ghetdjc320 Posted June 6 Share Posted June 6 14 hours ago, 75sv1 said: I do have the triple fans on my 2000 XJ. I do not note any overheating. I used the Dirt Bound fan frame and SPAL 10 inch fans. I do mainly open road, some intown. I think it cools a bit better while driving. I do have my concerns if I was to be in heavy stop and Go traffic. Also, if wheeling. The stock electric fan does flow a lot better than the SPALs. I did look into running two stock electric fans. A RH and a LH drive. Couldn't come up with a RH drive fan. From memory, SPAL 10 inch ones are 800 cfm(??? maybe lower). Stock ones are 1100 to 1200 CFM. There are some SPAL 10 inch ones that put out a higher CFM. They don't quite fit. Once you get to about 45mph, the airflow from driving should exceed the flow of most e fans. The real test for e fans comes from idling in traffic on hot days with accessories on. The battery will provide reserve capacity but only at about 12v vs the typical 13.8-14 from the alternator. The performance difference is noticeable for e fans. Once the engine operating speed comes up, so does the alternator output and the fans may provide enough flow. The XJ/MJ just wasn’t designed to run all e fans on the stock cooling system. If the radiator capacity and efficiency is increased, the coolant passages are clean, the water pump flow is appropriately matched to the radiator capacity and engine size, then e fans could be used provided they can churn out sufficient flow under full alternator load at idle. But most setups simply can’t provide the CFM of the factory setup at idle. When idling, the engine electrical is basically at its weakest when the e fan load is at its peak. Many aftermarket manufacturers spec their fan CFM rates at specific voltage which are simply not attainable at idle with most stock MJ/XJ electrical system. Link to comment Share on other sites More sharing options...
BEEDOSAUCE Posted June 20 Author Share Posted June 20 On 6/4/2025 at 9:59 PM, ghetdjc320 said: Stock electrical probably can’t supply enough amperage to keep a steady 14v to the fans when idling. The OE or similar design works best on most stock setups. update, so I had changed the water pump and had the heads resurfaced because they were warped and had even installed stock clutch fan/electric fans back on the truck but it still overheats. any ideas why?? i’ve never had any overheating issues until now Link to comment Share on other sites More sharing options...
89 MJ Posted June 21 Share Posted June 21 Are you sure the cooling system does not have any air in it? How worn out is the stock fan clutch? Did you verify that the thermostat is opening? What gauge are you using to verify the temperature? The stock gauges are not always very accurate. Link to comment Share on other sites More sharing options...
BEEDOSAUCE Posted June 21 Author Share Posted June 21 4 hours ago, 89 MJ said: Are you sure the cooling system does not have any air in it? How worn out is the stock fan clutch? Did you verify that the thermostat is opening? What gauge are you using to verify the temperature? The stock gauges are not always very accurate. honestly I had all my mechanic do that stuff so i’m not sure i can answer, but the gauge on the dash board goes all the way near the second to last line whenever i go highway speeds. the clutch fan isn’t worn out much because i had it installed before and it did a great job at cooling the truck down so I'm just stumped on what it could possibly be Link to comment Share on other sites More sharing options...
BEEDOSAUCE Posted June 21 Author Share Posted June 21 4 hours ago, 89 MJ said: Are you sure the cooling system does not have any air in it? How worn out is the stock fan clutch? Did you verify that the thermostat is opening? What gauge are you using to verify the temperature? The stock gauges are not always very accurate. I didn’t have a thermostat before either due to the previous owner but i had my mechanic install a new one and purge out the cooling system of any air Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 21 Share Posted June 21 What water pump did you install? Iirc, there is a reverse rotation and standard rotation for the 4.0. Both fit but installing the wrong one can cause flow issues Link to comment Share on other sites More sharing options...
BEEDOSAUCE Posted June 21 Author Share Posted June 21 4 hours ago, ghetdjc320 said: What water pump did you install? Iirc, there is a reverse rotation and standard rotation for the 4.0. Both fit but installing the wrong one can cause flow issues honestly i’m not sure, I had my mechanic provide and install it for my since it was already at the shop getting the heads repaired. how could i tell the difference? Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 21 Share Posted June 21 This may sound basic, but have you opened the radiator cap and checked your coolant level recently? Is your radiator getting hot on both sides? Link to comment Share on other sites More sharing options...
Pete M Posted June 21 Share Posted June 21 go buy an inferred thermometer. any hardware or automotive store will have them. Link to comment Share on other sites More sharing options...
BEEDOSAUCE Posted June 21 Author Share Posted June 21 11 hours ago, ghetdjc320 said: This may sound basic, but have you opened the radiator cap and checked your coolant level recently? Is your radiator getting hot on both sides? I have!! every time I would go out I’d make sure to check if it was filled up and if not i’d refill it up. I’m just genuinely stumped because I feel as if i’ve done all the proper steps to fixing it. The only thing I can think of is if my mechanic didn’t do a good job Link to comment Share on other sites More sharing options...
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