Goldpanda94

Hi all,

Normally when I take off from a light, the car would rev up to 2300 RPM then just stay there or drop to 2200 RPM but continue accelerating nicely. This is with me depressing the gas slightly and holding it at a spot.

I've noticed recently that sometimes when I take off from a light (not like flooring it but slowly with the previously described holding the gas pedal at a certain point), the car will start moving, get up to 2300 RPM and 20 mph then it'll drop to around 1700 and just stay there. Even when I depress the gas pedal more up to like 1/2 an inch, the car will keep accelerating slowly (kinda feels like its sluggish and not accelerating at all) but it won't rev up until after that 1/2 inch. At which point, it'll rev up to 3000 RPM and start feeling like it's really accelerating again. It only seems to happen once in a while and seemingly when its above or around 110 degrees F. But that temp could just be a coincidence with the behavior? Not sure.

Any thoughts on what could be causing such behavior or what mechanically may be going wrong? The car just passed 40k miles and has been in Arizona it's entire life. Haven't done a CVT flush yet but I get the oil changed every 5k.

NisCal17

It’s temperature related issue. Mine felt the same way when in traffic. Because when you’re in traffic the car get much much hotter air from all other cars around you. It’s way more than 110F. Hot air gets less dense than cold meaning less oxygen.

Goldpanda94

Hmmm good to know and a bit of a relief that it's just a natural effect of the engine and the environment. Thanks!

Turbobink

iTrader: (2)

I’m not going to get into a diagnosis of this symptom, but this statement is just wrong.

Air, regardless of its temperature or it’s density, maintains the same concentration of O2.

NisCal17

I also not sure about what I have said but hot air less dense by volume than cold air.

lionel2013

You two are both correct, but you missed the point here. Although the concentration of O2 is the same, its amount in the cylinders is less because at constant volume but lower density the mass of the component is less. That is what our fellow board member is saying.

MadMax07SL

Couple things, #1, you are using premium 91 or 93? Could be a dirty intake, air filter full of dirt and debris, buildup on the throttle body...check filter, clean throttle body, run some fuel treatment are a few things to start with...

Goldpanda94

- Using mostly Costco Premium I think its 91?
- I actually just cleaned out the air filter after reading your comment, and the car does feel a lot better, though it was only 89 degrees this morning, Hopefully when its over 110 later today it continues feeling the same!
- I'll look into the other stuff you mentioned too but thanks for the help so far, hope it was just the dirty air filter haha

MadMax07SL

You'll want to get a new filter, just knocking out the dust will help a little, but if that filter has 40k miles on it, it's well past due for replacement. You should check the filter a few times, every 10-20k, and replace any time it seems restrictively full. I'm not sure what the actual interval is, but max these things can get is 30,000 in normal non dusty driving. interval varies. I personally went with K&N years ago and clean and re-oil about once ever 10-12k miles, or if it looks too dirty when I check it. I get more clean flowing air intake that way, instead of trying to make a cotton one last a little longer, and reusable is way cheaper once you get past the 3rd or 4th cleaning as opposed to replacing it outright every 15-20k

Goldpanda94

Nah it was on 2 OEM filters before I switched to K&N at 22k miles. Though admittedly I totally forgot about looking at the filer again since then. I'll probably spray it out, but do you need to reoil it? Can I just wash it out and replace without oiling it?

Richard66

Sure you can, then you can watch all the dust particles with their smiley faces on as they proceed straight through to the cylinders.

Goldpanda94

lol got it, I thought you could just rinse it but I guess it makes sense to have to reoil it since there was oil there to begin with

MadMax07SL

Re-oiling is both required an art, don't mess that up. 9 outa 10 car mechanics recommend not going with the KnN filter for the simple reason is most people totally mess up the re-oiling process. And trust me, you want to use the provided cleaner. I rinsed mine out just this weekend, for fun I rinsed it without using the soap, just hot water, not much came out. Hit it with the cleaner, let it sit 10 minutes, all sorts of black stuff came out. Then you gotta dry it completely, then oil it. the art is getting full coverage without drenching it. Once you are done' wipe off ALL excess from the rim and blot the filter itself, also just inspect it good for excess. I usually let it sit out in the sun for a bit too. With all that, I still normally won't drive the car for several hours afterwards. I love tinkering on cars, since mine has a warranty still, I can't do much on it myself, so for me the time spent is just leisure. I also clean out the throttle body every time I do the filter.

In all honesty, if you don't want to deal with the hassle of re-oiling, there are plenty of high flow filters out there that are replaceable.

BlakMaxiJoey

this mini-thread brought my tiny brain back to school.... i wonder how i passed thermodynamics. lol

BlakMaxiJoey

maybe my obd reader, coupled with an app that reads sensors instantaneously-ish, is sub-par, but at 70F and sitting in traffic, the MAF sensor reads almost 110F.

please, correct me if i am wrong on this...

RickSmith

https://maxima.org/forums/8th-genera...-sluggish.html