SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 What happens when you turn the aux fan on? Does it bring your temps down and keep them down? Or does it continue to overheat? Continues. I can have it on from a cold start to almost red. Doesn't make much difference. Only thing seems to move the needle down is those higher rpms pushing the pump. It almost feels like the radiator isn't cooling but it's been the same with all 3 radiators. Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 Have you pinched your upper radiator hose on a cold engine right after warm up with your bare hand to feel coolant flow, the temp of coolant, while at same time listening for a slight idle down? So pinching the upper hose should drop the idle? Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 I know on my closed systems, I can tell immediately coolant flow with the thermostat open at operating temp with a quick pinch of the upper hose with my bare hand. You will feel how hot the coolant is through hose(gives you a check against true coolant temp if its flowing unrestricted vs. an air pocket temp which would throw things off. If its not flowing good you will not feel pressure in the upper hose with your bare hand. You should feel the surge as you release it. You should also hear slight changes in the engine idle when you perform this. A renix can easily give false temps through air pockets when locked and no coolant flow. Then there is a sudden spike and boil over at overflow cap. Yours is open cooling since its a 92. H.o.s still need some help with being burped or purged of air with a coolant system service. Have you rrally done that. My 2000 xj was as stubborn as my 88 renix. I think it may have to do with poor maintenance from p.o. and heavy scaling. In 5 years of ownership, I went through 2 autozone radiators, 3 water pumps, and had to flush that puppy every time that pump was changed. There was heavy scaling every time which I believe caused the water pump failures. My mjs ran all the same components cheaply made from autozone and never a problem. The xj had seen 40,000 more miles though in a shorter lifespan(rest in peace xj). I also think I had a bad head gasket toward the end when pump and radiator were replaced twice within a year and half. The radiator looked near brand new. Pulled the lower hose to bleed the system fast and it looked like red clay. I'm about 12 beers and half a bottle of Irish whiskey in but I'll read and respond tomorrow morning lol. Thanks guys for chiming in. I love this truck but the hit on the paycheck is making it difficult to justify when it's on stands more than the road. Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 Hahaha inlaws and wife drug me out to middle of nowhere Oklahoma or I'd be out there drunk or not lol. I got em back by running around in my American flag silkies (Ranger panties) all day.Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
omega_rugal Posted May 27, 2018 Share Posted May 27, 2018 somethign is blocking the flow of the coolant... i mean before you start throwing random stuff at it make sure coolant is even moving.... Link to comment Share on other sites More sharing options...
SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 somethign is blocking the flow of the coolant... i mean before you start throwing random stuff at it make sure coolant is even moving.... Like I said coolant is flowing. Temps wouldn't be dropping at all. Each of the radiators were flow tested before installing. Water jackets were the first thing that came to mind so the head was pulled. While it was out it was slightly out of tolerance so I picked up a new one. Each thermostat was tested using an IR thermometer and the only one that was off enough to notice was the Mopar one. Bottom line was reinforced with a spring. New hoses all around and the heater core was backflushed. Coolant over flow was replaced just due to how much crap was in it since it was original. Haven't been throwing random parts aside from the csf radiator, clutches for the fans and thermostats. Great input though. I've been dealing with this issue for over a year non stop and it's not my first jeep. Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
SBpunk Posted May 27, 2018 Author Share Posted May 27, 2018 I know on my closed systems, I can tell immediately coolant flow with the thermostat open at operating temp with a quick pinch of the upper hose with my bare hand. You will feel how hot the coolant is through hose(gives you a check against true coolant temp if its flowing unrestricted vs. an air pocket temp which would throw things off. If its not flowing good you will not feel pressure in the upper hose with your bare hand. You should feel the surge as you release it. You should also hear slight changes in the engine idle when you perform this. A renix can easily give false temps through air pockets when locked and no coolant flow. Then there is a sudden spike and boil over at overflow cap. Yours is open cooling since its a 92. H.o.s still need some help with being burped or purged of air with a coolant system service. Have you rrally done that. My 2000 xj was as stubborn as my 88 renix. I think it may have to do with poor maintenance from p.o. and heavy scaling. In 5 years of ownership, I went through 2 autozone radiators, 3 water pumps, and had to flush that puppy every time that pump was changed. There was heavy scaling every time which I believe caused the water pump failures. My mjs ran all the same components cheaply made from autozone and never a problem. The xj had seen 40,000 more miles though in a shorter lifespan(rest in peace xj). I also think I had a bad head gasket toward the end when pump and radiator were replaced twice within a year and half. The radiator looked near brand new. Pulled the lower hose to bleed the system fast and it looked like red clay. I've burped the system just sitting level on the driveway but I'll definitely jack up the driver side when I get back. Think my buddy has some vacuum system that might work also. I think I might give the cleaning detergent a shot. Was hoping with the rebuild the guy would've cleaned it before installing new parts but who knows. Running out of options. The idle settling at 500rpms after a few seconds has been bothering me also. Used to be closer to 800ish. Guess it's time to start pulling the harness apart and inspecting/testing wires. Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
omega_rugal Posted May 27, 2018 Share Posted May 27, 2018 also use less antifreeze, water moves heat better, unless you live in a very cold climate, no need to run at 50/50... ... are you having performance issues? i have seen people throw stuff at their vehicles because "the needle says it`s overheating" when in fact it`s the sender/gauge malfunctioning...if you can even get close to the engine then is overheating... also check your oiling system, oil reduces friction and helps to move heat away from the engine... is the oil black or burned? or probably just an air pocket, those also tend to drive people crazy... Link to comment Share on other sites More sharing options...
AZJeff Posted May 27, 2018 Share Posted May 27, 2018 If you take the Jeep out on the highway (where you can keep a sustained speed of 40+ MPH, and the engine stays at an acceptable temp, then you can dismiss any issues related to airflow over the radiator, as at that speed, any fans are not needed. That would be a quick test. Just revving the engine up to higher speed for a few minutes won't demonstrate cooling system function correctly, as it takes time for the engine to generate the added heat of higher RPM, and it's takes time for the coolant to absorb that heat and then attempt to transfer it to the air via the radiator. You need a sustained higher engine speed to demonstrate proper water flow conditions. The fact that the engine heats up and cannot dump the heat at higher STEADY RPM makes me inclined to agree with most of the other posters---you are not getting proper water circulation. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted May 27, 2018 Share Posted May 27, 2018 2 hours ago, saveevryjp1998 said: You need to just purge the system of air properly it sounds. Whenever you change a water pump or radiator or drain the coolant you need to burp the system. An open system self purges air in the system. Even with a closed system I have never had to burp it. The only thing that has ever made me get unduly hot has been a bad radiator, a clogged cat a gnarly grade or a bad water pump. My CSF 3 row was crap after one year. I've been using a Spectra OEM single row for almost 2 years, no probs. Link to comment Share on other sites More sharing options...
HOrnbrod Posted May 27, 2018 Share Posted May 27, 2018 35 minutes ago, ParadiseMJ said: An open system self purges air in the system. Exactly. Burping never required in any of the six I've had. If everything is behaving as it should, when the temp gauge reaches 190* - 200*, the thermostat opens, the air is expelled into the expansion tank, the temp gauge drops ~20*, then slowly rises to normal operating temperature. Link to comment Share on other sites More sharing options...
8valvehero Posted May 28, 2018 Share Posted May 28, 2018 My 2 Canadian market MJs did not have aux fans from the factory and do not overheat unless stationary for extended periods. They both have open systems. Do you have an oil temp gauge to help with the diagnosis? It would be handy to know if a hot-running engine is heating the coolant beyond the limit of the system, or if the cooling system is malfunctioning and not cooling the engine properly. Good Luck! Link to comment Share on other sites More sharing options...
SBpunk Posted May 28, 2018 Author Share Posted May 28, 2018 Heading back to town now. I don't have an oil temp gauge but that'd actually be pretty awesome. I plan on swapping to an aw4 with a cooler and gauge if I ever figure this out. Going to hook the system up to a vacuum tomorrow morning when my shop opens unless oriellys has one for rental. I'm honestly thinking about ditching the zj fan and putting the stock electric fan back in. Only two parts that are really "upgrades" left. Guy that does injectors on the forums said he would test my injectors for me. Never wanted to get back from the woods so badly. Just got to remember not to start a project before leaving on vacation hahaha Sent from my PH-1 using Tapatalk Link to comment Share on other sites More sharing options...
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