Black residue in coolant tank?? Additive?

[SVX_commuter]

I am looking at a 95 Legacy 2.2L and the coolant expansion tank has a very dark residue on the inside of the tank, all over the tank, can't see any plastic thru it. There appears to be a coating of something black in color all over the inside of the tank. The coolant also looks very dark not green. It has oh about 196k miles on it. If I can find out about this coolant thing it might be okay to buy.

Is it some kind of additive?

 

I would appreciate hearing from anybody with experience on this.

 

 

Thanks

[Brumby Boy]

Dont quote me or anything but i think it is just a type of alge/slime. dont know if it is bad or not.

[tomson1355]

If it was a 2.5L, I'd say leaky head gasket. I'd still want to rule that out if I were you, along with a cracked block or head. Check to see if there is coolant in the reservoir but not in the radiator. Check to see if there are bubbles coming up through the coolant when the engine is running, and check whether the coolant expands into the reservoir and stays there after the engine cools. Hopefully it is just Stop Leak, and it hasn't plugged up the system anywhere.

 

Tom

[Setright]

Start by draing the coolant, flushing with pure water, and refilling with fresh coolant. Run for a while and check again.

 

I would of course recommend reading my essay on doing this the right way :-)

 

Search the forum for "coolant replacement" and the choose the "without bubbles"

[NorthWet]

I am looking at a 95 Legacy 2.2L...

Probably doesn't have the ability to do coolant work on this car yet...

 

Gunk seems to accrete in the expansion tank. I would imagine that what setright is talking about would take care of things. Do you know if the heater puts out heat? The heater core is usually the first thing to plug if there is debris/gunk in the coolant.