[QB93Z]

I like your approach, Cliff

On a few occasions, I had cooling problems in my high mileage, 1994 Yellow ZR-1 with the original radiator. The problems occurred when I was stuck in stop and go traffic on a hot day. These conditions match the test condition Cliff is describing.

In March 2014, in preparation for our 30-day trip to the Southwest, I tried to clean the radiator of debris by blowing compressed air through from the back (fan side). I decided that the cleaning method was not working very well so I chose to remove the radiator from the car so I could clean it more completely and straighten some fins that I bent trying to use the compressed air.

With the radiator out of the car it was obvious that there was debris stuck in the fins. The best way I found to remove it was to lay the radiator flat on the driveway, lift it about 3 inches and slam it down on the concrete. Each time I did this, I got a debris pattern of fine, grit like fine sand, that matched the circles of the two fans. I repeated the mechanical shock cleaning many times until the grit was mostly gone. I straightened the fins and reinstalled the radiator.

With the cleaned, original, 150,000 mile radiator, the cooling system, is working fine. I had no problems in the Southwest or on any trip since.

I believe that any cooling system analysis needs to address the air flow through the radiator. Based on the conditions of my radiator, I doubt that even an additional fan or higher flow fans would have helped.

Thinking back, based on the time it took to clean the radiator, it might have been better to just install a replacement radiator. At the time, I was interested in seeing if I could "solve the problem". On other ZR-1's, I have installed both the DeWitts and the Ron Davis radiators.

Jim