Mudderoy I got a question for you.

[ike]

Just ran across a post ‘bout fan override switch and saw where you were having another problem.

Running hot going down the hwy. Me too.
I’ve got new everything in the cooling system, and can run all day on the trails with the a/c on with no problem. But I can’t run down the hwy over ‘bout 57 mph without it getting past 220* after about 20 min.

So did you resolve your issue with that problem? :pray:

I'm thinking it's gotta be a air flow issue with my jcr bumper and winch, but idk, still scratching my head on this one. :bang:

[jccatt]

Lift the hood 20mm at the back to let more air flow. Lowered my temp by 10 degrees.

[xj4life2]

Lift the hood 20mm at the back to let more air flow. Lowered my temp by 10 degrees.

Did the same thing , 1/2 in lift in the rear and I agree it works, actually put a ribbon on there and a low speed it sucks air in and at high, blows out just like cowl induction should !!!

What is you gear ratio / tire size ? that may have something to do with it also your fan clutch, check to be sure its locking up the way it should.

[4.3LXJ]

Mark

Just got back with a radiator for HUM WEE that has Renix XJ tanks on it. I found a fan switch for it that turns on at 187° instead of the stock 198°

[ike]

well like i said...it's all new and working :rolleye0012:
new 3 core radiator.
new water pump (reverse rotation 4 sure)
new stant 195* t-stat, and new stant 16# cap
new ecs.
new fan clutch.
e-fan works when it should and when i flip the switch.
heater core is not stopped up.
all new hoses. (it's not sucking the lower hose shut @ 2200 rpm)
a/c condensor, trans cooler, and p/s cooler all clear and flowing good air @ idle. (hard to ck @ 65 mph)

oh but @ 3000 to 4000 rpm you can really hear the engine fan and it seems to cool down a little but i've only been up a couple of hills that were long enough and steep enough for it to down shift and maintain that speed.

can drive it all day with a/c on as long as i don't go any faster than 'bout 57 mph.

so i see some one else (mudderoy) has/had a similer problem with his xj, have yet to hear from him.

don't remember having this problem @ end of summer last year, but i wasn't driving it too much. but when i did it was on the hwy for at least 50 miles...only thing i've changed was the front bumper :out:
besides all the new cooling stuff.

would be intersted in the part # for that ecs that turns on fan @ what was it 187* not that it would help at this time.

as to the hum wee radiator with xj tanks??? did you have that made or what?
and just what does that mean? i've been thinking of trying to get a 4 core made out of aluminum but haven't ck any on it yet...seems like it would be a tight fit.

[Mudderoy]

No I still have the highway heat creep issue. It isn't air flow at least not blockage from custom bumper, winch and 4 6" KC lights, believe it or not. I had the same issue with stock 1998 front bumper. Problem started after lift tires and wheels.

It may be air flow due to the air passing under and over the nose of the Jeep since it is so narrow. I need to put something down low like an air damn to see if I can force more air through the radiator.

[Mudderoy]

I see you have 35" tires and 4.56 gears. I was tempted to go with 35" tires just so I could get my RPMs down to normal on the highway. I've got 32" tires and 4.56 gears. I run about 3000 rpm at 80 mph lol

[jeepxj95]

i cant hear my clutch fan any more :( that could be my over heating issue in traffic and on the trails

[ike]

air flow being deflected under instead of thru...well maybe, but at hwy speed you would think that enough air would be going through the grill.
do you have have a front skid, factory or other?

i had waited for 6 mo trying to get 33" bfg km2's (factory back order no one had any anywhere) so i went with the 35's. now that i've got them i like them, just wish i'ld gone with 4:88's. went back an forth tryin to decide which way to go as i was building my xj, decided 4:56's an 33's was the way to go.
then got stuck on 35's.

2200 @ 55 ain't bad...but wish i could drive 70 with the stinkin a/c on without it gettin hot.

i've seen a pic of a lifted jeep (not an xj) with a lexan scoop on the front bumper covering the winch on 3 sides to direct air into the grill so they could run down the hwy, it was a street legal trail rig. but it's something to think about.

[Mudderoy]

air flow being deflected under instead of thru...well maybe, but at hwy speed you would think that enough air would be going through the grill.
do you have have a front skid, factory or other?

i had waited for 6 mo trying to get 33" bfg km2's (factory back order no one had any anywhere) so i went with the 35's. now that i've got them i like them, just wish i'ld gone with 4:88's. went back an forth tryin to decide which way to go as i was building my xj, decided 4:56's an 33's was the way to go.
then got stuck on 35's.

2200 @ 55 ain't bad...but wish i could drive 70 with the stinkin a/c on without it gettin hot.

i've seen a pic of a lifted jeep (not an xj) with a lexan scoop on the front bumper covering the winch on 3 sides to direct air into the grill so they could run down the hwy, it was a street legal trail rig. but it's something to think about.

Well I'm thinking that as the Jeep goes faster the air has a easier time going above and below the nose. Also the more heat is generated.

I have a factory skid but I have not reinstalled it yet.

[ike]

me too, looks like i'll have to take frt sway bar off to use it as the re lift uses drop brackets for the bar mounts.
just wondering if the skid would help or hurt with the direction of the air flow.

we need a wind tunnel an some smoke...lol

[LizardRunner]

Tony, I've been thinking on your overheating problem and I think you are experiencing a quirk of aerodynamics. the front profile of the XJ is sorta like a jet, at higher speeds you are producing a cone of air flow that goes above and below the radiator, just like a jet going super sonic. This cone actually creates a no air through the radiator situation. If you reinstall the front skid, you should find better air flow through the radiator since there will be a drop in pressure inside the engine compartment, this will suck air in through the radiator instead of allowing all of it to go over the hood or under the vehicle. physics is cool.

[ike]

i ken put mine on maybe tomorrow and find out if physics is the way to cool our xj's...lol

[LizardRunner]

I'm interested to know, I've been following Tony's problems and trying to figure out what is going on. Then I got the idea of doing a virtual wind tunnel investigation of the front end of his jeep.

[4.3LXJ]

Well I'm thinking that as the Jeep goes faster the air has a easier time going above and below the nose. Also the more heat is generated.

I have a factory skid but I have not reinstalled it yet.

My position exactly. In fact the air underneath is an area of high pressure, which is why many cars have air dams, as well as to reduce air drag from turbulence.

[Weldmen]

This is a great thread! I am at my seats edge to hear how it all turns out, and what was the best fix. :D

[ike]

Well didn't physics work out for me. Stock frt skid won't fit with my lift. Steering linkage interference. Tried to mod skid to fit, but by the time I get it to fit there wouldn't be much left.
So now on to plan B.

[LizardRunner]

might have to fab one up. Use cardboard to make the pattern, that way you can fit it easily. I'd try to get the high end up close to the bottom of the front bumper, as wide as possible then taper it back, trimming around the suspension pieces. I'll be making mine from 18 gauge steel but I would think 20 gauge would also work (think the factory ones are 20 gauge) if you could do some bead rolling you can stiffen a large flat panel quite a bit.

[ike]

that's the plan...but i only got 1/8" an 3/16" sheet steel in the shop.
oh well...show me the beef!!!

[4.3LXJ]

that's the plan...but i only got 1/8" an 3/16" sheet steel in the shop.
oh well...show me the beef!!!

We talking hamburgers here or what:rolleye0012:

[LizardRunner]

1/8" would work dang well.

[ike]

Time for today’s update…

Since making the frt skid requires more fab time than i had, I did this instead. :rolleye0012:

Cut a piece of sheet metal, 8 1/2” x 34”.
Trimmed to match profile of pre runner bars and grill.
Mounted to light mounts on pre runner hoop and used existing holes in bumper for mounting lights. (on those bumpers without pre runner bars)
Made 2 stands out of 1/8”x1” flat stock. 11” tall with 2-1” 90*bends for mounting (both the same way).

Bolted it up, took it out for the hwy test. :pray:

I can drive 70 mph w/ac on and temp stays just under 220*during the heat of the day!!! (extended hwy test just to make sure) :D

Now all I gotta do is drill a hole so I can plug in my winch control, and paint it black to match the xj.

Maybe next week I can fab up the rear bumper, swing out tire carrier, tc skid, oh and the frt skid. :smiley-gen165:

[Mudderoy]

Time for today’s update…

Since making the frt skid requires more fab time than i had, I did this instead. :rolleye0012:

Cut a piece of sheet metal, 8 1/2” x 34”.
Trimmed to match profile of pre runner bars and grill.
Mounted to light mounts on pre runner hoop and used existing holes in bumper for mounting lights. (on those bumpers without pre runner bars)
Made 2 stands out of 1/8”x1” flat stock. 11” tall with 2-1” 90*bends for mounting (both the same way).

Bolted it up, took it out for the hwy test. :pray:

I can drive 70 mph w/ac on and temp stays just under 220*during the heat of the day!!! (extended hwy test just to make sure) :D

Now all I gotta do is drill a hole so I can plug in my winch control, and paint it black to match the xj.

Maybe next week I can fab up the rear bumper, swing out tire carrier, tc skid, oh and the frt skid. :smiley-gen165:

This sound promising, but I'm going to have to read it a few times to understand where you put this.

[ike]

over the winch, grill wide, with this bumper http://www.jcroffroad.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=1XJFWNPre&Category_Code=XJB
tapered to fit profile of the bars, and grill. 1/2" space between the grill and part i made...34" long.
last 2 pics in link are where it's mounted to bar, big lights.
bumper has two holes for mounting lights that are right @ the left and right side of the grill, perfect spot to mount uprights.
turns out looking like a winch cover, can't really see it unless your right there looking at it.

[4.3LXJ]

:worthlesspics:

[ike]

here ya go...

http://i1223.photobucket.com/albums/dd506/jjw2w/jeep/Picture002.jpg

http://i1223.photobucket.com/albums/dd506/jjw2w/jeep/Picture001.jpg


http://s1223.photobucket.com/albums/dd506/jjw2w/jeep/?action=view&current=Picture001.jpg#!oZZ1QQcurrentZZhttp%3A%2F% 2Fs1223.photobucket.com%2Falbums%2Fdd506%2Fjjw2w%2 Fjeep%2F%3Faction%3Dview%26current%3DPicture002.jp g

[LizardRunner]

ahhhh, a topper for the winch, sort of an upper radiator air director.

[ike]

yep, a couple hours of thought and fab work, and it works great. add some lights and most wouldn't even notice it.

been looking @ making the frt skid/air deflector...i think if i come off the frt bottom edge of the frt bumper, about an 1" lower than the pitman arm’s lowest point is going to be about all the angle i'll be able to get for a lower air director without loosing too much approach angle.

[ike]

Well for those who are keeping up with this…

Got the front skid made and installed,
3/16 plate ‘bout 34” wide (I forget how long) 2” bolted to frt bumper, bent down ‘bout 30* @ 2” mark. Hangs down 7” @ rear sway bar mount.

It didn’t help with the cooling issue, in fact it may of hurt,
but I also installed 2 kc driving lights, so I’ll have to remove the frt skid and see if it’s the lights or the skid that changed the air flow again.

Plan is to move the driving lights to the outside mounts on the wing and put 2 kc day lighters in the mid mounts.(where the driving lights are now)

On a side note got the rear bumper and swing out tire carrier made and installed. It turned out good.

http://s1223.photobucket.com/albums/dd506/jjw2w/jeep/?action=view&current=Picture008-1.jpg

[4.3LXJ]

That has been my experience too. A big skid in the front does not help. I still maintain that our radiator design is the culprit. ZJs which have a radiator that is more square have far less cooling issues with the same running gear. If I had it to do over, I would have redesigned the front cross member and put a radiator in that was like the ZJ radiator.

[bigjim350]

Well after my experiment between 1, 2, and 3 core radiators, I think you would run much cooler with a 1 core rad. Less hot water in it, better air flow, and less hot metal. Its worth a shot, since I know tony knows somebody who would let him use a rad, and I'm sure you can find somebody also.

[ike]

"If I had it to do over, I would have redesigned the front cross member and put a radiator in that was like the ZJ radiator."

funny...i was thinking the same thing. :smiley-laughing021:

[ike]

Got 1 more trick up my sleeve, gonna try a set of lebaron hood vents, well just because I don’t have any.

If that don’t work, will try something else after I think of something else to try.(read a few adult beverages later)

First up is relocating the solenoid box for the winch. Which means relocating the air filter to the passenger side cowl, as it seems that’s the only places big enough to house either if moved.

Or i could just not use the A/C goin down the hwy...NOT!

[ike]

Today I pulled off the frt skid to confirm that it has changed the airflow threw the radiator.
With frt skid off and the wing over the winch, hwy cooling with a/c on is not an issue. Stayed below 220* for 65 miles in 94* heat.
Frt skid back on and I can only go 16 hwy miles before temp is up to 220* and climbing.

Since I haven’t gotten my lebaron vents yet I decided to try something else.
I put some spacers in between the hood hinge and hood giving me ¾” opening across the rear of the hood.
This helped to a point, getting almost 40 hwy miles before the temp hits 220* with a/c on. Where it really helped was @ lower speeds, it cools down much quicker now.

At 57mph it will stay below 220* with a/c.

As for creating a low-pressure area under a lifted Cherokee… while I’m not an engineer, this ain’t NASCAR, I don’t think we’ll ever be able to generate the kind of low-pressure we’re looking for under a vehicle lifted that far from the road surface, but I’ve been wrong before. I do know that adding the frt skid to mine changed something with the airflow. :confused:

As for the Champion radiator…I'm intersted, but I don’t see how going to aluminum 3-core radiator over the CSF 3-core is going to solve the problem as it seems to be an airflow problem @ speed. Unless the radiator just can’t dissipate the heat generated by the condenser. Someone with the same problem should get one and try it. :wink:

Looking at the frt skid, thinking of drilling some 1” holes in it to see if that helps with its issue.

Also thinking of running with the hood off, before the holes in the skid and after the holes just to see if it makes any difference. :crazy:

[Mudderoy]

Today I pulled off the frt skid to confirm that it has changed the airflow threw the radiator.
With frt skid off and the wing over the winch, hwy cooling with a/c on is not an issue. Stayed below 220* for 65 miles in 94* heat.
Frt skid back on and I can only go 16 hwy miles before temp is up to 220* and climbing.

Since I haven’t gotten my lebaron vents yet I decided to try something else.
I put some spacers in between the hood hinge and hood giving me ¾” opening across the rear of the hood.
This helped to a point, getting almost 40 hwy miles before the temp hits 220* with a/c on. Where it really helped was @ lower speeds, it cools down much quicker now.

At 57mph it will stay below 220* with a/c.

As for creating a low-pressure area under a lifted Cherokee… while I’m not an engineer, this ain’t NASCAR, I don’t think we’ll ever be able to generate the kind of low-pressure we’re looking for under a vehicle lifted that far from the road surface, but I’ve been wrong before. I do know that adding the frt skid to mine changed something with the airflow. :confused:

As for the Champion radiator…I'm intersted, but I don’t see how going to aluminum 3-core radiator over the CSF 3-core is going to solve the problem as it seems to be an airflow problem @ speed. Unless the radiator just can’t dissipate the heat generated by the condenser. Someone with the same problem should get one and try it. :wink:

Looking at the frt skid, thinking of drilling some 1” holes in it to see if that helps with its issue.

Also thinking of running with the hood off, before the holes in the skid and after the holes just to see if it makes any difference. :crazy:

msmoorenburg is having the same issue with his. He is going to try a all metal one core radiator.

That's an interesting data point about the front skid. Having it on and it getting hot faster doesn't make sense. I'll have to think about that one.

[xj4life2]

msmoorenburg is having the same issue with his. He is going to try a all metal one core radiator.

That's an interesting data point about the front skid. Having it on and it getting hot faster doesn't make sense. I'll have to think about that one.

The reason I got rid of my skid was for same reason it ran hotter with it on , now the dimple dye theroy sounds like a plan to me

[ike]

Since it was easier and quicker to pull the hood than drill a bunch of 1” holes…

At speeds above 60 mph no change in hwy temps with the hood off, but I could verify that the electric cooling fan does run all the time.

Other observations…I was surprised how much the engine moves around driving down the road, even with what appears to be good mounts. (I see a set of brown dogs in the mail)
Cool down time was really quick though when I stopped for gas.

Also if speed is kept below 60 mph the temps stay down around 210*.

So I think I have to change my theory…to it’s not an airflow issue, it’s got to be a thermal efficacy problem.

Not that I’m convinced that the Champion 3-core aluminum radiator is gonna be the cure all, but it is a fact that the thermal efficacy of aluminum is better than copper as in the CSF 3-core.

Which brings up another question…
Is a XJ radiator just too small for a lifted, big tired 4.0 running down the hwy with the a/c on? I guess $200.00 will answer that question.

I don’t know, so I’m gonna go put my hood back on and drill some holes in the skid. (I don’t have a way to dimple die it)

[Mudderoy]

Since it was easier and quicker to pull the hood than drill a bunch of 1” holes…

At speeds above 60 mph no change in hwy temps with the hood off, but I could verify that the electric cooling fan does run all the time.

Other observations…I was surprised how much the engine moves around driving down the road, even with what appears to be good mounts. (I see a set of brown dogs in the mail)
Cool down time was really quick though when I stopped for gas.

Also if speed is kept below 60 mph the temps stay down around 210*.

So I think I have to change my theory…to it’s not an airflow issue, it’s got to be a thermal efficacy problem.

Not that I’m convinced that the Champion 3-core aluminum radiator is gonna be the cure all, but it is a fact that the thermal efficacy of aluminum is better than copper as in the CSF 3-core.

Which brings up another question…
Is a XJ radiator just too small for a lifted, big tired 4.0 running down the hwy with the a/c on? I guess $200.00 will answer that question.

I don’t know, so I’m gonna go put my hood back on and drill some holes in the skid. (I don’t have a way to dimple die it)

That's where I was in all of this. There just seems to be too much heat for the cooling system to dissipate it all. I'm going the route of removing the transmission from the radiator, dropping the amount of heat being introduced.

With all of us working this we should find an answer.

[ike]

For what it's worth, I’ve already removed the trans cooler from the radiator to just the after market cooler. Didn’t help the engine temps, but my trans is much cooler for it at all times. Same for my p/s. Added a factory ZJ trans cooler in the return line. No more p/s hot wine ever. I didn’t ck the running temp before I put it in, but it now runs @ 150* without the cooling fan and 130* with the fan on in this heat, it works for sure without the fan on.

As far as needing the coolant temp to warm up the trans in the winter. I’ve never had it be an issue in TX. My '00 7.3 dually 4x4 trans cooler didn't go into the radiator from the factory, and in the heat, in traffic 220* was the norm. I’ve since replaced that cooler with a cooler from a 6.0 (almost 3 times larger) and have never seen over 170* in the heat, traffic or when pulling a heavy trailer. In the winter it only takes about 12 miles to get to 130*. (First # on my gauge but second mark) and runs around 145-150* after warmed up (winter).

I read your install on your trans gauge, if I read correctly it’s inline before the cooler. After the cooler gives you a much steadier reading, I don’t think it really matters. Mines not in the pan either, but in a test port in the trans.

Have to pull the frt skid to drill them holes. Tried layin on my back and doin it… cost me two ¼” bits.

I’m not sold on the single core radiator…think it will lead to running hot @ low speeds with a/c as well. I replace the factory 2-core with a 3-core CSF. Solved low speed heating issue. All was good till the lift, tires, and gears.

Time will tell.

[Mudderoy]

For what it's worth, I’ve already removed the trans cooler from the radiator to just the after market cooler. Didn’t help the engine temps, but my trans is much cooler for it at all times. Same for my p/s. Added a factory ZJ trans cooler in the return line. No more p/s hot wine ever. I didn’t ck the running temp before I put it in, but it now runs @ 150* without the cooling fan and 130* with the fan on in this heat, it works for sure without the fan on.

As far as needing the coolant temp to warm up the trans in the winter. I’ve never had it be an issue in TX. My '00 7.3 dually 4x4 trans cooler didn't go into the radiator from the factory, and in the heat, in traffic 220* was the norm. I’ve since replaced that cooler with a cooler from a 6.0 (almost 3 times larger) and have never seen over 170* in the heat, traffic or when pulling a heavy trailer. In the winter it only takes about 12 miles to get to 130*. (First # on my gauge but second mark) and runs around 145-150* after warmed up (winter).

I read your install on your trans gauge, if I read correctly it’s inline before the cooler. After the cooler gives you a much steadier reading, I don’t think it really matters. Mines not in the pan either, but in a test port in the trans.

Have to pull the frt skid to drill them holes. Tried layin on my back and doin it… cost me two ¼” bits.

I’m not sold on the single core radiator…think it will lead to running hot @ low speeds with a/c as well. I replace the factory 2-core with a 3-core CSF. Solved low speed heating issue. All was good till the lift, tires, and gears.

Time will tell.

Ahhh thanks. Well at least now I won't be disappointed when it doesn't resolve the heat creep problem. I wouldn't mind having a cooler transmission temp though.

[ike]

dang look what i found...
Amazon.com: 3 Row All Aluminum Replacement Radiator for the Jeep Cherokee, Jeep Wagoneer, Jeep Comanche, and Jeep J-Series - Manufactured by Champion Cooling Systems, Part Number: 78: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51xiW4KMBEL.@@AMEPARAM@@51xiW4KMBEL
and site gets $ too

[Mudderoy]

dang look what i found...
http://www.amazon.com/Aluminum-Replacement-Radiator-Cherokee-Wagoneer/dp/B0054PR6A8/ref=sr_1_1?ie=UTF8&s=automotive&qid=1309224465&sr=8-1
and site gets $ too

It's $5 cheaper from the Champion site, it is however out of stock :D

:link: (http://www.championradiators.com/page/419843582)

[ike]

my point...

[ike]

Ok so after 14 strategically placed 1 1/2” holes in the frt skid, ¾” gap across the back of the hood, and the winch wing/air foil…

In 100+* heat today I could drive all day @ 60 mph with a/c and temp was just barely past 210*.
Bump the speed up to 65 mph and temp went up to just below the 220* mark and stayed there.
I didn’t try 70 as I had enough information for myself @ that point.

I guess I have to change my theory to it’s got to be a combo of both…
Airflow, the thermal efficiency of a radiator that is too small for the 4.0 in a XJ with a big lift and big tires trying to run at speed down the interstate.

My hood vents should be here sometime next week so next test will have to wait.
As it is now I can drive 65 mph for 2 hrs to Barnwell Mt for the weekend with no problem.