Higher RPM driving with a cold engine ?

[MuranoSV]

I have 2011 MO and had two winters but didn't notice this.
Toronto had a little cold (-8 ~ ~5 C) weather in this week. When I drive my MO while the engine is cold for the first 5~10 minutes, the engine rpm at 60~70kph keeps around 1800 ~2000rpm and it doesn't drop to 1100~1200rpm. After the full warm up of the engine, MO runs at normal rpm range. Is it normal, right ?

[Halwg]

I'm pretty sure mine does the same thing. I do know the AWD works great on slick and snowy roads. I had the unfortunate experience of having to drive through winter Storm Euclid coming back from Christmas with family. I felt very secure and never spun a wheel.

[nighttalk]

I think that's normal.

I am in Vancouver, a little bit warmer here, 0 to 5.

In the morning, the RPM is higher, and using a lot more fuel.

After the car warm up, rpm dropped, and smoother, too

my murano also a 2011, 2nd winter now. =D

[njjoe]

Yes, it is normal.

-njjoe

[micco]

yup normal, as you noticed until the normal operating temps are reached.
- i'm in winnipeg btw, so i can confirm

[MuranoSV]

Thank you for the replies. No worries, now.

[UncleWillie]

Normally this feature kicks in for me once the temperature drops below 3 °C.

There is a 'trick' though. If the engine is restarted in a minute or so this feature seems to be getting overridden by the computer and the vehicle could be driven with low RPM at low engine temps.

I noticed this happen even with the outside temperatures way below zero (°C).

[2young2retire]

I kinda-sorta think this is to protect the transmission until the fluid warms up.

[smoothrunnings]

Originally Posted by MuranoSV

I have 2011 MO and had two winters but didn't notice this.
Toronto had a little cold (-8 ~ ~5 C) weather in this week. When I drive my MO while the engine is cold for the first 5~10 minutes, the engine rpm at 60~70kph keeps around 1800 ~2000rpm and it doesn't drop to 1100~1200rpm. After the full warm up of the engine, MO runs at normal rpm range. Is it normal, right ?

I have the same problem, though if you actually take the time and read your owners manual Nissan will suggest that you let your MO warm up at least xx seconds or minutes before taking off. Mine is 30 seconds but I wait 2 to 3 minutes. Most people jump in their cars, turn them on, then drive off without letting the engine and the oil heat up a bit. It's no wonder they are placing their cars every 3 years!

So lately with Toronto's temps being quite low, after 3 minutes the RPMs are still high but it only take me about 1/2 KM until everything is okay. I am not sure how long you go before the choke turns off, that's what most engines do when it's cold enable the auto-choke.

[KJSmitty]

Originally Posted by smoothrunnings

I have the same problem, though if you actually take the time and read your owners manual Nissan will suggest that you let your MO warm up at least xx seconds or minutes before taking off. Mine is 30 seconds but I wait 2 to 3 minutes. Most people jump in their cars, turn them on, then drive off without letting the engine and the oil heat up a bit. It's no wonder they are placing their cars every 3 years!

So lately with Toronto's temps being quite low, after 3 minutes the RPMs are still high but it only take me about 1/2 KM until everything is okay. I am not sure how long you go before the choke turns off, that's what most engines do when it's cold enable the auto-choke.

Any delay over 15-30 seconds after starting is wasting gas. Your oil pressure is near instantaneous, oil flow even at the top of the engine starts at 5-10 seconds, oil is thrown on pistons and cylinder walls in the same amount of time. Waiting 2 or 3 minutes is just getting you to work that much later and with less gas. :-)

Yes the Mo manual does state 30 seconds. I could near guarantee 15 seconds is fine due to they place a 100% positive safety margin on suggestions like that. The 2-3 minute following statement references not to shut it off until its ran for 2-3 minutes etc., - IE, short trips when cold causes moisture and other issues within the crankcase.

Either way, a high idle during cold starts is completely normal.

Cheers

[smoothrunnings]

Originally Posted by KJSmitty

Any delay over 15-30 seconds after starting is wasting gas. Your oil pressure is near instantaneous, oil flow even at the top of the engine starts at 5-10 seconds, oil is thrown on pistons and cylinder walls in the same amount of time. Waiting 2 or 3 minutes is just getting you to work that much later and with less gas. :-)

Yes the Mo manual does state 30 seconds. I could near guarantee 15 seconds is fine due to they place a 100% positive safety margin on suggestions like that. The 2-3 minute following statement references not to shut it off until its ran for 2-3 minutes etc., - IE, short trips when cold causes moisture and other issues within the crankcase.

Either way, a high idle during cold starts is completely normal.

Cheers

You do realize your reasoning is invalid. Do you know what happens when your MO choke is engaged? If you don't let your MO warm up before you pull away and the choke is engaged you'll be burning more gas than if you waited for to warm up and pull away, plus it puts less stress on the engine overall.

This is why people who drive their cars, trucks, SUV and CUVs properly should be able to get 20 years or more out of them before they are deemed no longer road worthy (usually because by then the rust wins!).

If you are that worried about being late for work, stop being lazy and leave your house earlier! You should way be ready for the conditions outside before you leave your home no matter your schedule...smirk

[Halwg]

Guess what. Fuel injected engines don't have a "choke". They have a throttle body and are controlled by the computer which regulates timing and air/fuel mix. So you are completely off-base with this one.

Someone, possibly Billarf, who knows more about the operations of a fuel injected engine than I do, can explain this to you in more detail.

[KJSmitty]

Originally Posted by smoothrunnings

You do realize your reasoning is invalid. Do you know what happens when your MO choke is engaged? If you don't let your MO warm up before you pull away and the choke is engaged you'll be burning more gas than if you waited for to warm up and pull away, plus it puts less stress on the engine overall.

This is why people who drive their cars, trucks, SUV and CUVs properly should be able to get 20 years or more out of them before they are deemed no longer road worthy (usually because by then the rust wins!).

If you are that worried about being late for work, stop being lazy and leave your house earlier! You should way be ready for the conditions outside before you leave your home no matter your schedule...smirk

Great reply,
Normally I wouldn't even respond yet you may want to gather a bit more experience and factual knowledge before stating someone's post is invalid. I merely stated a few facts and my opinion. Has nothing to do with needing to leave for work a few minutes earlier or being lazy or ready for the conditions - good grief. It has everything to do with understanding the specifics behind today's computer controlled combustion engines and what's really taking place in the engine and transmission whether cold or hot.
I was a dealership / Nissan, Honda, Pontiac, Oldsmobile, Cadillac and GMC Tech for over 8 years (in a bordering state to Canada thus I know all about cold operations/weather driving. Spent 26 years there. :-)). I don't claim to know a massive amount about everything automotive, but I do know I have forgot more than many do know. So, in an attempt to not come off as personal as you, I will end by stating I contribute to car enthusiast forums for one reason and that is to hopefully spread some "fact" and my experience in hoping it contributes to someone's issue.

There is nothing wrong with letting your vehicle idle for however long in the morning to warm up prior to driving. Me, myself and I let it idle for approximately 15-30 seconds prior to backing out of the garage. Nothing wrong with that either. No, I'm not smirking.

And seriously, stay warm. I had to move south, no longer enjoy those temps for extended periods.

Cheers