Hi, just had a quick question to try to check with you guys?

So far I've put 25k miles on my Maxima in the year I've had it so I've grown accustomed to how it feels in a bunch of situations. But recently where I live, its been hitting 100 - 120 degrees outside and corresponding with that change, it seems like my cars acceleration behavior has changed a little too.

Previously when I've held the accelerator slightly depressed at a green light, the RPMs would go up to like 2100 or so and stay steady and accelerate smoothly. But recently, while driving the same way and same roads, I've been noticing that the car will go up to 2100 for 2 seconds then will drop to 1700ish RPM and then stay there unless I press harder on the accelerator (there will also be what seems like a dead spot of me pressing the accelerator an inch where nothing happens) until a certain point and then the car will jump up to higher RPM and accelerate faster but then the acceleration doesn't feel as smooth or as quick as it normally behaves. The car kinda feels like its getting held back when this behavior happens. Like I won't feel slightly pushed back into my seat when accelerating like how it used to feel.

This change seemed to correspond with several changes:
-I brought it in for an oil change recently
-Temps started to go over 100 deg (mostly driving during 110 - 120 degree weather)
-I've driven it after washing it a couple times at night when it was 80ish degrees outside and the car felt mostly back to normal
-Did a long stretch, 100 miles or so on the highway in a pack of cars going 100 mph in 110+ degree heat / desert climate (idk how strenuous that could on the car?)

So my question is, does this behavior seem indicative of a mechanical issue (haven't done a CVT fluid flush yet, waiting for 45k miles, I'm at 40k now), or heat sink, or something else? Thoughts before I bring it up at my next oil change?

Thanks!

 

Heat will most definitely drop your horsepower.

 

The density of air at high temperatures is less than at lower or normal temps. Less air (by weight) means less oxygen, means reduced engine performance?

 

Can't help you, but mine seems to have acquired a similar "dead spot" at round 20k (I've had it since brand new). Doesn't accelerate as smoothly as it used to before that. Dealers have been completely useless. I'm at 37k now and will be getting out of it soon.

 

What he said.

 

Have you changed engine air filter? Fuel filter? Plugs? While some would say it is premature on the plugs, we don't know what kind of lfe your car has led. Lost of dusty dirty conditions would contrubute too. Also try some Techron fuel injection cleaner. Costco has this fuel tank additive.

 

Fuel filter is not a replaceable stand alone item. Air filter may be dirty enough to affect performance, but i doubt it. Spark pugs at 25K miles? No way they are bad. He is not reporting a misfire, and he has had his car to 100 mph. for up to 100 miles. He knows what kind of life his car has had, and it matters not to the spark plugs.

 

I’ve had that.. just returned my car. I’ve noticed this summer when it’s 100 f the car sounded rough once on the highway it gets smooth. Once in the traffic it felt like a diesel car. I didn’t like that at all. I certainly don’t remember being it like that when I spent the first and second summer with it. Also it would hesitate to accelerate in the slow traffic like 0 to 15-20mph. Once over 25 it felt normal. At first I thought maybe gas was an issue and I did use premium for the last two weeks. But it didn’t really change anything. I would still feel the rough idling and hesitant on accelerating.

 

The VQ loves cold weather. Runs much better in cool temps. My LS1 powered GTO would severely suffer from Heat Soak.

 

High humidity also sucks since water molecules take up space where atmosphere would be swallowed instead.