I was inspecting my new (to me) 2006 IS350 and I noticed something unusual with the overflow reservoir... there appears to be a lot of buildup around the cap. Does anyone have any ideas why this might be? The car drives fine and did not overheat at all on the 9hr drive home. Thanks!

 

It's normal wait till it cools down and recheck the level. Make sure it's near the full mark. If it has too much overfill you will see it more pronounced.

 

normal stuff

 

 

Thanks guys, I'm glad it's normal. I just figured I would ask.

 

yep normal.
the reservoir isn't completely air tight so when hot coolant overflows into it some "steam" gets pushed out creating this...just wipe it clean when the engine is cool.

 

Something else you've probably not noticed is that the "overflow tube" there leads to nowhere. It just empties out on top of the electrical fan surround. LOL! Silly Lexus!

 

Genius! I also noticed that the surround is cracked on the electric fan surround, I wonder if that is related.

 

Not likely related; but worth checking into to see if anything else in the front end there might have damage.

Any previous front end accidents?

 

The previous owner claims to have bumped something once, which is why the grille is messaged up and the bumper isn't sitting 100% correctly. I didn't see any other damage until I saw the electric fan shroud. It doesn't seem concerning though.