01 Q45 4.1 Liter Cold idle

[roaddog]

Hello,

Could someone please inform me on what normal cold start up should be on this motor. I have never owned a Infiniti till now and I do not know if this is normal.When car is started in morning engine idles at around 1400-1500 RPM and stays there untill engine warms up. If you tap accelerator to kick off high idle nothing changes. Once engine begins to warm up say 4 to 5 min idle will very very slowly begin to drop. I have always owned American cars and maybe after 1 min idle would drop or if you tapped accel it would kick off.

Thanks

[maxnix]

It's not a Cheby.

Don't drive until it achieves operating temperature.

[oldmako]

On an Uhmerican car (and older imports) tapping on the gas pedal used to allow a mechanical cam to swing out of the way once the engine had warmed up a bit. That cam mechanically repositioned the throttle linkage to force a higher idle speed. Pretty ingenious and foolproof way to assist in cold weather starts. There is no such low-tech mechanical device on a Q-bomb. Hal and the rest of the microprocessors have taken over the ship. "Daisy, Daisy, give me your answer please....." (name that movie).

The following is my technique for cold starts. After cranking it, I let it idle for at least a min or so before driving off (if feasible). Good time to plug in the iPod, hide the reefer, adjust gangster lean, etc. In extremely cold weather, I follow this more rigorously and TRY to give it more time to warm up. I also drive it gently until the needle is at least one quarter throw on the coolant temp gauge. By gently I mean easy application of throttle and never more than 2000 rpm until it warms up. It never takes more than a 2-3 few minutes to get to at least one quarter, and about 4-5 to get to half. Of course, if you don't plan on getting the max life out of the car, you are free to wail on it at your leisure.

On my 99 Q41, the trans brain will prevent normal shifting until it warms up as well.

Your mileage may vary.

[jimbyjimb]

I'm envisioning your Avatar gangsta leaning while reefing and bumping the gangsta beats doing 35 on the freeway. LMAO. Maybe Cheech and Chong are in the backseat passed out from over-reefage and the car is littered with Dorito bags, 7-11 hotdog boxes and empty Big Bear 40's. The back end is squatting, the front end is lifted and the 22's are spinning. I like this imagination stuff.

[maxnix]

I guess if I had some stash I would want to know where his compartment was. I think RR has a humidor option.
Modified by maxnix at 3:50 PM 5/28/2009

[jimbyjimb]

Wine coolers and nifty umbrellas in the door too. Too bad real Seattlites never use umbrellas. Imagine how awesome it would be to rock an RR umbrella.

[maxnix]

I used them, when it was really raining, not just the usual 105% humidity.

[jimbyjimb]

Ah, but were you born and bread or a live-in foreigner?

[maxnix]

From a foregn country. Didn't have moss between my toes.

Loved to watch the natives suffer in a real downpour, though. I've seen cats with more sense.

[BadQ45t]

To get back to the guys original question, that is not normal. I have a 97' wtih 91k on the odo and wait not one second to warm up.

My older 300ZX sort of does the 1500 rpms and than warms up and idles at normal, but you've got some type of problem going on there. I wouldn't be able to tell you exactly what but for sure there is an issue. The Q shouldn't need any warm up at all....the transmission on all Nissan's do not shift into 4th until warm (my 85' Maxima did that too).

[Infinitiguy19]

Actually ALL vehicles with a internal cumbustion engine need time to warm up, it may not be the the whole engine that needs it. But the oil and transmission fluid is designed to work when the car is fully warmed up.

Correct me if I am wrong.

[elwesso]

FOr the OP... Usually most V8 will idle cold around 1250 RPM and then slowly drop off... On all our american cars they idle much less when cold, so I understand the concern..

I wouldnt be too concerned if it still idles smooth at 650RPM or so when fully warmed up!

[BadQ45t]

I have actually read a number of articles on this and they day that 15-20 seconds on newer cars is enough. Again, my car comes out of a garage in California so no sub zero temps (maybe 48-50 in my garage max cold)..if I lived in Minnesota I'd be more likely to warm up.

[elwesso]

The main issue with warmup time is that the oil doesnt do a very good job of lubricating things until it gets to 100F.. Why BMW has the variable redline that will not allow you to rev the engine too high until the oil gets to the proper temp.

I dont know what kind of correlation this has to overall engine life but the point here is the longer you drive with the engine oil temp under 100F the more wear occurs. Of course it depends on the number of cold cranks..

In the summer time I dont give the car too much time as it takes me at least 2 minutes to get out of my neighborhood, so im basically idling out of my neighborhood and then i take it easy until its at full temp.

[maxnix]

I have actually read a number of articles on this and they day that 15-20 seconds on newer cars is enough.

And who authors these "articles" ?

The fact is, every mechanical device is designed to work in particular conditions at particular temperatures. Whether one lives in Tierra del Fuego or Saudi Arabia, the designed operating temperature is the same.

If your car is not operating correctly when cold, think that might be a clue?
Modified by maxnix at 9:43 AM 6/2/2009

[Q45tech]

Driving away before the engine reaches operating temperature [174F coolant] is a sure method to make sure the engine bearings and rings won't last 400,000 miles.

The condensation moisture doesn't evaporate out until the oil reaches ~~170F.

On ODBII [96 and later] the warm up HIGH idle is shorter in time but not much you still need to wait until ATF reaches 140F+ for 4th gear availability.

All fully explained in FSM.

[Alowther]

Definitely starting is the one of the highest wear impacts on an engine.

Worked with a guy who worked on pipeline compressor stations back in the day. Their genset was a chev 350, and ran 24 hours a day, they would change the oil by dropping the drain plug while pouring in the new oil at the same time, all while it was running.

These engines would last 4 years +, without a rebuild, running 24/7.

Thats 35,000 hours. The driving equivilent of that at an average of 30 miles an hour is 1,050,000 miles. As nobody sees that on a chev 350 in auto applications, it demonstrates the amount of wear on the engine during starting. (Results are a little skewed as the engine was also at constant RPM's but you get the idea).

Totally off topic, but interesting. Its a good reminder for me to let the poor girl warm up and to run synthetics in the winter during the -40's up here in the north.

[paranoidjack]

Not too off topic, and thanks for the information.

I used to go to McGill, and I had to install a block heater - I feel you on the cold starts!

[elwesso]

Definitely starting is the one of the highest wear impacts on an engine.

Worked with a guy who worked on pipeline compressor stations back in the day. Their genset was a chev 350, and ran 24 hours a day, they would change the oil by dropping the drain plug while pouring in the new oil at the same time, all while it was running.

So how did they change the filter??

[paranoidjack]

So how did they change the filter??

Quickly!

[BadQ45t]

My 1984 300zx still runs fine 25 years later, but point taken, Iwill pause for 2 minutes before pulling out, but seriously did read in a newspaper or somewhere that said newer cars at least do not need the 3-4 minute warm up that they did in the past.