Coolant Turning Greenish Brown

[Sidshk]

Hi 

While changing Engine Timing belt mechanic found my coolant has turned into sort of greenish brown color, Any guesses the reason for it ? should i be worried ?

 

Note 

I have changed my radiator recently and topped it with Mitsubishi original coolant 

 

 

[Gaurav]

If coolant has turned greenish brownish inside the expansion bottle, then its fine. Clean the coolant bottle and refill. I am facing same in my ancient Pajero.

If coolant inside the radiator turned brownish, then it's a concern. Please confirm.

[shadow79]

remove the thermostate then flush the system and then put a new thermostate and fill it again with toyota pink coolant bleed the system and have fun... 

Edited September 11, 2019 by shadow79
more info

[Sidshk]

3 hours ago, Gaurav said:

If coolant has turned greenish brownish inside the expansion bottle, then its fine. Clean the coolant bottle and refill. I am facing same in my ancient Pajero.

If coolant inside the radiator turned brownish, then it's a concern. Please confirm.

Its from inside the Radiator 

3 hours ago, shadow79 said:

remove the thermostate then flush the system and then put a new thermostate and fill it again with toyota pink coolant bleed the system and have fun... 

Recently changed thermostat and Radiator  , its only 3 months old 

[shadow79]

Still better to toss a thermostat and it's seal then feel sorry and waste the money on flush and coolant

[Sidshk]

2 minutes ago, shadow79 said:

Still better to toss a thermostat and it's seal then feel sorry and waste the money on flush and coolant

K will try it 

[Gaurav]

If previously bleeding is not done by removing thermostat then saleem might be right, as engine jacket hold lot of coolant and the new and old coolant must have got mixed.

If you have bleed it before, then double check if its brownish or whitish? Has any sticky feel? Pungent smell?

[Sidshk]

10 hours ago, Gaurav said:

If previously bleeding is not done by removing thermostat then saleem might be right, as engine jacket hold lot of coolant and the new and old coolant must have got mixed.

If you have bleed it before, then double check if its brownish or whitish? Has any sticky feel? Pungent smell?

No Its not sticky and doesn't have  Pungent smell , its just changed color 

Brownish like Mountain Dew color  

[Gaurav]

Have you bleed the cooling system previously?

[Sidshk]

1 hour ago, Gaurav said:

Have you bleed the cooling system previously?

Yes , it was done during change of cooling system