bluebug 27 #1 Posted September 23, 2015 (edited) My 523Dxi was running real warm. The indicator was all the way to the top of the green bar.I tested it with a digital thermometer and it was reading 194 at the thermostat housing. Which is not much more than one would expect at that location.I ordered and replaced the thermostat and the temperature sending unit. Thermostat was stuck open.It is running some cooler now but I have not run it longer than 20 minutes and have not cut grass with it yet. I will recheck when next I cut and post some more pictures. Edited September 23, 2015 by bluebug 1 Share this post Link to post Share on other sites
WNYPCRepair 1,923 #2 Posted September 23, 2015 Wouldn't the thermostat stuck open make it run cooler? 1 Share this post Link to post Share on other sites
bluebug 27 #3 Posted September 23, 2015 Would make it take longer to warm up, but not run cooler once warm. 3 Share this post Link to post Share on other sites
shallowwatersailor 3,214 #4 Posted September 23, 2015 I went back and looked at your original photos. I didn't catch it then but the overflow tank looks like it overflowed. Hopefully the head gasket didn't go. Have you cleaned the screen and fins on the radiator? Make sure the fan is drawing air through the radiator, not pushing it. The other thing to check would be the water pump. Leave the cap off and run it until you see flow in the radiator as it warms. If you haven't changed the antifreeze, it needs to be "burped" to get rid of air pockets by raising the rear wheels up ramps or incline due to the engine-radiator arrangement. 1 Share this post Link to post Share on other sites
bluebug 27 #5 Posted September 23, 2015 The overflow tank has overflowed.I did a combustion chamber leak down test and it did not show any head gasket issues.Screen is clean and air is flowing forward through the radiator.I change the anti-freeze with the thermostat and ran it until thermostat opened and it had good flow to get any air out.I will know better once I run it to cut grass next week, and get it warmed up good.Clark 1 Share this post Link to post Share on other sites
shallowwatersailor 3,214 #6 Posted September 23, 2015 Just to clarify, the airflow should be towards the front of the tractor exiting through the grill. It draws from the screens by your feet. Also, hopefully the old thermostat was intact when you removed it. Share this post Link to post Share on other sites
bluebug 27 #7 Posted September 23, 2015 Yes, air flow is from the radiator forward to the front of the tractor.The thermostat was stuck but entirely in one piece.Clark Share this post Link to post Share on other sites
shallowwatersailor 3,214 #8 Posted September 23, 2015 Okay, lets hope that it was just the thermostat. Keep us posted. 1 Share this post Link to post Share on other sites
bluebug 27 #9 Posted December 3, 2016 Took the radiator out this week, and found at least half of the cooling fins clogged with mud. Soaked it and sprayed it several times for two days and finally got all the mud out. Should help eliminate this problem. Clark Share this post Link to post Share on other sites
shallowwatersailor 3,214 #10 Posted December 3, 2016 1 hour ago, bluebug said: Took the radiator out this week, and found at least half of the cooling fins clogged with mud. Soaked it and sprayed it several times for two days and finally got all the mud out. Should help eliminate this problem. Clark Thanks for the followup. Please post again after using it with the cleaned exterior. Also, remember to burp the radiator to remove the air pocket., Share this post Link to post Share on other sites
