I have a 2013 jku rubicon. 37's, 4:88, flash cal, CAI, resignator removed and muffler relocate, winch, bumper. I could go on for days to list mods 38k miles. Live in denver metro
2 months ago I noticed it was getting warm ( 2/3 mark on temp guage still in white) pull over to find I am leaking antifreeze somewhere, added some antifreeze and fill it up. Drove for a few days filling up antifreeze as necessary. The radiator cap never got hot and the radiator never lost fluid only the resivor, however when opening the radiator cap it made a suction sound and the resivor would fill with bubbling fluid. Didn't think head or gasket because No mixing of raidiator fluid and oil, in either one, no smells to speak of, heat and ac work fine, performance is normal, no smoke. Made an appointment had a custom high efficency copper/brass radiator built and installed, also found out leak was thermostat housing. Had that replaced, new thermostat, new water pump, new backer plate, new impeller. $1,500 Picked it up drove 5 miles at 60 mph and it climbed up to 2/3 almost instantly. Test drive with the guy he plugged in his computer and it was 244 degrees. Went back they went through the burp process couldn't find any issues. Few days later I drive it from one shop to the other, 5 miles to jeep. Where it currently lives going into week 4. (Total of 7 weeks now now vehicle between 2 shops) They have "diagnosed" it to find nothing wrong. I explained to them how to simulate the heat issues going over 65 on an incline etc. Or be in drive with foot on brake at 1500 rpm to simulate a climb or putting it under load, they do neither. They are insisting to me that there is nothing wrong etc. Of course blaming it on my mods if anything is wrong. I am saying every mod on this jeep has been there for 3 yrs I have always had the temp guage on the center unless i am towing a trailer up in mountains then it would hit 2/3 even then is rare. I drive my jeep like its stolen daily for 3.5 yrs, never heats up. Now with a super high efficency radiator driving on flat ground at 60 2/3 temp is normal?
Clearly by reading this I'm not much of a mechanic, however I just feel like I'm getting pushed out the door at jeep with zero resolution and this is going to lead to head, head gasket, or block failure. Based on the quote from the service manager that 280 degrees is with in normal operating range for these motors. Also i did ask the service manager and GM ar dealer to do a compression test of each cylinder and i am awaiting results of that. Any suggestions?