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I have a 1992 37Y Southwind that I think is running too hot. It has a 454 Cheverolet engine with 11,000 miles (good wrench replacement), and 4l80 automatic transmission (cheverolet rebuilt with 3,000 miles). At this time there is not an auxilary transmisson cooler, but I plan on adding one. I have had the motorhome for 9 months and have put all of the 11,000 miles on the engine. The temperature gauge has marks @ 210 degrees, and 260 degrees, with unlabled mark in the middle between the two ( I assume 235 degrees. On flat level road in 90 degree outside temperature the temperature of the engine will be right around the 210 degree mark. But on any hills the temperature will rapidly rise and can reach close to 235 degrees!!! on mountain grades. Coasting on a downhill grade the temperature will move slightly below the 210 degree mark. The thermostat is 195 degree and was replaced recently. The electric fan infront of the radiator was replaced due to a bad bearing and is working. The exterior of the radiator is free of debris. There is a 50/50 mix of antifreeze and water in the radiator. The fan shroud is in place. The water pump belt is properly tensioned. I suspect the problem may be the thermostatic clutch on the engine fan. The clutch engages when the engine is first started cold and then disengages after a minute or so as I am told it should. However, underload, going up a hill with engine rpms above 2000 rpm the fan does not engage ( as noted by the increased sound of the engine fan) eventhough the engine temperature is indicating around 235 degrees. I have found that if I take my foot off of the accerator pedal and let the engine rpm drop somewhere below 2000 rpm the clutch will engage I can then press the accelerator pedal to continue up the hill, and the engine temperature will fall or at least not continue to rise. On shallow grades the temperature can fall rather rapidly. Is this a failure mode of a thermostatic clutch where it will engage at low rpms when the temperature reaches the engagement point, but will not engage when the engine rpm is high when it reaches the engagement temperature? My mechanic says there is nothing wrong with the clutch based on the cold start actions. I think differently. If the clutch is bad, should I replace it with a cheverolet replacement clutch, or is there an aftermarket clutch which would be better suited for use in a motorhome? I know this has been rather long, thanks for any advice. This is my first motorhome and I love the rv lifestyle.
I have a 1992 37Y Southwind that I think is running too hot. It has a 454 Cheverolet engine with 11,000 miles (good wrench replacement), and 4l80 automatic transmission (cheverolet rebuilt with 3,000 miles). At this time there is not an auxilary transmisson cooler, but I plan on adding one. I have had the motorhome for 9 months and have put all of the 11,000 miles on the engine. The temperature gauge has marks @ 210 degrees, and 260 degrees, with unlabled mark in the middle between the two ( I assume 235 degrees. On flat level road in 90 degree outside temperature the temperature of the engine will be right around the 210 degree mark. But on any hills the temperature will rapidly rise and can reach close to 235 degrees!!! on mountain grades. Coasting on a downhill grade the temperature will move slightly below the 210 degree mark. The thermostat is 195 degree and was replaced recently. The electric fan infront of the radiator was replaced due to a bad bearing and is working. The exterior of the radiator is free of debris. There is a 50/50 mix of antifreeze and water in the radiator. The fan shroud is in place. The water pump belt is properly tensioned. I suspect the problem may be the thermostatic clutch on the engine fan. The clutch engages when the engine is first started cold and then disengages after a minute or so as I am told it should. However, underload, going up a hill with engine rpms above 2000 rpm the fan does not engage ( as noted by the increased sound of the engine fan) eventhough the engine temperature is indicating around 235 degrees. I have found that if I take my foot off of the accerator pedal and let the engine rpm drop somewhere below 2000 rpm the clutch will engage I can then press the accelerator pedal to continue up the hill, and the engine temperature will fall or at least not continue to rise. On shallow grades the temperature can fall rather rapidly. Is this a failure mode of a thermostatic clutch where it will engage at low rpms when the temperature reaches the engagement point, but will not engage when the engine rpm is high when it reaches the engagement temperature? My mechanic says there is nothing wrong with the clutch based on the cold start actions. I think differently. If the clutch is bad, should I replace it with a cheverolet replacement clutch, or is there an aftermarket clutch which would be better suited for use in a motorhome? I know this has been rather long, thanks for any advice. This is my first motorhome and I love the rv lifestyle.
As an retired "auto tech", I'll start with "don't always trust the gauge", or as we used to put it, "test your tester". I agree with the mech, the fan clutch sounds as if it's working OK. If your engine doesn't seem to be running as hot as indicated, (no hot rubber or other overheated smells), then I'd say your engine isn't getting hot enough to have the air passing through the radiator activate the thermo-spring on the front of the fan clutch. Is the electric fan coming on? If you want to test the fan clutch, the block 1/2 of the front of the radiator with cardboard, leave the area in front of the fan clutch open, start the engine, let it warm up, then block the throttle open to get around 2,000 RPM and listen/watch for the fan to "kick" in as the engine temp rises. The clutch is supposed to come in around 205-210 degrees. To check the gauge, start with a cool motor, remove the radiator cap and insert a candy thermometer into the opening. Start the engine and warch the thermometer and the coolant. In as much as you have a 195 degree thermometer, ( 180 would be better), you should see coolant flow start around 185 + degrees, see what your dash gauge says now. Electric gauges can be as high as 10%-15% off.
I have a 1992 37Y Southwind that I think is running too hot. It has a 454 Cheverolet engine with 11,000 miles (good wrench replacement), and 4l80 automatic transmission (cheverolet rebuilt with 3,000 miles). At this time there is not an auxilary transmisson cooler, but I plan on adding one. I have had the motorhome for 9 months and have put all of the 11,000 miles on the engine. The temperature gauge has marks @ 210 degrees, and 260 degrees, with unlabled mark in the middle between the two ( I assume 235 degrees. On flat level road in 90 degree outside temperature the temperature of the engine will be right around the 210 degree mark. But on any hills the temperature will rapidly rise and can reach close to 235 degrees!!! on mountain grades. Coasting on a downhill grade the temperature will move slightly below the 210 degree mark. The thermostat is 195 degree and was replaced recently. The electric fan infront of the radiator was replaced due to a bad bearing and is working. The exterior of the radiator is free of debris. There is a 50/50 mix of antifreeze and water in the radiator. The fan shroud is in place. The water pump belt is properly tensioned. I suspect the problem may be the thermostatic clutch on the engine fan. The clutch engages when the engine is first started cold and then disengages after a minute or so as I am told it should. However, underload, going up a hill with engine rpms above 2000 rpm the fan does not engage ( as noted by the increased sound of the engine fan) eventhough the engine temperature is indicating around 235 degrees. I have found that if I take my foot off of the accerator pedal and let the engine rpm drop somewhere below 2000 rpm the clutch will engage I can then press the accelerator pedal to continue up the hill, and the engine temperature will fall or at least not continue to rise. On shallow grades the temperature can fall rather rapidly. Is this a failure mode of a thermostatic clutch where it will engage at low rpms when the temperature reaches the engagement point, but will not engage when the engine rpm is high when it reaches the engagement temperature? My mechanic says there is nothing wrong with the clutch based on the cold start actions. I think differently. If the clutch is bad, should I replace it with a cheverolet replacement clutch, or is there an aftermarket clutch which would be better suited for use in a motorhome? I know this has been rather long, thanks for any advice. This is my first motorhome and I love the rv lifestyle.
As an retired "auto tech", I'll start with "don't always trust the gauge", or as we used to put it, "test your tester". I agree with the mech, the fan clutch sounds as if it's working OK. If your engine doesn't seem to be running as hot as indicated, (no hot rubber or other overheated smells), then I'd say your engine isn't getting hot enough to have the air passing through the radiator activate the thermo-spring on the front of the fan clutch. Is the electric fan coming on? If you want to test the fan clutch, the block 1/2 of the front of the radiator with cardboard, leave the area in front of the fan clutch open, start the engine, let it warm up, then block the throttle open to get around 2,000 RPM and listen/watch for the fan to "kick" in as the engine temp rises. The clutch is supposed to come in around 205-210 degrees. To check the gauge, start with a cool motor, remove the radiator cap and insert a candy thermometer into the opening. Start the engine and warch the thermometer and the coolant. In as much as you have a 195 degree thermometer, ( 180 would be better), you should see coolant flow start around 185 + degrees, see what your dash gauge says now. Electric gauges can be as high as 10%-15% off.
Greg, Get your self a good after market temp gauge. As the retired auto tech said the factory gauge can be decieveing and unreliable. I was also running a tempature with my rig and found out the radiator was plugged. I recored the radiator among other things and dropped my temp 30 degrees. If you want to know details you can E-mail me. viscomann@aol.com
email Greg Holbrook
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