# cold engine revving



## jhyukkang (Dec 28, 2011)

hi, i have few questions today. before that, i have 2010 sentra 2.0S, with CVT

1. today, I started my car drove out to main street in my neighbor. (this took maybe 30 sec or a minute). and i all of sudden decided to pretty much floor it to go fast. it was 45F outside temp. and considering that it was 30 sec to 1 min after cold start. i was accerating at 5k rpm for like 3 - 5 seconds. could i have done any damage to my car? 

2. when i start the car in the morning, i sometimes, turn off overdrive or put shifter into Low whenever i come to a stop to warm up the engine faster. (so i use less brake by engine braking and higher rpm to generate more heat without using extra gas). is this a bad thing to do?

3. lastly.. when I am costing at like 30 or 35mph, with my foot off the pedal, i hear like an airplane engine high pitch sound as car slows down. is this normal? also when i give a gas a very light touch, I hear 'clank' then feel car accelerating. is this normal as well? 

thank you very much for help. please correct my errors.


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## nissanpm (Dec 28, 2011)

*not to worry....*

1. I've worked with nissan for a while, ive never heard of anyone causing any damage to any of the new model vehicles by driving faster after starting, most of the time, right after starting the vehicle it takes just seconds for the oil to reach the top end
2. Im not sure about hurting anything by rev'ing high and downshifting, if there was a problems doing this, nissan would have regulated this option or installed a failesafe function for detecting a problem when doing this. 
3.and lastly, your transmission is know for noises that are considered normal characteristics of the trans.. CVT had problems in most models and so they provided customers with an extension of warranty and your vehicle is no exception, the whinning is normal to a degree, if its consistant while accelerating and at slow speeds, then you might wanna have it checked out by the dealer.


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## jhyukkang (Dec 28, 2011)

thanks for quick reply. so I shouldnt worry too much about it. also to conclude, moving shifter from D to L, or L to D while car is in motion is ok right? ofcourse I dont move it from D to L when Im on freeway, but when I am going maybe 25, 30. I put it in L for engine break, and it goes up to 3.5 - 4k rpm.


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## nissanpm (Dec 28, 2011)

moving the shifter should be fine while in motion, most models will not downshift until the trans. control module knows it will not be redlining.


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## jhyukkang (Dec 28, 2011)

ok I see. just one more if not too much about clacking i hear at around 30, 40 mph.
as i said, when i give gas pedal a light tough, i feel and hear light clank. I will explain this by using bike chain system (not motor bike).

So let say you are riding ur bike, not pedaling because u already have some speed. when you pedal it back wards, chain just rotates with ur pedal right? like stepping on gas pedal on neutral comparing to the car. on bike, you all of sudden pedal it forward, and you hear clank, (chain and gear catching with wheel and transfering power to wheels) or engaging. this is how i would describe the feeling and sound when i give my gas light touch. i dont hear is when im more than 45 mph i believe. maybe because of rpm would be higher at that point and other sounds blocking it. 

is this normal? the sound is very light 'clack' or 'tick'. this happens when rpm is between 1.1k and 1.3k.


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## jhyukkang (Dec 28, 2011)

back to my original question number 1. i made a mistake.
i said i accelerated at 5k rpm, i think it was like between 5.5k and 6k. when temperature gauge showed no bars for engine temp.


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