I would not, for a couple of reasons:
1.. It may not work at all.
Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards can be very sensitive to this.
This is more difficult when 4 sticks are involved.
That is why ram vendors will NOT support ram that is not bought in one kit.
2. If you CAN get ram of different speeds to run, All will run at the lower of the two speeds so 2400 speed will be of no value to you.
3. There is little real value in faster ddr3 ram. The benefit amounts to perhaps 1-2%
Haswell is only dual channel, the presence of 4 sticks does not make it quad channel.
If you already have the ram, of course you can try it and see how it works out. Often adding voltage to the ram will get 4 sticks to work.
My suggestion:
Buy a 2 x 8gb kit of DDR3 1866 replacement.
Sell your old kit or keep it as backup.
If you go cheap and buy 8gb as an addition, it may not work and you are still facing a 16gb kit purchase.
Ram is cheap enough, and there IS a performance benefit from more ram.