I've noticed an oddity upon starting my 2014 XKR. The car seems to go through it's own routine. I'm not sure what it's doing, but the sounds and the routine are exactly the same, every time, Dynamic mode on or off.

When I first start the engine, it runs at 1300 RPMs for exactly 52 seconds. After that, the RPM needle begins to drop, and after another 6 seconds or so, it's purring at 600 where it should be. Every. Single. Time. Somewhere in this routine there's also a sound like something winding up, then winding back down, as if making sure everything's all good before we go. Having noticed this, I have been waiting for the routine to end before I put the car into gear. Not a big deal, but I don't think I've ever before waited for the car to seemingly be "ready" before I took off.

I don't know if this is normal or not, but I'm curious. Has anyone else noticed this? I don't remember anything quite like this in any other car I've owned or driven. Maybe I've been driving wrong my whole life by jumping in a car and just putting it in gear and moving along...or perhaps I'm just paying attention because this car is new to me. Either way, I don't ever remember a car doing that before.

 

All fuel injected cars act like this. On a cold start the ECU is in "open loop" which enriches the fuel/air mixture similar to a choke in a carb engine. As the heaters in the O2 sensors heat up the system then goes into "closed loop" which the ECU sets the idle parameters. By then the oil temp should start to go above ambient temp. On all of my FI vehicles I start and wait until the engine goes into closed loop and then drive away. My 2 cents here without going to deep into how the ECU functions.

 

Yep it was the same in my XKR (not sure about how long exactly) and the F Type seems to take longer to drop to idle, though the 4 pot drops to idle after a quite short time. If you drive it then stop for a half hour this process will be a lot shorter, so it seems to be engine temp related.

I dont get the wind up wind down noise, but I do get a metallic noise like something is opening maybe halfway through the routine.

 

Hi
I have a 2014 XKR and haven't noticed anything unusual but will check tomorrow and let you know what I find.
Regards Rick

 

Of course mine does the same, although I've never had an inkling to actually time it.

 

It's trying to go closed loop but needs O2 sensors hot and a few other things. Once CL it can do roughly what this pic shows OnBoardDiagnostics.com - Engine Basics (reading the sensors many times a second and adjusting the actuators as needed).

 

I did make a 15 minute stop earlier this evening, and yep....after I got back in the car, there was no "52 Second Routine"...which makes sense since everything is still warm.

Thanks for the explanation and the diagram!

 

XK does the same thing, at least the high to low RPM. The wind up/down is not something I have but maybe a loop in the supercharger.

 

The '15 XF does the same thing as everyone is mentioning, as does my '08 XKR.

 

I'm not aware of any need to wait for the engine to go into closed loop with the slower tick-over before driving off - I don't, but I drive relatively sedately until the engine has had chance to warm up to allow the oil to circulate properly.

Mind you, my days of disappearing over the horizon in a cloud of dust, with tyres squealing and engine screaming were left behind so long ago, it's difficult to remember if I ever actually did do that!

 

I also believe there's no need to wait, though it's not long. I never bother to wait but have "only" done 66,000 miles over the last 8 years so maybe I'm risking a problem... eventually?

 

I don't believe you need to wait any specific time . It's just like any other engine and you can jump in , start it and drive away. I do it just to get the fluids running but I also put the top down at the same time it is at a higher rpm. Just a quirk of mine.

 

Yeah, I figure if it was important to wait, after 30+ years of driving, somebody would've told me before now....lol. Never waited in any other car and never had a problem. For whatever reason, it was just really noticeable to me in this car.

 

I also experience the "warm-up" period with my 2010 XKR, with the elevated RPMs at the start, settling down after half a minute or so. I, generally, wait it out, not out of concern for oil circulation, but because at the elevated RPMs the shifts between gears (mostly first through third) are much harder, especially since I use the paddles most of the time. Once down to 600-700 RPMs, shifting gears is much smoother.

 

I don't actively wait, but I start and then put on my seatbelt, back out of the garage, then usually wait to see the door coming down before I proceed. In that time it settles. There are times I am in a hurry and shorten that process and have no concern it is bad for the car.

 

It's not really a warm up period. Ford found out on the early 4.6l engines that they had a noticeable piston slap sound on a cold engine at idle RPM so across the board they run the engines around 1k to get the oil splashing and flowing well. No load moderate RPM is healthier on a cold engine that barely idling with little oil flow. I let mine run until it drops out of fast idle since it's easier on the drive line. Gives me an opportunity to relax and smell the leather before driving off into the chaos.

 

That's good to know. I dont like the lurch putting it into reverse or drive during the fast idle - it feels like it shouldnt be done but maybe it is psychological.