I have no idea how many times I'm going to have to beat this into the ground, but here's 3,467,201...
There is nothing intrinsically wrong with the RENIX "closed" cooling system. If the "closed" system idea is inherently worse, why is it picking up speed with OEM applications?
Considering I've got four RENIX rigs, and only one converted (and I'm honestly thinking of converting it back to closed system!) I can honestly say that all you need to do is maintain the thing as well as you normally would, make sure the system is flushed and coolant changed every alternate year, and keep an eye on the pressure bottle (keeping a spare around woudn't hurt - go to
www.morris4x4center.com to order one - with cap - for about $22.)
The only real "issue" with the RENIX system is the radiator. From experience (and from talking to Jeep techs) the usual service life of the RENIX OEMR radiator is 120-170Kmiles, whether it came with the vehicle from the factory or you get it from Jeep. Replace the radiator with a Modine or a Performance Radiator replacement unit, and forget about it (I've got a Modine in daily service with 80K or so on it, and a Performance Radiator unit in service with at least 130K on it. Neither show any sign of trouble.)
Some of us "old hats" batted this one around for a while, and we decided it's an answer in search of a question. The whole craze probably started when someone was getting overheats (due to a failed radiator - see comments above) and just did the conversion while he was about it. Since it was a new radiator going in, he fixed the problem - there was just a lot of unnecessary work involved. Replacing the radiator witha quality aftermarket unit would have served.
Considering I've pulled the RENIX closed cooling system down to an operating temperature of 190-195 degrees Fahrenheit with only minor modifications, there really is nothing wrong with it - and converting it is an answer in search of a question, as I'd mentioned. My "closed" rigs run cooler than the one that was converted to "open!" Go figure.
Search for my other posts on the subject to attain enlightenment - I've covered this myriad times in the last several years, and I'm sure there are still a few posts somewhere around here. I've also worked up the FAQ article (currently in review - Mark?) that should get posted when it comes to pass that we get a FAQ section together...
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