HELP - orange foam from radiator overflow? - SOLVED!

03forester-noob said:

after a long 1200 mile road trip my car started spewing an orange foam from the radiator overflow i ended up stopping at a sketchy auto body shop in the middle of nowhere to drain my radiator, they really didn't do a good job flushing it but i had no tools on hand to do it myself. i ended up having the same issue about 800 miles later when the overflow turned from green to orange. I'm worried it could be oil in the radiator, i want to try and flush it with chemicals and use some repair fluid but not sure. but not sure any advice would be appreciated

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"...spewing an orange foam from the radiator overflow ....."

The only coolant that is colored "orange" is DexCool. This is the GM-spec, long drain interval coolant ...and it's actually "salmon-colored".

DexCool is not compatible with normal anti-freeze ...apparently the "green" stuff that came blowing out of your rad after your visit to the "sketchy" auto body shop must've been normal ethylene glycol coolant ...usually the stuff is blue or yellow but if there was some DexCool still in the system I guess you could mix blue and "orange" and come up with green.

Do yourself a favor and go down to the nearest well-regarded independent shop and have them do a complete drain and flush of your cooling system. Tell them you may have long drain interval coolant (DexCool) mixed with standard coolant. You didn't give us any info on the model year of your car but I'm assuming it's probably an older Forester. When the shop fully cleans out your cooling system you need to decide what type of coolant to install. Opting for long interval drain coolant is a good idea. Most shops will carry DexCool and that would be what I would use. I have it in my '98 GMC pickup and it keeps the cooling system clean and working great ...providing you check the coolant level regularly and you service it with DexCool spec coolant.

If you're gonna do this yourself then get at least two or three bottles of heavy duty cooling system flush. First drain the coolant from the car and flush it until the water runs clear. Don't forget to flush the heater core. Button everything up, add all the bottles of flush then fill the system with water. Drive the car for a few days with the water/flush mix then drain and flush the system again. Refill the system with a 50/50 mix of whatever type of coolant you want. Just be aware long drain interval coolants are *NOT* compatible with standard anti-freeze; DO NOT MIX THE TWO.

If you have a shop do the flush ask to have a cooling system check performed. This is a simple test where a hand pump is used to pressurize the cooling system. Prior to pressurizing the system a florescent dye is mixed in the coolant. If the system fails to hold pressure then there is a leak somewhere and they will trouble shoot the system to find where the coolant is leaking; the dye is a telltale when viewed under black light.

If there is a leak or, worse, if a cylinder head gasket has blown then the repair will run from "can be expensive" to "will be expensive". For a blown head gasket the solution is a gasket replacement; those "pour-in-the-radiator" head gasket "fixes" are nothing but trouble. The action of the repair fluid can screw up your radiator and not even fix the leaking head gasket ...or at least not for very long.