Finish Cleaning the Radiator
reprinted from the Milepost
Nov/Dec 1996 - Kansas City BMW Club
by Ray Spitzer
The September Roundel had an article on E36 maintenance. I would like to add some additional, important steps concerning flushing the radiator. Every time I flush the cooling system I also remove the radiator. Although this requires removing the upper and lower radiator hoses, the coolant recovery line, and a few clips, it's not as hard as it first appears. At first, I was skeptical if this was necessary, but as I passed the garden hose across the exterior fins of the radiator (in the reverse direction of air flow) I couldn't believe the amount of crud that came out. As you know, the fins on the radiator are heat sinks that aid in dissipating heat as we drive our Bimmers, these fins accumulate a tremendous amount of road debris, bugs, leaves, etc. If neglected, it would begin to restrict the air flow, requiring your cooling system to work harder to maintain a nominal engine temperature. If you do it yourself or have your favorite shop do a coolant system flush, insist that the exterior of the radiator be flushed clean of debris.