Coolant above max level: What adverse effects can this cause?

[T3KT0N1K]

I've noticed that my temperature gauge takes, what I believe is an abnormally long time to reach 90. I know what a failed/failing thermostat is like on a 1.8T AUM engine, as suffered one on my old Mk4 Golf GTi and subsequently replaced the stat myself.

Anyways, after performing a quick visual check of the associated bits n bobs, I've noticed my coolant fluid is above the max fill level. Can this be causing the issue? I know the fluid is hazardous and that the system is pressurised (or at least it should be), so I'm guessing elevated pressure, resulting in cracking or leaks throughout the system could occur, right?

How should I go about lowering the level? Syphon it out somehow?

 

[LEE69]

Noticed my diesel is slow to warm to 90 was warned before i bought it compared to my AUQ Leon.
Level shouldn't rise, where would the extra come from?

Syringe to suck some out or a clean rag to soak it up?

 

[T3KT0N1K]

Syringe to suck some out or a clean rag to soak it up?

Not a bad idea.

The only way there could be excess is if someone overfilled the reservoir. That must've happened while the car was in the hands of it's previous owner. I've only had it a couple of months and probably should've spotted it earlier.

 

[MrLapou]

Of course the level should be checked when the coolant is cold.

 

[T3KT0N1K]

Of course the level should be checked when the coolant is cold.

Understood. I am well versed in the book of Haynes, having performed a thermostat replacement in the past.

 

[fangio]

If it doesn't blow coolant out anywhere, forget it!

 

[Bailer]

Shouldn't make a difference, Can't see anything popping cracking or leaking. There's lots of room in the expansion "ball". It would want to get really really hot. and with additional coolant that might take a fraction longer.

A lot of Garages/mechanics will fill that just over the max line just to allow for settlement after you've run it for a while.

 

[MouseGB]

Agreed, drain off the excess and check the strength of the antifreeze, keep an eye on it. Just one note, you can compress air but not fluid but even if it over pressurised the valve would open. What would worry me is if there is emulsified oil in the water.