berliner

..does it idle at a high rpm, and then after 30seconds go down?

the reason why i am asking this is because i just recently bought a 09 Infiniti Fx50S and it idles at 1500rpm when i start it and then after 30seconds it goes down to 800rpm.

people on infiniti forums have told me that this happens to their cars also. i find it quite an inconvenience that i have to wait 30seconds until i can move the car. never had this problem with my 4cylinder cars.

ek9vboi

iTrader: (3)

If it idles around 1-1500 then its normal IMO. Sometimes the car does it (cold starts) to warm up the motor.

BTW if this was really a problem, no one would buy the car. You are fine to drive the car, it would actually help warm up the oil, rad. fuilds/etc

Yang1815

iTrader: (1)

I think the 3GS does a similar thing too. Not sure if it's 30 seconds though.

whlkev

It's like that in virtually every car I've driven?

usually 15 seconds or less...

19psi

that's normal for many reasons, a couple of which are, emissions (faster warmup is better for emissions) and cold starts. when you first start the engine, the mixture is richer, richer mixtures make for higher engine speeds.
it's good to wait for a minute or so when first starting the engine before moving anyway. this allows the oil to warm up and properly lubricate the engine. if you just fire it up and go, the oil can't do it's job fully becuase it's too cold (thick) unless you're running some 0-20w synthetic.

berliner

thanks for the info guys. in the owners manual i actually found this;

4. Warm-up
Allow the engine to idle for at least 30
seconds after starting. Do not race the
engine while warming it up. Drive at
moderate speed for a short distance
first, especially in cold weather. In cold
weather, keep the engine running for a
minimum of 2 - 3 minutes before
shutting it off. Starting and stopping
the engine over a short period of time
may make the vehicle more difficult to
start.

19psi

now you know!

Modeler

You don't have to wait at all after starting the engine. It makes no difference what the idle RPM is.

19psi

you don't have to wait at all but for longevity's sake it's a good idea to do so. it's just better for the engine to have warm oil before it gets loaded.

Modeler

That would make a difference between the car failing after 200K miles vs 210K? Common, this is not the 70s!

19psi

i thought everybody knew by now that cold starts cause the most wear on the engine. it then stands to reason that cold loading of hte engine causes more wear as well. just listen to the engine when you start it at cold temperatures. compare the sounds of it when it's cold to when it's warm. all those little sounds go away once the oil is warm.
but hey, i only work on high end cars for a living and have been to extensive training for every aspect of a vehicle's systems. i don't know much about cars.... do what you want.

berliner

of course i knew that you are not supposed to push the car until the engine is warmed up and well lubricated. but honestly i really dont recall my 4cylinder cars (which is what i always had) to idle at such a high rpm when i started them. 1500rpm and then dropping to 800 after 20-30 seconds is something that i never had in my previous, way less powerful, cars

i do wonder if it idles at such a high rpm when i start it because it only has a few hundred miles on the odometer.