When I was looking around under the hood of my 05 I noticed that the coolant was over the max mark on my overflow tank. The engine was cold and I opened my radiator cap. I hear a suction noise and noticed that my coolant was about 2" low in my radiator. I took coolant out of my overflow tank unit it was at the max mark, and then I filled my radiator up, replaced all the caps. I started it up and I notice that the tank fills exactly to the spot it was just At. I haven't yet checked the radiator but I assume it's 2" down. I'm going to bring it to the dealer tomorrow but I was wondering if anyone had a though about what it could be?

Here is what the manual says:

Check the coolant level in the reservoir when
the engine is cold. If the coolant level is below
the MIN level, add coolant to the MAX level. If the
reservoir is empty, check the coolant level in the
radiator when the engine is cold. If there is
insufficient coolant in the radiator, fill the radiator
with coolant up to the filler opening and also add
it to the reservoir up to the MAX level.

I am not the world's expert on this (whoever is chime in), but I checked under my hood (cold engine) and found that the coolant reservoir was MAX, and looked in the radiator, and could not see any liquid , just the top of the radiator parts in there. There is a tube going into the reservoir tank at the top, and a tube coming out at the bottom at the back. The system is self regulating (I assume), because it will reclaim coolant from the tank if there is enough coolant in the reservoir tank. I think that if the reservoir is between MIN and MAX, you are OK, because it says to add coolant to the reservoir, not the radiator, if there is any liquid at all in the reservoir.

Anyone else have a take on this?

Normally the cooling radiator sucks coolant back out of the overflow tank. That is, if it can get suction.

Check the line going from the top of the radiator to the overflow tank. Is it connected, leaking, damaged? Anything odd?

If you don't see anything obvious talk to your dealer. You wouldn't want to overheat or suddenly loose coolant.

Be sure that the line from the cap to the overflow tank is not collapsing under vaccum or pinched somewhere, and have the radiator cap pressure tested. Most any shop will have a cap tester. Don't forget..DO NOT OPEN HOT, it is a closed system and will spray hot coolent if opened hot.

Confirmed. I watched my level before and after starting the engine. The coolant is almost all sucked back into the engine. See if your's does the same. I don't think you have a problem, but it can't hurt to have it checked out either.

Well I looked at it again, this time the overflow tank was just a little high, but when I opened the radiator (engine was cold) antifreeze came out, it was over filled slightly. So, I got the overflow tank to it's proper level by sucking some out, and when I went back to the radiator it was very low again! I couldn't see any fluid. So I filled it up slowly, only to notice that as I filled the radiator up, the overflow tank was over filling! I have no idea what's going on here as the overflow tank tube is connected at a very high point at the cap, and I was carefully to poor fluid into the radiator, and not into the overflow tube pick up... I'm calling the dealing now, lol!

Yeah just let them check it out. Maybe the system needs to be bled a bit.

I called the service center and they are booked until next week, but the service manager (who probably doesn't know a torque wrench from a muffler bearing) said that he didn't think it was a problem but would take a look next Tuesday if I wanted. Currently after one more warm up cycle the tank if 3" over the max line and I haven't opened up the radiator because I just don't think I even want to know at this point! lol. Thanks for all the feedback.

A collapsed/partially plugged hose between the radiator and the tank or a plugged vent hole in the recover tank could cause this.

Radiator cap has (2) parts - big spring maintains pressure and allows and excess/overpressure to flow out into recovery tank. little brass cap prevents it from flowing out but should let it flow back in - It could be stuck as well.