Ive noticed it a couple of times but I thought that I would ask before I get too worried. Im not sure if its a big deal because it might just be that its not warm enough for the thermostat to open yet, but when I take the cap off the overflow it releases the built up vacuum. I haven't had any overheating issues like some have had on here but just want to ensure that I won't.

Rad cap is not releasing pressure, you need to replace it. I had mine warrentied a few weeks ago for the same thing.

OH is a whole different issue, not cap related.

x2

the surge tank cap is not letting air back into the system creating a vacume as it cools down. painter

Thanks guys I already bought a new cap so it should be fixed