I was just checking fluid levels on my STI 2 last night and noticed that the plastic overflow tank on the right side of the engine as you look from the front was empty and also there was a brown mucky substance on the inside wall of the plastic overflow tube.
Are either of these something to worry about? Is this suppose to be full and what is that mucky substance?

I then checked the header tank over on the other side of the engine and this was full to the top(looked like more coolant than water) but full all the same.

Any suggestions lads..

Cheers.

 

Anyone?

 

Im still here..

 

Reservoir should be full to the brim. Overflow full to the full mark.

 

Does that mean that the car is either using or loosing collant somewhere. I thought the purpose of an overflow was to take the water/coolant so why would you want it to the full mark?

 

Does that mean that the car is either using or loosing coolant somewhere. I thought the purpose of an overflow was to take the water/coolant as the temp would rise so why would you want it to the full mark?

 

Your coolant should be about the low level indicator when cool and at the full mark at operating temperature.

The brown cr@p in the coolant sounds like bad news. There should not be anything but a nice green/blue liquid in your coolant if there is gundge in it then it could be a blown gasket or worse

 

It caught me out also. I found mine overheating mildly after i neglected (didn't know) to top up the 'expansion tank'. I initially found the setup a little bizarre compared to what i was used to/expected.

My understanding is that the system is designed to run under pressure. By doing this is keeps the water temperature down to a manageable level. If you give the coolant room to expand it will warm further until it reaches normal operating pressure - hence the mild overheating i had.

Top it up and see how you get on.

 

Thanks lads for your replies. I was speaking to a very trusted member of SN today about this and he assured me that it was not necessary to have coolant in the expansion tank as it will use this tank when required(when temperature rises) and then go back when at normal temp.
He also said that the brown stuff was normal and nothing to worry about. I did top it up tonight and took the car for a spin, when I cam back I had a look to see if there was any bubbles or anything in the expansion tank but thankfully there wasnt.
Having said that, the level didnt seem to have moved at all. Ok I didnt trash the car but took it for a 5 mile drive..
Carl, when you say your car was overheating mildly, in what way did you notice this. I thought this would ahve been visable from a rise in level on the expansion tank??

 

bttt