Figured it out yet. Old post, but first, I’m curious to know how your being notified the engine is overheating. I ask because the divisions on the gauge do not make sense. So if the gauge being around 210 is your only indication, it may not be as bad as you think OEM is 195 deg IIRC.
Explanation: Using the numbers on the gauge as a reference divide between the marks, and you get different divisions. I’m not looking at mine now, but its something like - 100 - small line - big line - small line - 210 - small line - big line - small line - 260. 100 to 210 is 110 difference. Half would be 55. 100 to 260 is 160 half would be 80 making the center 180 not 210. You can try to do the math with the other division lines, nothing seems to work out *sigh* There should be about one needles width between your needle and the 210 line.
If you are overheating though, here is a short checklist, not a complete list, and in no particular order. First make a list of things you have done to narrow the problem. Then…
if you have 4.7l V8, these run hot, many including myself believe the cooling system is underrated (under capacity). If you havent already, check/change the thermostat. I have gotten some bad ones brand new. these knockoff no name Amazeon (you know who I mean) brands are GARBAGE and DESIGNED TO FAIL. Get a Stant, they are no more expensive, and they have a warranty. This should have been done standard practice with pump change. Installing them backwards is a common mistakes, even for seasoned mechanics, so dont overlook it.
Another thing is the V8’s have a hard time bleeding air from the cooling so Chrysler put a bleed valve in the return neck (upper radiator hose). Its tough to remove first time. Its a cap screw, about 10 mm IIRC. I recommend a 3/8 square to hex and a ratchet. Engine needs to be hot, relieve pressure, remove radiator cap, remove the bleeder screw, then run the engine, when the coolant leaks from bleeder hole, its full. reinstall.
If you have clutch fan, with ENGINE HOT BUT NOT RUNNING, try to turn clutch fan by hand. It should be difficult to turn. Sometimes though these will work some, but not well enough, so be advised.
If you have electric fan, or yours has been converted to electric check proper operation, including the fan relay.
If you have hydraulic fan, check the solenoid in the hydraulic fan housing on the fan casing, 12v on the solenoid wire should activate the solenoid. CHECK/CHANGE THE POWER STEERING PUMP. the P/S pump is responsible for running the hydraulic fan on these models. check the pressure using a pressure gauge, and verify you have the correct pressure. Pull the coolant temp sensor on the top front of the engine and the hydraulic fan should goto maximum. You will know because it is extremely loud like train or tornado.
Check/change the coolant temp sensor.
Verify you have at least a %50-%50 mix of coolant. Check overflow reservoir, make sure its at the - MAX- line.
Check/replace the radiator cap, if it doesnt hold pressure truck wont cool.
If all that fails, its possible your transmission is overheating. While rare, this can happen, especially if you are towing. In that case add transmission cooler, and or check/replace BOTH filters in 545RFE.
Some people also install ‘pusher’ fans, they are electric ‘supplement’ fans to help cool the radiator, dont forget to use a relay and properly wire to a thermostat.
K Lewis besides replacing the water pump, what have you checked? Have you ever done a pressure check on your radiator? Have you had the cooling lines flushed? ave you checked the hoses to make sure they are not collapsing? Have you checked the thermostat? Have you checked the fans to make sure that they come on appropriately? Have you replaced the radiator cap? Have you checked to see if you are burning antifreeze? Checked the engine overall to make sure that you do not have any damage to the cylinder head(s)? Let us know what you have checked, replaced and what engine size your WJ is.
- de oldturkey03