# bad mileage?



## irollforever (Jan 20, 2009)

I bought a used '96 sentra GLE a couple months ago in august of '08. it was garage kept, only had 31,000 miles and was in good shape. has been running fine since.
I decided to calculate my mileage recently and I got only bout 17.5 mpg. This doesnt sound a lot to me, but this is only my first car and I dont know a lot about cars, or this car even so I may be wrong.
I dont know what the previous owner had replaced, fixed or anything because she passed away soon after i bought the car and hadnt told me much about it. being that there was very little mileage I figure she didnt drive much or have to replace anything.
So I just wanna know is this a bad number for this car? should i be getting more mileage? If I should be, what should I look to replace or check?


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## sonicgundam (Aug 15, 2007)

have you done anything to the car yet?


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## irollforever (Jan 20, 2009)

nope. the only thing ive really done to the car besides driving it was like adding brake fluid, antifreeze, oil change, that kind of stuff. and some cosmetic stuff like put a spoiler and change headlight bulbs. but that wouldnt matter i dont think.
and also its cold and snowy here in NY. idk if the weather would be a concern.


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## sonicgundam (Aug 15, 2007)

does it happen to have a K&N air filter on it per chance?


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## irollforever (Jan 20, 2009)

ive got no clue. everything on it is all stock im pretty sure.


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## sonicgundam (Aug 15, 2007)

is your idle relatively high at startup? if your engine is having trouble heating up, it will run rich, meaning the car adds more fuel, to help it warm up. if thats the case, it could be as simple as doing a coolant flush. but it also might reveal that you need a new radiator or heater core.


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## irollforever (Jan 20, 2009)

it doesnt seem like its having trouble heating up. it doesnt really take more than 2 minutes unless its like below freezing outside, then it takes up to maybe 5. what would be considered high at startup?
i was planning on doing a coolant flush once it gets warm out actually. but do you think id have to replace the radiator or heater core even though the mileage is so low and all? i dont think the cars been through much before i bought it.


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## jcantol33 (Jan 20, 2009)

thats weird i have a 97 gxe with 35k orig from florida now in mn and i have been having the same problem right around 18-19 mpg on high way i was told to check plugs wires rotor, cap all that random stuff and still have not found the answer is your car dripping and oil cause i blew my front main and noticed a small increase wonder why haha is your car an auto or man.


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## irollforever (Jan 20, 2009)

maybe ill check all that stuff soon. but nope, no dripping anything. its automatic.


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## jcantol33 (Jan 20, 2009)

is it really doggy?? mine was pretty bad and i got a tranny flush could help, i noticed a big diff. when i did it


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## irollforever (Jan 20, 2009)

anybody else have any advice?


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## sentra77 (Aug 3, 2008)

i had the same problem replaced the thermostat and cleaned the heater core because it was blocked and flushed the system and it runs great. i was getting 18-24mpg and now i get 27-32mpg. and i always go WOT in my car


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## irollforever (Jan 20, 2009)

so flushing seems like the best idea. ill try that soon and hopefully ill get more mpg


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## broken_scars (Jan 28, 2009)

*idea*

i have run into a few of these..run an obd2 and see if anything shows up about the idle speed sensor


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## irollforever (Jan 20, 2009)

broken_scars said:


> i have run into a few of these..run an obd2 and see if anything shows up about the idle speed sensor


what is it and how do I do it?


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## broken_scars (Jan 28, 2009)

same thing as the idle air control..its right beside the throttle body...easily screws out and just put a new one in...if you take it to a mechanic he could show you where it is in a matter of seconds and give you a price real fast...


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## irollforever (Jan 20, 2009)

i meant the obd2 haha


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## broken_scars (Jan 28, 2009)

oh ha. it plugs into your vehicle and can read codes to tell you whats wrong with your can. it will be under the panel under your steering colum. you will just feel a plug in down there..takes a couple seconds. if you have a checker or an orileys auto parts where you are they will just let you borrow one and probably do it for you and its free....


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## irollforever (Jan 20, 2009)

hmm dont have any of those around here. but would a regular mechanic have one maybe?


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## broken_scars (Jan 28, 2009)

ya for sure, and most part stores have them


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## irollforever (Jan 20, 2009)

nice. im going to get an oil change in the next week or so. ill ask the guy to run one. or if he knows what the prob is. thanks man


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## maroonsentra (Mar 3, 2007)

irollforever said:


> hmm dont have any of those around here. but would a regular mechanic have one maybe?



Go to autozone or Advance auto and they will do it for free. No codes are going to pull if the check engine light isn't on.


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## irollforever (Jan 20, 2009)

maroonsentra said:


> Go to autozone or Advance auto and they will do it for free. No codes are going to pull if the check engine light isn't on.


well thats not on so forget that idea. 


i figured out im just gunna save up some money and get a nice tune up so i know myself that everythings new and in good shape


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## Recian (Sep 30, 2008)

ok i'll make a good one here. I bought a 95 sentra GXE from the junk yard in may for $750 i knew what i was getting into cuz im a nissan tech i know the general problems on sentras.

it got about 20mpg hwy when i bought it. im like wtf customer sentras are doing like 150miles on 1/4 tank something just isnt right so i began the resto process.

Bosch Fusion 4x plugs, new OEM wires, new OEM cap and button, Air filter, and i added lucas to the gas to clean the injectors(nissan) 

Bang she jumped to 21/22mpg i said ok im getting somewhere

Fuel filter - BIG jump to 23mpg if the car has been sitting it has old gas - bad filter

Tranny drain (mainly cuz the pan was leaking) added 1qt Lucas trans. addative then filled 'er up. gas was about the same but throttle responsiveness went up dramatically.

I said ok 23 isnt half bad but not good enough.

Added Ram air Intake she went to steady 25mpg (no matter how i drove her) Upon doing all this she began to run much better. after the point where u get the ignition and fuel fixed dog the hell out of that car. if it's been sitting (31000 miles) then it's got carbon buildup. change the oil and drive the crap out of it. i didnt do that. i rebuilt the engine my rear main went out along with valve stem seals and a timin chain guide (as per NISSAN recall) so i rebuilt the engine at 202,000, cleaned the pistons, polished the valves and everything. now no matter what i do she wont get less than 25mpg. recently i hooked up the computer.. found a/f alpha at 110% meaning she's running dead rich which is also effecting my performance. I"ve got the timing set to 4-6 BTDC as opposed to 8-10 BTDC stock to compensate for power but i'm thinking i've got a sluggish O2 but i gotta dig deeper. Sorry for the long ranting post but i hope some of my story of my sentra helps


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## irollforever (Jan 20, 2009)

my car was most likely sitting around for a while. the lady i bought it from had some type of disability so im pretty sure it wasnt driven for a whiiiiile before i bought it.

i just got an oil change last week but i just bought stuff for a tune up (spark plugs, wires, air filter, fuel filter, cap, rotor) from courtesy parts a couple minutes ago. i talked to a honda mechanic that i know (he worked for datsun before it was nissan which is pretty cool) and he said tune ups the best bet since i dont know when anything was changed last. i told him the engine was chirping a bit and he checked my belts and told me to order those too if im getting all that. so when i get all that stuff put it in, i think itll run a lot better. hopefully. 
then once it gets a little warmer out here ill probably flush the radiator cause im sure that hasnt been done in a while. the mechanic said that when i do that i should use nissan antifreeze instead of aftermarket kinds cause its better for the car. makes sense to me so ill try it.


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## Recian (Sep 30, 2008)

when you do the belts (it may not be bad) but all nissans are notorious for idler pulleys its like $15-25 from the dealer. may save u some headache if u invest in one because its not if it goes out it's WHEN it goes out and it does it on all nissans. i've seen em seize up and break belts so just a heads up


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## irollforever (Jan 20, 2009)

ill keep a lookout for that. the only belts i got was power steering and alternator.
thanks for the heads up though


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## irollforever (Jan 20, 2009)

so its been a little while and this is what ive done.
-flushed the radiator- did nothing at all.
-tune up including gas filter, air filter, spark plugs, wires, cap & rotor- no difference.

anything else i should check out?


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## IanH (Feb 11, 2003)

From what i have read here the CEL sometimes does not come on right away, it can take time or multiple triggers, and if something is intermittent a code can be stored with no CEL on.
Also if you check your timing check the sticky, make sure the car ECU is in timing mode.
8 deg BTDC is spec, 10 deg BTDC is limit on regular gas. 
15 deg BTDC is MAX recommended stock ECU with premium gas. (presumably not in California with the Premium there. Some Cali residents referred to it here as pump pee !!!) 
Read up on this before you mess with it.


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## IanH (Feb 11, 2003)

Thanks for the idler pulley warning !!!


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## irollforever (Jan 20, 2009)

so i should check for the CEL?


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## IanH (Feb 11, 2003)

Yes I would think you have nothing to lose and information to gain.
Get the ECU read for codes.
If there is nothing stored at least you will know....


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## agoratrader (Apr 7, 2009)

Describe in detail the method you are using to measure your MPG to rule out any user error.


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## irollforever (Jan 20, 2009)

just filling up one day and topping it off. resetting the trip meter to see how many miles i drove. when i get to about a quarter of a tank, i fill up and record the number of gallons put into the car and divide that by the number of miles i drove with that 3/4 of a tank.


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## BasicB14 (Oct 23, 2008)

I have no idea what that could be. I have a 95 1.6 5spd and i get 38mpg on the highway with premium gas. my car has 136,000 on it

and sorry for stealing but is there anything i should be prepared for in terms of service items that are known to go around my mileage?


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## irollforever (Jan 20, 2009)

so its been a while and still no increase. even put a short ram in and no mileage increase, but the car does have a little more pickup than it used to.

i even tried putting onne of those engine cleaners in the gas tank and drove it harder than usual to try and clean out the engine or whatever and it helped for that one time i put it in, but went back down.

is there anything else i should look at, check, or anything. im jealous of everyone else getting so much more mpg than me. and itd save me money too haha


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## IanH (Feb 11, 2003)

Well you could try the O2 sensor.
The first one controls the fuel air ratio for most of the operating range.
I read full throttle hi revs is open loop, so avoid that !!!
i changed mine on a Subaru legacy that i had from new, at about 100K.
I picked up 1 -2 mpg ( it did around 19-20 in town, 28 or so on the highway.)
It had dropped from about 30 - 32 on the highway, 22- 23 in town.
regained about half what it had lost, but of course the speed limits also went up over time.


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## IanH (Feb 11, 2003)

btw my sentra GXE with the 1.6 manual did 35 - 36 highway when new, and by 110K was doing 28 - 30 mpg but at much higher speeds, around 80 mph or so from Dallas to Austin and return, 200 miles each way. and bigger tires.
If i slowed up I would get around 32 mpg at 70 -75mph


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## Ratnose86 (Jun 4, 2009)

How many miles are you getting to a tank?


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## IanH (Feb 11, 2003)

I don't have either of the 1.6's anymore.
I know for a fact there were two fuel tank sizes for the 2001 Sunny I had, so I guess its relevant to ask what model and fuel tank size. This was the same as the 2001 Sentra LHD, but 1.6 L.
But the 200SX SE-R ( 2.0) seems to have a 10.2 or 10.3 gallons when the light comes on to full.
The Sentra with the 1.6 it was closer to 12 gallons from light on to full, typical fill up was 11 gallons. I looked up fuel capacity at 13+ gallons. Actually got over 13 gallons in it one time with the needle below E !!
From Memory the 1.6 GXE did 250-270 around town, on the highway I used to try and fill up in Dallas or Austin, so it was under half full depending how long it was there. But I am sure of the highway fuel mileage, checked it every fill up.
Did that trip off and on for four years, ending about two yrs ago.


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## Ratnose86 (Jun 4, 2009)

Sorry, my question was directed at the OP. With the mpg he is talking about it would be below 250 miles a tank and that doesn't seem possible unless major issues with the computer such as never getting into closed loop operation.


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## IanH (Feb 11, 2003)

Ok.
The worst I ever got with the 1.6 was about 22 mpg in terrible stop and go traffic in Dallas.
And this is with a 5 speed manual.


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## irollforever (Jan 20, 2009)

well i never let the needle go down to e, i usually fill up when it gets to a quarter of a tank or a little lower and usually when i fill up, its like in between 9-11 gallons. but to that 1/4 tank line i usually get in between 200-225 miles.

i was just talking to a friend and he was saying its prob the O2 sensor. he said since it was sitting so long that thats probably the reason. hes going to be installing a new header and exhaust for me so he said i might as well get a new O2 sensor since itll do nothing but help.


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## irollforever (Jan 20, 2009)

does anybody recommend any website or company to get an 02 sensor from? when i check online i see some that run like $130 or so then i see some for like $30.
im not really sure the difference between them or why the price is so diferent


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## Jopet (Aug 10, 2009)

sonicgundam said:


> does it happen to have a K&N air filter on it per chance?


Hi, having a similar problem but not just the MPG but power. I know that the engine is not designed for speed (as Ive been reading in the other topics) but my car is really dragging its butt, even more if I have passengers. Mine has a K&N filter. How does this affect MPG? car description: 1995 sentra GXE, 140k mi, headers, K&N filters, rolling on 16" 205s 50 series, Ever since I got the car: trans fluid changed twice to get it clean as possible last change put in 1 bottle of lucas trans additive. changed EGR valve as the CEL code indicated. used several fill ups - injection cleaning additives both regular and high mileage. repalced fuel filter, spark plugs, wires cap rotor (BTW rotor moves around a bit, a play of I guess a quarter of an inch). right now city its doing 16mi/gal hwy 26/gal at best. when I got it 12mi/gal city, 22mi/gal hwy, and once in a while it goes back to that consumption. he best I had was coming from VA 35mpg/hwy 26/city - I blamed a gas station for this thinking it was the gas that I put in. It does not downshift when I floor the gas pedal. When its running fine, it does downshift and revs really hard. Now it stays in gear I think its 3rd gear from 20mph to 60mph slowly increasing revs. Is there something common to MPG problem with the b14?


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## Jopet (Aug 10, 2009)

I found my car's problem. It was due to my own stupidity. I should have been reading and asking question before changing parts that Im not familiar with. My MAF (K&N) had a thicker rubber body than a thin metal sheet on what was replaced. The sensor holes I drill was not enough and the sensor was barely peeking in the filter. So I guess the ECU could not detect that there is massive air coming in the engine. I trimmed the hole further and carved the holes to get the sensor in that filter. Viola! drove it for about 15 miles and already had about 20 miles before the fix and the needle is still where it was when I had a fill up. I will continue to observe this. Then on to lowering my front end !!!!


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