Gunk in my 1 yr old copper rad

[Nathan]

Last year I put a new copper radiator in from performanceradiator.com. Yesterday I opened the rad cap to look and theres brown gunk coating the fins.

Is this normal or should I get it flushed?

What could cause this after 1 year? Not enough coolant?

BTW I used Prestone's green coolant with carbon-filtered water. The coolant came out looking clean. Car runs fine at 180-185F.

Nathan

 

[Kestas]

It may be manufacturing oils that weren't properly flushed from the radiator. Give it a detergent flush and keep an eye on it for any further buildup that may indicate other problems.

 

[doitmyself]

Hey, I'm getting lots of "mileage" out of posting these two excellent reference articles:

http://www.gates.com/brochure.cfm?brochure=2822&location_id=2877

http://www.aa1car.com/library/2005/us90554.htm

If your coolant is the newer all makes, extended life Prestone product, it is an OAT coolant. The articles above recommend not using this type with copper/brass radiators. Maybe you had cooolant "clash" if you didn't remove the old stuff completely? Just guesses on my part.