Cooling System

[DieselSJ]

Interesting that you're running two stock aux fans, don't know why I hadn't heard of doing that before. Any idea of the CFM of the stock late model fan? I've been wondering what the stock fans pull.

They move a lot (that is a racing term - it means "a lot"). There is a noticeable difference between the early straight blade and the late curved. We actually use the same fans on the oil and trans coolers - makes carrying spares a lot easier.

Edit: If you're running pure-electric fans, how did you accomplish the clutch fan delete and did it involve rerouting the belt?

No belt re-route. Pulled the fan clutch, replaced studs with bolts, slid fan into place.

 

[trevanator]

I think if 240 is the highest temp he sees at the very most then it is not a great cause for concern as long as it cools back down quickly as mine does. Mine will not boil over at 240 but it rarely gets that hot.

Hey John well you know my system probably better than anyone since they are identical and i honestly dont see any issues yet and I am not having problems with the fans as of yet they are performing great all the time so maybe i got one built on the right day lol. however my concern with my stock gauge almost hitting the red is that even though my aftermarket gauge reads about 210 or so when my stocker reads 240 my thermostat gets stuck open so its gotta be hotter than 210 out of the housing but i have had multiple gauges stuck in the coolant coming out of the housing and when the stocker red 210 it was really 185 so i know for sure the stock is off at 210 so maybe the thermostat you might think but no its done the same thing with three different thermostats all the same brand so maybe its the brand if it does it again i am going to try a different brand but yeah its just puzzling i am not immediately concerned because I have no boiling over issues whatsoever and it does cool back down rather quickly once i hit flat ground but its annoying for sure and it could turn into a problem.

as for specs its 4" lift with 32" mudders no lockers just open 3.55 gears in both. i am going to try charging the hills in 3rd next time per some opinions and see if that has any affect we shall see but since my tranny fluid isnt running into the radiator i am doubtful it is the cause of the heating up. if it is then idk how to fix that lol new tranny i guess? or a better or more trans coolers lol

thanks for all the help though guys it gives me things to look at and ideas to go over.

and yes for the bazzzzzziiiiiilllllliiiiiionnnnnnth time the stock fans are better so i am told but i dont wanna mess with a good set up at this point since i do not suspect the fans to be the issues since as someone said here that its at highway speeds and only up hill so it shouldnt be the fans

 

[trevanator]

If this is happening at highway speeds, I'd personally rule out the fan situation unless they are restricting airflow at high speeds. I'd be curious whether you have the correct water pump for your application. While I haven't tried it myself, if you have the pump that has the vanes backwards for your year, it seems reasonable that it would have a temp-climb issue.

Edit: If you're running pure-electric fans, how did you accomplish the clutch fan delete and did it involve rerouting the belt?

That or the new T-stat isn't opening 100% or it doesn't flow as well as some of the others.

If this is happening at lower speeds, then the fans may be suspect. I haven't spent much time exploring Corona, so I can't say I remember where Lincoln is. Guess I could look at a map...

to answer your question about the belt and clutch fan i did not do it myself so dont quote me jeeperjohn can better answer this but to my understanding it is just a replacement pulley there that acts as like an idler pulley so it is just free spinning it is just a dummy so there is no rerouting or anything just a place holder pulley.

that is a thought about the waterpump but it is an oem replacement but aluminum so i am not sure it was the one spec'd for my year and jeep so idk it seems to work fine though if i step on the gas the temp goes down slightly as it is pushing more cool coolant through

since this is the third thermostat i am skeptical that is the issue but it could be the brand

 

[jeeperjohn]

Are you running the shrouds?

 

[trevanator]

What shrouds are you talking about my fans have the red cover shroud type things if thats what youre talking about? I can take a picture and post it or maybe you can show me what you mean on yours either way.

 

[DieselSJ]

You still didn't answer - what temp to you have your fans set to come on at?

 

[hubs97xj]

Shrouds.
http://www.naxja.org/forum/showthread.php?t=1010466

 

[casm]

What shrouds are you talking about my fans have the red cover shroud type things if thats what youre talking about? I can take a picture and post it or maybe you can show me what you mean on yours either way.

The shrouds are black plastic surrounds attached to the radiator that go around the circumference of the fans.

Never heard of or seen red ones before... Those photos may be handy here.

 

[trevanator]

Shrouds.
http://www.naxja.org/forum/showthread.php?t=1010466

Yeah i figured that was what john was talking about so yes i have those.

DieselSJ
my fans come on as soon as the thermostat opens and the fluid pumps through i believe its actually set at about 180 im not sure though it just is a screw that you turn there is no actual numbers it gives

Casm
Yeah the shrouds for this fan radiator set up is different it isnt stock so they are three individual red shrouds

 

[comanche91]

Had the same problem (engine temps going up 30* or so on long grades). Rehabbing the entire cooling system did not help. Turned out to be a clogged cat we found when installing a dual exhaust system. The cat was replaced it with a "test" pipe, and all was golden.

I run a 4.6L Hesco stroker w. many other mods, and for cooling the very best mods for me were:

1. Dual 1997+ 10-blade electric fans. Writeup HERE
2. Reflexxion cowl hood
3. Single core all-alum radiator
4. OEM tranny cooler

 

[trevanator]

Hmmm now that is one I have not heard before.
Would a smog test pick that up though? Or would it still pass with flying colors?
How would I go about checking this?

 

[comanche91]

No smog tests here so I don't know. The engine temps were fine around town and on the highway but always the temp went up under the load of a long uphill grade. Went through the usual cooling system troubleshooting as you did; new rad, water pump, mechanical fan clutch, flush, etc. all no help. In the process of installing headers and a new exhaust system, when we unbolted the cat and looked in the inlet, it was very obviously clogged with a black tar-looking substance. Naturally I eliminated the cat with a test pipe and no more overheating problem going up long grades.

Obviously in Cali you have to pass the smog tests. If your rig has still has the original cat, suggest replacing it w. a universal free-flowing aftermarket cat from
MagnaFlow or another vendor. Or at least open up the inlet and eyeball it.

 

[carves]

I would try this since it's it's cheap and easy...

http://go.jeep-xj.info/HowtoRadiatorRestrictor.htm

Ahhh.........that's what the thermostat is for. Instead of that silly arrangement use the stock 195* thermostat.

That doesn't replace a thermostat, it's in addition to one. He is using a 195*.

It helps reduce drastic tempature swings, the article explains why it works.

JMHO, but I'd rather have the temp swings.

Shouldnt be any drastic temp swings if its done right ....

Whilst it may be seen as a cure .... its more likely the restrictor is a bandaid for the possible combination of too much coolant flow, too much airflow, and an efficient radiator ... or maybe a faulty thermostat that didnt regulate flow properly.

I now sit on 195' all year, except for an occaisional 192' or 198' caused by extreme ambients and driving load - Without having fitted any of the internet witchcraft touted as cooling aids.

Simply a matter of a decent radiator and a fully functioning heavier duty fanclutch (bazillionty billion and one) ..... with a smidgin of effective engine bay venting .... and a useful thermostat.



Wasnt it FFF that had a disclaimer that the stock XJ system should be used in hotter USA areas ???? ..... or does the heavier duty version on their website replace that ???

 

[Sero]

Shouldnt be any drastic temp swings if its done right ....

Whilst it may be seen as a cure .... its more likely the restrictor is a bandaid for the possible combination of too much coolant flow, too much airflow, and an efficient radiator ... or maybe a faulty thermostat that didnt regulate flow properly.

I now sit on 195' all year, except for an occaisional 192' or 198' caused by extreme ambients and driving load - Without having fitted any of the internet witchcraft touted as cooling aids.

Simply a matter of a decent radiator and a fully functioning heavier duty fanclutch (bazillionty billion and one) ..... with a smidgin of effective engine bay venting .... and a useful thermostat.



Wasnt it FFF that had a disclaimer that the stock XJ system should be used in hotter USA areas ???? ..... or does the heavier duty version on their website replace that ???

I agree, it is a band-aid fix. But too many people just throw upgraded parts in hopes that it will fix their problem when it's just creating other problems. Adding high flow parts will just mean the coolant goes through the rad too fast and won't get a chance to cool down. The reason I suggested it was because it was cheap and easy and obviously for some people, it works.
With the exception of an upgraded rad, my cooling system is stock, no restricter here. I had a proplem, I diganosed and replace my fan clutch (not heavy duty) and my truck runs at the right temp.

 

[trevanator]

No smog tests here so I don't know. The engine temps were fine around town and on the highway but always the temp went up under the load of a long uphill grade. Went through the usual cooling system troubleshooting as you did; new rad, water pump, mechanical fan clutch, flush, etc. all no help. In the process of installing headers and a new exhaust system, when we unbolted the cat and looked in the inlet, it was very obviously clogged with a black tar-looking substance. Naturally I eliminated the cat with a test pipe and no more overheating problem going up long grades.

Obviously in Cali you have to pass the smog tests. If your rig has still has the original cat, suggest replacing it w. a universal free-flowing aftermarket cat from
MagnaFlow or another vendor. Or at least open up the inlet and eyeball it.

I will definitely check into this as it seems like the issue you are describing is identical with mine so i am going to check on this maybe pull of the cat and check or maybe just replace it anyways because it is the original. Thanks for the help everyone I do appreciate it all

 

[Darky]

Had the same problem (engine temps going up 30* or so on long grades). Rehabbing the entire cooling system did not help. Turned out to be a clogged cat we found when installing a dual exhaust system. The cat was replaced it with a "test" pipe, and all was golden.

I run a 4.6L Hesco stroker w. many other mods, and for cooling the very best mods for me were:

1. Dual 1997+ 10-blade electric fans. Writeup HERE
2. Reflexxion cowl hood
3. Single core all-alum radiator
4. OEM tranny cooler

I do hope that after your "test" was completed, you replaced the "test" pipe wit a functioning cat...smog checks or not, it's federal law that mandates the cat on all vehicles originally equipped with one. Plus, we don't need to be seen as promoting cat removal when there's no benefit other than saving a little money every 5-10 yrs.

trevanantor: Try replacing the cat as comanche91 suggested. Unfortunately we get screwed in CA by having to by CARB certified cats which cost 3x as much as the non-stamped identical counterpart.

 

[comanche91]

I do hope that after your "test" was completed, you replaced the "test" pipe wit a functioning cat...smog checks or not, it's federal law that mandates the cat on all vehicles originally equipped with one. Plus, we don't need to be seen as promoting cat removal when there's no benefit other than saving a little money every 5-10 yrs.

I did. It functions quite well too.

 

[trevanator]

I do hope that after your "test" was completed, you replaced the "test" pipe wit a functioning cat...smog checks or not, it's federal law that mandates the cat on all vehicles originally equipped with one. Plus, we don't need to be seen as promoting cat removal when there's no benefit other than saving a little money every 5-10 yrs.

trevanantor: Try replacing the cat as comanche91 suggested. Unfortunately we get screwed in CA by having to by CARB certified cats which cost 3x as much as the non-stamped identical counterpart.

lol i know california doesnt seem to like us much it must be a they hate everyone thing theyre just jealous they arent as cool as us damn politicians and theyre rules.