Hey NAM,
I've been loving my 2015 F56 MCS manual for 3 months now but it has some quirks which i don't suspect are normal, so I thought I'd ping all of you to help me determine if I'm crazy, particular, or sane!

I drive a lot. 180 miles a day, all highway. Almost all at 80+MPH.

I've noticed that the car surges at constant throttle. It does it both with cruise control on, and without. It is especially worse now that I have a Cravenspeed intake, and is very noticeable when going up hill.

Is this normal for these cars? I have an old Xterra that has the worst cruise control in the world, and it surges like this. But only when on cruise control. The F56 does it when driving by throttle.

So, is it possible that the gas pedal is going? It happens worse in ECO, medium in STD, and less in Sport. I is noticeable enough that when I set cruise control, i have to drop it into Sport mode.

I'm handy but don't have anything to diagnose a gas pedal issue yet. These are drive-by-wire, right?

Thanks in advance.

 

Could be lots of things, not normal at all. Fuel quality, air leaks, etc. etc. I assume it isn't throwing check engine lights. Have you put an OBDII reader on it? Stop by a quality auto parts shop that can do a quick scan to see if anything pops up.

 

I do have an OBDII reader, so i'll hook it up this weekend and check things. Maybe i can monitor throttle position and see if it's wandering under constant throttle. No reason why I should have an air leak, but i'll check to make sure there's nothing there. Fuel changes regularly, as i have no preference to station and it occurs regularly.

Anyone have any idea if the throttle sensor is known to go bad? I would think it would be a pretty reliable part given its importance!!!

One other thing that popped into mind- when shifting in sport mode at high RPMs, the revs don't drop fast. it's almost as if the throttle (pedal or valvetronic) is slow to react to the lift off. Is THAT normal? I'd think not. I am due for an oil change, though.

Thanks.

 

Another thread exists about this problem. I also have it anytime going over 70-75 mph. So far no one has come up with anything on it.

 

Thanks hadjikong. Do you have a link to the thread? I want this fixed before I install the JB4.

 

Yup here you go