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James, I have two questions, and the first is For my 1993 5.7 liter TBI engine, I just replaced the radiator, water pump with belts and new hoses. I also replaced the thermostat. I believe the thermostat rated for this vehicle is a 195 degree And I put in a 180 degree. The engine still seems to be heating up more than I would like. Would I be hurting anything by going to a 160 degree thermostat on that vehicle? Secondly, The A/C is not working and I believe the compressor seals have popped. I don’t really Want to go to the new R134 system since I will have to replace the entire system which will be very expensive. Do you think there would be any chance of anyone being able to help me get my existing system going? Thanks for any ideas you have, Scott B.

Scott, Automotive engineers who get paid to “tear up” engines in the laboratory tell me they can destroy an engine quicker by running it at 160 degrees. This is due to the engine not getting hot enough to evaporate the acids in the crankcase. Your trucks engine requires 195 degree thermostat, nothing cooler! Your trucks electronics are calibrated for the engine to run at this temperature. Besides effecting fuel mileage you are promoting premature transmission failure. Running a too cool thermostat will contribute to “crankcase sludge” in your engine. This will cause your trucks engine to smoke and use oil prematurely. This is why older cars engines of the 1960’s and 70's wore out and smoked by the time they had 100,000 miles. Running the engines too cool with inferior oil by today’s standards. So if you think you have an overheating problem you need to make sure that it is not a head gasket problem. To verify the truck can cool down when it is hot, just take a water hose to the radiator while the truck is running. If the temperature gauge goes down then you have a problem with the fan or radiator. If it still gets hotter and won’t cool down then you have a head gasket (or cracked head) or the wrong water pump (turning backwards) As to the A/C system keeping R-12 as the refrigerant is the smart thing to do in the long run. R-12 may cost more than R-134a. In the long run it will do a better job keeping you cool and you’re a/c system lasting longer. James C. Morris


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