If you want help you are going to need to provide more information. Your ping spikes are to one address, or multiple? Are you on WiFi? Have you bypassed the router? Changing your DNS will help with lags when connecting to websites, and should have no affect on ping times. There are hundreds of possibilities ranging from defective network equipment to a virus.
The more information you provide the better chance someone will think of a test that will help you determine your problem. There are also 4000+ threads dealing with ping spikes, I'd bet money that most have some great suggestions that you have not tried.