2008 Tundra SR5 4.7 leaking coolant

I’ve been leaking coolant in my Tundra, took it in to get looked at and they said they found a leak with an O ring. They replaced it. And said that should fix it. Well I just popped the hood and opened the oil cap. And this is what I found. (I looked for milky liquid on the oil cap and radiator cap before I took it in and found nothing…Now today I did…what could this mean..

 

That milky oil on the cap can happen after short drives. Just clean it off.

 

The white goo is a sign of moisture best case scenario is driving short trips worse case would be a blown head gasket. I would check the oil dipstick to see how that looks and clean the goo off the oil cap and see if it returns

 

Checked the oil dip stick every day, and have found nothing. And I cleaned the oil cap the day I posted this and hasn’t seen it return yet.

 

Has your coolant level been normal since the o ring replacement?

 

As far as I can tell. It’s gone down when it gets cold and goes back up once I’ve run the truck for a bit. Before it was going down regardless of running or not running it.

 

The rise and fall you're seeing in coolant is fairly normal. If you see it drop way below what it looks like when it's cold you know there is a bigger problem than that o ring. Im guessing it's a pretty good assumption that what you saw in the oil cap is a common cause of short trips.