Orange Sludge In Coolant Resevoir

[Kurt C. Hack]

I recently performed the 30k maintenance on my 2002 OB 2.5l. Part of
this service was the drain and refill of the radiator and coolant
recovery bottle. The coolant drained from the radiator was nice and
clean, but I noticed when I drained the recovery bottle that there was
some orange sludge and a few chunks that settled at the bottom of the
bottle. I removed it and cleaned it out real well, but I'm curious if
anyone else noticed this. My main concern is that this is "normal"
behaviour and not something I need to alert my dealer of.

Thanks!

-Kurt

 

[George]

I recently performed the 30k maintenance on my 2002 OB 2.5l. Part of
this service was the drain and refill of the radiator and coolant
recovery bottle. The coolant drained from the radiator was nice and
clean, but I noticed when I drained the recovery bottle that there was
some orange sludge and a few chunks that settled at the bottom of the
bottle. I removed it and cleaned it out real well, but I'm curious if
anyone else noticed this. My main concern is that this is "normal"
behaviour and not something I need to alert my dealer of.

Thanks!

-Kurt

Older 2.5 L engines (e.g. my '97) had *big* problems with head
gaskets blowing and/or cracks in the block. These caused
air bubbles in the coolant and consequently overheating on long
trips. I don't think the 2002 has that problem -- but you never know.

To reply directly to me, replace all 'z' with 'a' in email address.

 

[Edward Hayes]

I think it fairly common as the overflow bottle is open to atmosphere and
ever time the radiator cools off the coolant contracts in the radiator and
draws coolant from the recovery bottle. When coolant is drawn from the
recovery bottle air from outside replaces the volume of liquid. Dirt in the
air is also drawn into the bottle and causes the sludge and discoloration. I
have seen it on almost every car I've changed coolant on. ed

 

[Marc Soloway]

Be aware, there is a technical service bulletin/ recall on most of the 2.5
SOHC engines, to put a coolant conditioner in with every time you change the
coolant, as well as in the car today.

Make sure to run the car for a minimum of 30 minutes with the conditioner
with the heat on.

Marc Soloway
Natick Subaru Sales