I posted previously that my '06 G35 sedan is running fluttery and a tad loud during idling like at a red light. I can feel my seat vibrating and the car just feels "fluttery". Maybe I'm not too bright but since I bought the car used last year, I've been putting 87 octane gas in my car. Do you think this could have caused an issue with the way my car is running? Could I have caused some type of build-up? If so what would be the treatment? Someone mentioned throttle body cleaning but I'm not THAT handy. I replaced the air filter, didn't help. I also used a treatment of Lucas fuel additive and that didn't help.

This is what the manual says so I've been using 87:

FUEL RECOMMENDATION
Sedan Automatic transmission
models: Use unleaded regular gasoline with an octane
rating of at least 87 AKI.
For improved vehicle performance,
INFINITI recommends the use of unleaded
premium gasoline with an octane rating of
at least 91 AKI number.

 

You can try some Redline Complete Fuel System Cleaner, but you may need to have the fuel injectors flushed out/serviced by a mechanic. As for cleaning the throttle body, it isn't that hard - you just need to remove the intake tube (a screwdriver is all you'll need) and take some throttle body cleaner (you can get it at any auto parts store) and a toothbrush and clean it out.

 

G35fromPA:
Thanks for the reply. So are you saying it's possible that by using 87 octane I may have buildup? So it's POSSIBLE that 87 does clog things up? I saw a video on youtube with someone taking the throttle body out on a G35 and it was a TON of screws and was buried. Maybe that was an older G35, not sure. It sure looked complicated. I'm willing to clean the throttle body myself if it's a simple one two thing. The guy at the auto part store said cleaning the throttle body is fragile because if you get one piece of dust in there you have BIG issues. Not sure if this is true.

 

Hate to do this to you, but why buy the car and then put 87 in it? If you wanted to run 87 octane gas, buy a Civic. The G holds about 20 gallons of gas, 20 gallons * .20 cents per gallon = $4.00 per fill up. Use premium, please. Will it do anything? Yes. You'll get more performance from the car because it won't knock like it might on 87 octane. You'll also get less carbon deposits and a cleaner-running engine.

With that said, most likely residue/carbon deposits left in the fuel system from lower octane fuel. You can run fuel injector cleaner, for some reason Infiniti is against it. I would first clean your throttle body. If you have any aftermarket filters, you may also want to (carefully) clean your mass air flow sensor in your intake tube.

You may have a bad tank of gas too. There is a DIY here for throttle body cleaning and it's not too bad. Try that + fill up with some premium gas and see if it solves your problem.

Again, hate to beat on you but running 91 octane is worth it. Keep us updated.

 

Bauer,
I know Bauer, like I posted in my original comment, the manual says minimum 87 so stupid me I assumed 87 would be ok. DUMB *** I am. I hope it's not something permanent that I caused. OK, well thanks for the lashing, I deserve it.

 

Nah, nothing permanent. Just start using 91 and clean out the throttle body and fuel system. Worse case, take it to a mechanic and they can actually flush it for you. You'll be fine. Watch the double-posting before you get flamed.

 

My local mechanic (tire chain store) said they have a treatment that treats the whole fuel system and throttle body including MAF that costs like $120. He said it's like an additive that goes into the gas tank and it sends this big black cloud of smoke out of the exhaust which is all the dirt coming out. Does this sound like an adviseable thing to try?

 

I am not finding the DIY for throttle body. I'm searching everywhere. :-(

 

Hmm, I can't find where the original post is either now that you mention it. In any case, here's the direct link to the YouTube video.


You can get the additive yourself from an automotive store like Kragen, but if you're not comfortable dumping fluids in your gas tank you can bring it to the shop and have them do it. That, on top of cleaning your throttle body should take care of your issues.

As a side note, I'm not sure how in the world their fuel additive cleans the mass air flow sensor...if you have any gas line going to your mass air flow sensor you have HUGE problems, haha. Either way, mass air flow sensor cleaner can be had for a few bucks. If you're going to do it manually, be careful. With both the throttle body and the mass air flow. You don't need to freak out because you think you'll break it, just don't exert a lot of force. Treat it like you have to pay for it if you break it. It's that simple. Not a hard task though.

 

Yes, this is the video I watched yesterday. Sorry to sound like a wuss but this is way too involved for a Boston city girl like me. I'm just not THIS handy. I added Lucas fuel additive to a full tank, it didn't help. Is that along the lines of what you mean by using an additive or should I try a different type? Maybe the MAF sensor wasn't part of the cleaning out they said they could do but definitely the throttle body.

 

Yea, that was the kind of additive I was referring to. If it didn't help, your problem is most likely the mass air flow or throttle body. You can get a can of mass air flow sensor cleaner and clean it (this isn't too hard to do, just find the harness that plugs into the intake pipe, look at the screws on either side of it, unscrew them and pull out the sensor). Again, be careful with the mass air flow.

I wouldn't trust an additive to clean the throttle body. Have it hand cleaned by your local mechanic (not tire shop) or take it back to the dealer. They do a full fuel cleaning and manual throttle body cleaning for $280 (not cheap, but supposedly helps). That'll be the first thing they tell you to do too, if you bring it to them and they can recreate the problem.

 

Actually Bauer, the dealer couldn't recreate the problem. I took it to them. I got the same answer I always do "we don't notice what you're talking about and everything looks fine."

 

You can just specifically request the fuel injection and throttle body cleaning service. I can't guarantee success but if nothing else has changed that is most likely.

 

i have a weird vibration/flutter when my car is in neutral and idle.im not sure if it is the same problem ur having my rpms get really low and it feels like my car is about to stall..infiniti told me its cuz i have a cold air intake..wouldn't that help the car breath??idk

 

Yes, basicly when idling or in park, not when driving along. However mine doesn't seem like it's going to stall, it is running strong and steady. It's just vibrating. I can feel my seat vibrating and there's an annoying fluttering from the vibration. What is cold air intake?