Why does my ping increase after a few minutes of resetting AirPort?

Question

I connect various phones and my Macbook Air to WIFI using my AirPort Express. I have been plagued with WIFI and ISP problems and recently upgraded my modem to try and fix this issue that persists to this day. I feel like I have narrowed down the problem to my AirPort Express.
After resetting my Airport everything appears to be running smoothly. My download/upload speeds are adequate, I have a very strong WIFI signal, all is well. When I go to play online games I notice an increase in my ping within 10 minutes of resetting my Airport. It happens fairly abruptly - it is not an incremental change. For example I am usually jumping from ~100ms to ~450ms. This happens on multiple servers and can't be tied to one host.
After resetting my AirPort my ping goes back down to normal but jumps up after a few moments. I have my Arris modem set to bridge, and I've tried connecting to the 5GHz channel through the router and there doesn't seem to be any difference.
This problem started a month or so ago. The AirPort has worked absolutely perfectly for a couple of years now. It is really only the ping in online games that seem to be effected – my download/upload speeds are running well which has me stumped.
AirPort Express
Version 7.6.4
Serial number C86HV4YPDV2R
I really appreciate any help! I am out of warranty with the device to call apple and I've spent more than a lifetime on the phone with TWC.

Answer 1

Wireless is extraordinarily complicated. It is more a wonder that it works that doesn't.
Two follow up questions. First, I have taken both the phones in the household off wifi as well as my Roku and that didn't make any noticeable differences.
It is worth a try.. it is wireless after all.. voodoo in another medium.
your answer doesn't really help with two issues. My computer used to connect with no ping increase before this sudden change and why does this change start happening after a few moments of clarity and then skyrocketing pings?
How old is your Express? Anything more than 3 years can suffer due to build quality.. apple is no different to other brands now. A sudden change can indicate poor internals.
7.6.4 is lousy firmware.. test with 7.6.1 if that is possible. (newest ones may not downgrade)
I personally have heaps of Extreme and TC but avoid the express.. it is expensive for what it is.. a very low end wireless AP that can double up as a router at a pinch.
If you have an old Express that you upgraded the firmware.. you may not have noticed the upgrade coincided with the poor pings.. but it can happen.
Also Mavericks.. if you upgrade installed mavericks it can have dire effects on the wireless.. even the latest update to Mavericks has been causing wireless issues. Mavericks and networking is somewhat akin to tin cans and wet string. With the string fraying.
So reset to factory.
Downgrade the firmware.. then reset to factory a second time..
Test it with short names, no spaces and pure alphanumeric.. NOT apple names.. since mavericks changed to SMB networking from AFP in previous versions.
Downgrade firmware by holding down the option key whilst you select version number. Pick from the list that will appear.
Test close to the Express..
Test with no wireless security.. remember it is a test.
Run the wireless diagnostics on the computer to see if it shows anything.
About Wireless Diagnostics
The reason for increase in ping times, can be link speeds dropping, WMM failing.. as it seems to .. or just plain old bad drivers.
I have made huge improvements in things like latency in routers that allow actual settings on the wireless to be changed.. packet size in particular.. one serious issue here is Apple have not given us access to any settings.. in airport particularly but even in the Mac.. this stuff is hidden from end users.