I have reviewed several surging posts and am pretty sure I have the issue resulting from air in the coolant system but wanted to post a video just can’t seem to get it to burp or whatever it is that needs to be done. I had to replace a leaky heater hose which required removing the intake. I of course flushed the system with fresh water and gently used some air pressure to get as much old coolant out as possible. Upon reassembly and restarting I am getting a surging as can be seen in the video. It seemed to do it more or less right away, but definitely settled into a rhythm. Thoughts?!?!

 

Since I can’t delete this I figured I’d post my solution. I crossed two of the tiny vacuum lines when putting my intake back on and the EGR valve was opening immediately, and I assume whatever I put the EGR valve vacuum line on was also not happy. Once I figured I did that and switched them it runs perfect!

 

When reading your first post I was thinking vacuum leak. I had a similar issue and turned out to be a leaking vacuum hose to my power steering VSV. Glad you found yours.

Jake