I have a new 2016 F150 with the 5.0,in the mornings when I start it the RPMS are @1000 and then after about 10 minutes it idles down to about 750,will it hurt the transmission to take off after about 5 minutes when it's still at 1000 RPM?

 

I could be wrong, the fast idle serves the purpose of warming up your catalytic converters to make them more efficient.

The fast idle should shut cut out when you shift out of park.

 

This is normal and gets asked often. A quick google will tell you why if you're interested in details. As for hurting the transmission, no, but don't drive it hard until both the engine and trans are warmed up.

 

I've noticed the same thing with my truck (also a 5.0). I wondered the same thing as you, but then I just figured that they wouldn't make it idle that high if it was going to cause transmission problems. They must have taken it into account.

 

Y'all every vehicle that I've owned does this. It's a cold start. It needs to rev high to get warmed up. If after you ran say 15 or so minutes and shut off the engine and restarted it the idle will be lower. But if your vehicle sat longer, say overnight, then it will high idle again. Totally normal.

 

mine sits at 1300 for about 5 mins then backs down to 1000 for another 5 mins before idling down to 550. these are all numbers from Torque Pro.

 

These '15+ do it for a longer time than the 14's did. I'm sure it has to do with EPA #'s. I used to let my '14 idle down (about 45-50 seconds) before taking off -- now I just wait the 30 seconds or so in my '16 and go. Take it easy until she's warmed up though.

 

I do realize this, but my old 5.4 did it for a much shorter time, and I could tap the throttle a bit and it would idle down if I didn't want to wait.

 

Thanks for all the replys,just wanted to make sure the engine computer was working right and putting it in drive at 1000 RPM every morning was not going to hurt the drive train.

 

Well, technically it's not running high idle to warm up, it's running high idle to keep from stalling.


When you first start a cold engine, it will run rich (remember the choke on simpler engines to get it started?) to get good combustion in the cold. But because it's running rich, this affects the combustion since too much fuel can make an engine run rough from wetting the spark plug or even stall. The engine compensates for this by raising the RPM. This is also why your exhaust can smell like gas when you're starting up in really cold temps. Once the engine warms, it leans out the mixture and is able to lower the RPM's again since there's good combustion.


This is also why they say idling your engine to warm it up for a long time uses more fuel than letting it warm up a little bit and then driving. The ECU leans out the mixture quicker by driving because the engine warms up faster. Idling and running rich for longer obviously uses more fuel.