suck more gas to keep a proper A/F ratio and have more work to be done at tune-up time because there will be more numerous carbon deposits on the heads, plugs, and valves.

None of the codes that u mentioned are in the glove compartment codes
What else should i check for? And why would there be different rears. I do have the tow package on the slt? Duh so maybe they have the more powerful rear for the more powerful tow but how do i know what my rear is, did not see any of those codes on the glove sticker

None of the codes that u mentioned are in the glove compartment codes
What else should i check for? And why would there be different rears. I do have the tow package on the slt? Duh so maybe they have the more powerful rear for the more powerful tow but how do i know what my rear is, did not see any of those codes on the glove sticker

If those three codes are not on the sticker, you've probably got an open-rear with 3.42 gears (the default that most are ordered with) -- you CAN have a tow package and not the different gears; most of the ones with it were customer special orders, not dealer-stock orders.

I forgot to mention it before but the code for the normal rear is GU6.

Aside from that, I guess I would take your truck to a non-GM shop with ASE certified techs... Midas, Tuffy, any of these will do. Have them check everything that would be swapped out in a tune-up (plugs, wires, PCV valve, air filter, etc.) and have them check the differentials and transfer case for unusual amounts of deposits in the fluid. Past that, I'd run some injector cleaner through it to see if maybe you just have carbon buildup on the injectors, valves, or plugs.

Good luck! For right THIS minute, my Envoy is running properly. We'll see how long that lasts :screwy:

I have an 2002 Envoy with the 4.10 & G80 axle. I get about 14.5 in the city (I use Mobil 1 5w-30 synthetic in my engine and just changed my trans fluid and axle fluids ) I dont know if that has anything to do with it, but before I changed my trans filter/fluid and axle fluids I was getting about 13.5. I also keep my tires filled to the posted max on the door sticker. Your gas milage really doesnt sound all that bad, really. My Envoy has a lot of equipment that makes it heavier- autoride, leather, cargo organizer, etc. etc. but I still get 14.5, at least thats what my Info center tells me.
Check your air filter. I replaced mine too, forgot to mention that. The air filter will make a BIG difference in gas milage, if its dirty. Change your oil. Go for a semi-synthetic or full synthetic. Do NOT use GM's OLM for your oil changes, if you arent using synthetic oil. Check your tire pressure and adjust if necessary. Just my $.02

Ps. My 2000 Jimmy SLT that I traded in for my 2002 Envoy SLT got WORSE gas milage than the Envoy and had less horsepower/torque and was smaller.

I also have a 02 Envoy and asked the dealer about the mileage. The dealer said new, right off the lot you may only get 14-15 mpg - I get arount 18 city - 23 highway. It was worse orginally and I made them change the fuel filter - 3/4 hour job

ha... well I just discovered why my truck is getting "break in" mileage... My '02 has a replaced motor in it -- build date on the chassis was 6/01 and the engine block is stamped 1/25/03....

what I don't know for certain is how many miles are on the new motor; nothing was ever said or revealed to me when I bought it, nor did it show on carfax.

thats nice to find out!! WOW!!!

In reguards to the gas mileage i am gonna be changing the fuel filter and changing to synthetic within the month so we shall see how it goes and i am also gonna call gm and tell them what a wonderful service department perfromance chevrolet has in east meadow long island... Not!

NOT!!

Hey, thats actually some good news for your problem. I am actually forseeing replacing my 4.2l DOHC in the next 25-30k miles because of all the noise it makes. In the morning my Envoy is very noisy for the first 5-10 miles. Just a lot of valve train noise, maybe some piston slap going on in there. I was hoping my 02 Envoy is covered by the extended warranty GM put out on some 02 4.2l engines because they were having problems with the piston sleeves/pistons. Crossing my fingers ;)

Glad you found an answer to your question. However, dont expect your gas mileage to get "that much" better than what it is now. Expect 15 city/ 20 highway and thats probably only in the summer obeying the 65mph speed limit. Still consider switching to a synthetic or semi synthetic, it never hurts

Hey, thats actually some good news for your problem. I am actually forseeing replacing my 4.2l DOHC in the next 25-30k miles because of all the noise it makes. In the morning my Envoy is very noisy for the first 5-10 miles. Just a lot of valve train noise, maybe some piston slap going on in there. I was hoping my 02 Envoy is covered by the extended warranty GM put out on some 02 4.2l engines because they were having problems with the piston sleeves/pistons. Crossing my fingers ;)

Glad you found an answer to your question. However, dont expect your gas mileage to get "that much" better than what it is now. Expect 15 city/ 20 highway and thats probably only in the summer obeying the 65mph speed limit. Still consider switching to a synthetic or semi synthetic, it never hurts

for my truck, I only run Mobil 1 5W-30 and a K&N Air Filter. Both are already on the truck. :grinyes:

I have an 02 SLT also and it has 26225 miles on it. I have only had it for a month, when I had several problems with it. First I had a tapping noise in the motor. I took it back to the dealer, and yes I do have the extended warranty. I was told that I had to get my whole top end of the motor replaced. Luckily it was covered by the waaranty. For as the gas mileage issue I burn 91 octane and I get excellent gas mileage. But I am going to cantact the dealer do to what was said about burning higher octane gas.Hey, thats actually some good news for your problem. I am actually forseeing replacing my 4.2l DOHC in the next 25-30k miles because of all the noise it makes. In the morning my Envoy is very noisy for the first 5-10 miles. Just a lot of valve train noise, maybe some piston slap going on in there. I was hoping my 02 Envoy is covered by the extended warranty GM put out on some 02 4.2l engines because they were having problems with the piston sleeves/pistons. Crossing my fingers ;)

Glad you found an answer to your question. However, dont expect your gas mileage to get "that much" better than what it is now. Expect 15 city/ 20 highway and thats probably only in the summer obeying the 65mph speed limit. Still consider switching to a synthetic or semi synthetic, it never hurts

Bought a 2002 Envoy slt about a week and a half ago and since then filled up twice. Seems i am getting 13.2 mpg says the truck. I calculated with getting 205 miles on a 15.8 to very close to 13. Either way this is very low. I am bringing the truck into chevy next week with a long list of items to fixwhich i just typed up and am having them sign it. But as far as gas mileage goes , this is bad isnt it? Not sure if <a href="fuel%20filter" onmouseover="window.status='fuel filter'; return true;" onmouseout="window.status=''; return true;">fuel filter</a> was changed or not. P.S. Here is the list i typed up in case anyone else has these problems. But for the most part the truck runs mint. Also want to ask if and make sure that the rear windshield washer gets its fluid from the same container as the front windshield wipers and front headlight washers?

Here is the list..

2002 GMC ENVOY Repairs Needed

1) Bad Gas Mileage 13 mpg with a combination driving of city and highway 50/50
Is fuel filter original?
2) Rear windshield wiper spray not working
3) Clicking when drivers door is open and shut
4) Both Side view mirrors not calibrated. Rear view mode does not return to original settings when taken out of drive. Mirrors do not return to driver 1 and 2 settings correctly. Mostly occurs with passenger than driver side mirror.
5) Passenger rear door weather stripping shot
6) Slight, but very noticeable, vibration over 60mph
7) Kickback felt when coming to complete stop, feels like something is moving around in front end.
8) Drivers windows buttons…Top 3 do not light up (<a href="window%20lock" onmouseover="window.status='Window lock'; return true;" onmouseout="window.status=''; return true;">Window lock</a>, front driver and passenger window control button)
9) Rear windshield wiper hard return down onto trunk when shut off.


Please respond thanks


I purchased a 2003 envoy last year and have had numerous problems with mine. I also have had to get the rear wiper sprayer replaced as you have, along with back up lights malfunctioning, front wiper motor looked at for warranty purposes, my power steering went, gas sensor for emissions was faulty and fixed, and now having problems with my liftgate not opening and or fuctioning properly due to liftgate protector. Hope you get some enjoyment out of your envoy.

Ok so is there anyone out there that is actually happy with their envoy? LOL All i keep hearing is horror stories and yet the truck has a great write up! I guess there are horror stories for every make and model of every vehicle!!

Ok so is there anyone out there that is actually happy with their envoy? LOL All i keep hearing is horror stories and yet the truck has a great write up! I guess there are horror stories for every make and model of every vehicle!!

I love mine.... when it works LOL. :icon16:

No seriously, I don't think they have THAT bad of problems for the most part; its just that the ones you find on forums like this are here because our trucks have issues more than most :newburn:

Ok so is there anyone out there that is actually happy with their envoy? LOL All i keep hearing is horror stories and yet the truck has a great write up! I guess there are horror stories for every make and model of every vehicle!!


I LOVE LOVE LOVE LOVE my Envoy. If it were ever to be taken from me, they would have to pry the truck from my lifeless, pale, dead rigor mortis fingers.

Ok, ok so thats a little extreme. Serious, after searching for the "right" vehicle for years now I have found the one. The Envoy is here to stay.

Hey guys here is something I think everyone will appreciate, I had the same problem with the mirrors going out of sync, I took it back to the dealer and they fixed it by upgrading the software. I realized by dealing with computers if you do not have the latest software you will always run into problems. P.S. Inspite of all you may have heard from me, I would not trade this truck at all. I LOVE MINE SLT ENVOY :).I LOVE LOVE LOVE LOVE my Envoy. If it were ever to be taken from me, they would have to pry the truck from my lifeless, pale, dead rigor mortis fingers.

Ok, ok so thats a little extreme. Serious, after searching for the "right" vehicle for years now I have found the one. The Envoy is here to stay.

OK well everything is fixed they updated the software today on the truck mirrors and they work perfectly. I also added some fuel injector cleaner and i am not crabby about the gas mileage anymore i will update this week gas mileage next week thanks for the heads up everyone. I love the truck all in all and in 5 years its all mine. LMFAO

Just a comment:
I returned from a trip to southern Utah from northern Utah today and my average miles per gal was (by on board computer) 20.2. Around town it has been 17.6. The rear gear is a 4.11 G80. I feel that this is real good from reading the previous posts. My highway speed was 70 going down and 75 returning. Milelage was the same both ways.
Denny

I live in Michigan and my gas millage has been 17 to 17.5 in the winter and 20 to 21 in the summer. I have a 4.11 rear end with positraction. I use Mobil midgrade gas (it will keep your injectors cleaner) and I use Mobil 1 as my oil. I have no complaints on gas millage, but I have had my share of other problems.

Nreeves:
I to have a few other problems. We have had trouble with the mirrors not returning to the program presets. I think finally they have solved the problem. Last week the door modules were reprogramed and that lasted until we got out of the dealership. This week they replaced the mirror drive motors and that I believe has the fix at least they were still working last night. One other problem that hasn't been taken care of yet is that the engine has a cold knock when started. As it warms the knock will diminish but is much lighter. I have the extended warrenty and they are working out the details as to when it can be fixed. Don't know just what to think of that one. Sounds like a light rod knock if there is such a thing. The engine is a 4.2 inline six.
How about the problems you are having?
There sure isn't much activity on this forum is there?
:rolleyes:
Denny

I now have 75k miles on the Envoy and we had our share of problems. I think we have most of the problems solved. I shouldn't say that..... When the car was quite new we had it that it wouldn't start, after 3 times the dealership installed a new starter. We had mirror problems like others have complained about 4 times, we had the speedometer go to 120 mph and I was going 60 mph with traffic 2 times, after stoping and shuting the car off it was normal. We also had some recalls and our latest problem was the oil pressure went to 0 and the car stopped. Found no problem and when it was at the dealer the service 4x4 light also came on. The dealership replaced the transfer case control module. I also had to replace the battery because it failed a load test. Could have been the problem for some of the problems we were having with the oil pressure. It read 9.6 volts and it had to read 12.6

Few tips on gas mileage savings here http://www.envoyforums.com/showthread.php?t=56