Acceleration and gas consumption problems.

[skadodie]

hello

i bought my pre-owned 2007 versa s in november of 2008 with only 16,000 miles and no problems; i followed through with regular scheduled servicing and what not.. early last year, i accidentally backed up onto a rock while in reverse, which caused a pipe (i don't remember the name of it) underneath my rear bumper to break, affecting the acceleration and gas mileage of my car. i took it into the dealership and had it fixed; a little less than 2 years and 34,000 additional miles later, i'm having the same problem (only i didn't back up onto a rock this time, or anything else, for that matter..)

my problem for the past 2-3 months has been that i started having trouble accelerating, and the RPMs aren't catching in the right range of MPH (i hope i'm explaining this right..like, the RPMs would struggle reaching between 2-3 while accelerating to 20mph, then again at 35 or 40mph, etc..), and when i would let off the gas, the indicator would rapidly and freely float from 3 RPMs to 1 RPM and then go somewhere in between 3 and 1, and when i would try to accelerate again the indicator would quickly float back to 3 or slightly above. whenever i accelerate after a stop, my car starts to shake a little bit and i can hear a kind of faint whirring AND puttering noise (when i first got the car i never heard that sound and my car would accelerate smoothly..)

as for gas consumption, i usually get 300 miles a tank and now i get about 225 if i'm lucky. i usually have to fill up every 3 days, instead of once a week like i used to..it's getting very expensive to fill up so often, spending $60 a week instead of $30..

the only thing i haven't done for my car (and will still have to wait for another month or so) is to have my transmission flushed..when i hit 30,000 miles they never told me that i needed to have it flushed and at the time i wasn't aware it was supposed to be 30, 60, and 90,000 miles...when i started having problems my car was under 30,000 miles though, so..

i would greatly appreciate anyone's help as soon as possible..thank you!!!

-kasey

[silverarrow27]

It could be a transmission issue, but I would look at your fuel system and air filter maybe. I would start with the how clean the air filter and the air box for starters and then go to the fuel system. Could be that your catalytic converters could be clogged from your exhaust/muffler damage? Good luck with your issue.

[Promise Land]

what did the dealership replace specifically?

[skadodie]

Promise Land, i can't remember for the life of me what the name of the pipe was called...would it help to narrow it down if i told you that it was on the right side, only a few inches away from the muffler?

they also semi-recently replaced uhm..i think they said i had a huge crack in my drive belt? back in march of this year..but that's the most major thing that's been repaired on my car so far..

i went in sometime last week and tried to describe the problem to the service techs, but they said for them to look at it would be $89 PLUS whatever the problem was, and labour..but mentioned that it sounds like it could potentially be covered under my powertrain warranty? but i would have to have my transmission flushed first, otherwise the warranty would be void because it's scheduled maintenance or something? idk..they said for me to fill my gas tank either full to 1/2, or 1/2 to E and write down the number of miles my tachometer reads, and then do it once more and then come back, because until then they couldn't tell me what the problem was..so i finally did that and i got 125 the first time and 100 the second time..

i also noticed that recently while trying to accelerate now when it's going in between 20 - 40 mph the RPM sits at 2 and does move even after i've hit 45mph unless i let off the gas and then try to re-accelerate..not sure if that means anything important or not..

[skadodie]

silverarrow27, the dealership said that my air filter was slightly dirty but that it didn't need to be replaced right away..should i just replace it anyway? is it an easy DIY project? how can i check my fuel system? a friend of mine was telling me the other day that they sell something you pour into your gas tank once it's completely empty and it helps to clean out any gunk that's trapped in it..is that anything along they lines of what you're talking about? or can you tell me how i can check the fuel system? do i need any special tools?

do you think i should mention to the service techs what you think could potentially be wrong with my car? that it could be that my catalytic converters could be clogged from the exhaust/muffler damage?

PS thanks to both of you for trying to help me out!!

[skadodie]

i looked online to check how i can change my air filter, and i found this picture that resembles my current air filter EXACTLY, gross colour and all..should i buy a cheap $20 classic air filter or shell out the extra $20 for the "better" one?

[Promise Land]

would it help to narrow it down if i told you that it was on the right side, only a few inches away from the muffler?

Muffler is on the left side, so not really. If I had to guess you cracked the filler tube that goes into the gas tank. It is metal. There is also the fuel leak canister at the bottom and a crack in it should have turned your service light on the dash on when you backed into something.


they also semi-recently replaced uhm..i think they said i had a huge crack in my drive belt?

A drive belt wouldn't be causing this. That is only to turn your A/C Compressor, Alternator, and other accessories. Have you tried disconnecting the battery and letting it sit for 30 minutes? Stupid suggestion but it should reset the computer to a basic state.

Do you have an auto, CVT, or manual transmission?
You said ~30,000 miles?
What year again?

Where are you in the US?

[skadodie]

WOW, i feel like an idiot when i said that i thought the muffler was on the right side.. my bad i can't remember if my service engine light came on at all after i hit that pipe, but i THINK if i did it came on sporadically..

i actually had to have my battery replaced a couple of months ago, so it was reset back in april.

i have a 2007 with a CVT and just about 50,000 miles on it..my next scheduled service is in a couple hundred miles..and i'm located in southwest florida.. i'm going to check my paper work to see if i can find what it is they replaced and if i come across anything i'll post it here.

[Promise Land]

i have a 2007 with a CVT and just about 50,000 miles on it.

OK, my best guess is that your running into the pipe and damaging the fuel filler tube (my guess) has nothing or little to do with the car not wanting to accelerate.

The auto transmission fluid should be changed at 30,000 miles. The CVT doesn't have a mileage recommendation, but I think the transmission should send a signal to the ECM and turn the service light on when it is time to change the fluid. Next time you get a chance, check what color the fluid is. New it is a cherry pink. When it is close to time for a change, it will be an orange color. If it is a dark orange or worse, please change it ASAP. If the fluid is in need of a change, the transmission may be limiting the power it transfer to the wheels, meaning it would act as you describe. I'm just speculating here, but it's my best guess.

Check the fluid color, and let us know how it looks. we'll keep diagnosing it.

[skadodie]

i actually checked the transmission fluid yesterday, it was orange but it wasn't bright and it wasn't completely dark..the soonest i'd be able to get it checked is around the 5th of november..let's hope my car can make it until then

so the major things i should have done as soon as i can is:
-replace the air filter (i've never replaced it and i'm not sure if it had been replaced before i bought the car..my guess would be no since it was an '07 and i bought it in '08..how long are air filters usually good for?)
and
-get the transmission flushed

am i forgetting anything? or is there any kind of preventative maintenance i can do for my car or anything i should look into getting changed to make my car run more efficiently?

[NODES]

check compression on the cylinders maybe? I have heard a few people require engine replacements.

[skadodie]

i've still got a few days to a week or two to go before i can get my car checked out, but i went through my paper work and back in march of '09 i had to get my exhaust canister and hose replaced, which was causing my gas mileage to suck and my car not being able to accelerate properly..but my check engine light was on when that happened, and it's not on this time.. i'm going to start small and replace the air filter, hopefully that will provide some relief. next will be a transmission flush, then an alignment that they said i needed..

[Eemrek]

check compression on the cylinders maybe? I have heard a few people require engine replacements.

+1

I have an '07 Versa CVT (pre-02/07 manf. date) which started having engine problems at 38K and finally changed the engine at 56K, mostly due to my fault but worth noting only because the MR18 is very sensitive to low-oil conditions.

If the other suggestions that other members here doesn't seem to help, have a mechanic do a compression-check on your engine.

Cheers,
Eemrek