I am currently running bitcoind v0.16.0.0 on my macbook (osx 10.12.6) and the initial sync time is really slow. I'm syncing at roughly 88 blocks per hour which would mean it would take another 2 months to sync up.. In the activity monitor it looks like bitcoind is using only 3% of the CPU time. Could this be the issue? Is there any way to speed it up?
Yes there is. The bottleneck is I/O speed and normal HD drives are really slow. You can move the chainstate directory (around 3GB) to an SSD. If your laptop doesn't have an SSD you can use an SSD thumb drive.
There are instruction how to do that in the wiki. I did that using an usb stick SSD and the whole chain synced in a liitle less than 12 hours.