Rubber Mat between radiator and engine; Improved Air Flow Through Radiator?

[Mudderoy]

So I was just talking to a guy with a 2001 XJ (2WD) and he was asking me about the rubber mat that is under the engine. I told him I never had one.

Is this a 2WD only item? I can't help but think that his would help my air flow situation on the highway.

Does anyone have the correct name for this part, or perhaps a part number?

He said it's like $15 and frankly I'd like to try it

[rguignard]

mine had it tony and so did patricks

[freegdr]

first thing i tore of off mine

[Mudderoy]

Found it!

55174736 shield underbody. Suppose to assist in MPG

[Mudderoy]

Ok I think I know why mine didn't come with one, I had a factory skid plate. :boohoo:

Does the rubberized guard look like this?

http://i562.photobucket.com/albums/ss64/dillondiesels/Jeep%20Cherokee/IMG_0713.jpg

http://i562.photobucket.com/albums/ss64/dillondiesels/IMG_0492.jpg

[rguignard]

patricks has the skid to and he had rubber under that

[cantab27]

rubber on the jeep..mmmm must make wheeling safer????

[bluedragon436]

I don't know what the proper name is for it, but my 98 had one... took it off when I lost my radiator cap doing the flush a few months back... haven't had any temp issues since I removed it... has been running pretty much the exact same temps.. but I was thinking about it as I was taking it off my Jeep, was wondering if that might be something that could help yours..

[steph74]

yes I had the nasty rubber mat as well as the skid guard
It was falling appart so i removed it totally after I was told that it would not affect anything..... wether it was true or not, i will never know now ;)

[Mudderoy]

yes I had the nasty rubber mat as well as the skid guard
It was falling appart so i removed it totally after I was told that it would not affect anything..... wether it was true or not, i will never know now ;)

Ahhh excellent. If someone has one :camera: I'd love to see what it looks like. I'm trying to resolve my running hot problem.

[freegdr]

Ahhh excellent. If someone has one :camera: I'd love to see what it looks like. I'm trying to resolve my running hot problem.this mat will not help with running hot issue its more of a splash guard to keep water and road debris from hitting in the bottom of the engine bay running warm probs either clutch fan ,clogged radiator,water pump ears wore off,aux fan no operational and so on,also seeing you automatic they are cooled thru rad so if there running warm its going to transfer heat thru the rad to colling system also.just m2cw

[freegdr]

http://www.jeepsareus.com/p/CHEROKEE/5505523.html

[bluedragon436]

this mat will not help with running hot issue its more of a splash guard to keep water and road debris from hitting in the bottom of the engine bay running warm probs either clutch fan ,clogged radiator,water pump ears wore off,aux fan no operational and so on,also seeing you automatic they are cooled thru rad so if there running warm its going to transfer heat thru the rad to colling system also.just m2cw

All of these parts have been replaced/upgraded on his XJ. He has a high flow water pump, a 3 core rad, GC HD main fan clutch and external trans cooler. He has replaced any part that can possibly be replaced, with the exception of I don't know if he has replaced the aux. fan, but I do know that he sad he has checked it multiple times.

[freegdr]

All of these parts have been replaced/upgraded on his XJ. He has a high flow water pump, a 3 core rad, GC HD main fan clutch and external trans cooler. He has replaced any part that can possibly be replaced, with the exception of I don't know if he has replaced the aux. fan, but I do know that he sad he has checked it multiple times.what is he calling running warm as in temp?????????

[Mudderoy]

this mat will not help with running hot issue its more of a splash guard to keep water and road debris from hitting in the bottom of the engine bay running warm probs either clutch fan ,clogged radiator,water pump ears wore off,aux fan no operational and so on,also seeing you automatic they are cooled thru rad so if there running warm its going to transfer heat thru the rad to colling system also.just m2cw

Clutch fan replaced with heavy duty grand Cherokee
Radiator checked and verified excellent flow (and 3 core)
Water pump new and high flow (flowkooler)
aux fan running great and even have a bypass switch
13k BTU B&M transmission cooler IN ADDITION to factory trans cooler

Oh and before you go the route of blocked air flow due to lights and winch, I had the same problem without all that stuff.

Now you're up to date. :D

This has been a multi-year battle and I've spent several hundred dollars. Current thinking from several members here is there isn't enough of a vacuum behind the radiator. Placing something under the engine bay may help that situation and force more air through the radiator at highway speeds.

[freegdr]

Clutch fan replaced with heavy duty grand Cherokee
Radiator checked and verified excellent flow (and 3 core)
Water pump new and high flow (flowkooler)
aux fan running great and even have a bypass switch
13k BTU B&M transmission cooler IN ADDITION to factory trans cooler

Oh and before you go the route of blocked air flow due to lights and winch, I had the same problem without all that stuff.

Now you're up to date. :D

This has been a multi-year battle and I've spent several hundred dollars. Current thinking from several members here is there isn't enough of a vacuum behind the radiator. Placing something under the engine bay may help that situation and force more air through the radiator at highway speeds.

try this start xj and place a pge from the news paper to the grill if the factor fan holds it to the grill youve got plenty of flo what temp are you calling warm and when are you warm sitting or driveing ?????????

[freegdr]

mine will hold a bath towel to the grill and im all stock and in traffic i get a little warm i just turn the ac on to get the aux fan on

[freegdr]

Clutch fan replaced with heavy duty grand Cherokee
Radiator checked and verified excellent flow (and 3 core)
Water pump new and high flow (flowkooler)
aux fan running great and even have a bypass switch
13k BTU B&M transmission cooler IN ADDITION to factory trans cooler

Oh and before you go the route of blocked air flow due to lights and winch, I had the same problem without all that stuff.

Now you're up to date. :D

This has been a multi-year battle and I've spent several hundred dollars. Current thinking from several members here is there isn't enough of a vacuum behind the radiator. Placing something under the engine bay may help that situation and force more air through the radiator at highway speeds.you say you have a extra cooler your still running thru the rad also then to coolers correct

[Mudderoy]

mine will hold a bath towel to the grill and im all stock and in traffic i get a little warm i just turn the ac on to get the aux fan on

lol with all my modifications mine doesn't even think about getting hot at idle or anything up to about 45 miles per hour. 70 mph for about 12 miles it gradually creeps up to around 225 and stays there until I slow down. My mods have helped it, just not resolved it.

It seems to be an air flow issue that occurred after I lifted the Jeep and put the larger tires on it. If this is true then it may be that the air damn was raised above the effective range to force the air through the radiator. That radiator is so skinny anyway.

It is very easy to feel the air flow through my radiator at idle, but of course there isn't any running warm problems there.

A CFM measuring device at 70 mph would probably tell me what I needed to know.

I am looking at the 4600 CFM 3 electric fan setup from DirtBound Offroad as a possible solution as the coolant temp runs near normal (210) with the A/C off and the AUX fan switched on (via my bypass).

[freegdr]

when running down the road colling fans are not a factor , has a manual gauge ever been installed and driven air gonna go thru faster than any fan can pull it thru

[freegdr]

after lift and larger tires motors going to work harder to create movement has any regearing been done air intake modes or exhaust mods ,cat poss part clogged???????????

[Mudderoy]

when running down the road colling fans are not a factor , has a manual gauge ever been installed and driven air gonna go thru faster than any fan can pull it thru

Yep I've heard that before and that's why I went through all the other stuff instead of throwing fans at it to begin with, but read what I said.

It runs hot (not over heat) at 70 mph with A/C on. It runs a little cooler with the A/C off, but with A/C off and AUX fan in bypass (ON) it runs nearly normal.

So this means there is an air flow issue and it also means that the AUX fan is pulling MORE air through the radiator AT highway speeds. So it means the fans DO make a difference.

It could be that in my configuration what it does is the aux fan creates a vacuum behind the radiator and is causing more air to be directed through the radiator.

[freegdr]

lol with all my modifications mine doesn't even think about getting hot at idle or anything up to about 45 miles per hour. 70 mph for about 12 miles it gradually creeps up to around 225 and stays there until I slow down. My mods have helped it, just not resolved it.

It seems to be an air flow issue that occurred after I lifted the Jeep and put the larger tires on it. If this is true then it may be that the air damn was raised above the effective range to force the air through the radiator. That radiator is so skinny anyway.

It is very easy to feel the air flow through my radiator at idle, but of course there isn't any running warm problems there.

A CFM measuring device at 70 mph would probably tell me what I needed to know.

I am looking at the 4600 CFM 3 electric fan setup from DirtBound Offroad as a possible solution as the coolant temp runs near normal (210) with the A/C off and the AUX fan switched on (via my bypass).at idle aux fan should not be needed all the time to be on .

[Mudderoy]

at idle aux fan should not be needed all the time to be on .

huh? Idle isn't a problem for me and the aux fan isn't needed at idle.

[freegdr]

has a manual gauge ever been installed and driven to compare readings

[Mudderoy]

has a manual gauge ever been installed and driven to compare readings

No, I did replace the temp sensor and it read higher. I hooked up a OBD II unit and recorded the temp via my laptop, and that's how I found out the gauge isn't reading what you think it is. I think the first hash mark past 210 is like 230.

You can smell and feel the additional heat as well. Keep in mind I bought this Jeep new, so I know it pretty well after 12+ years. This is why I don't like driving it on the highway for long periods of time because it loses power and smells hot. With the mods I have resolved most of the problems, and certainly have fixed the loss of power on hot days.

[freegdr]

what about air and exhaust mods have any been done if exhaust cant get out temps will be a little warmer from motor working harder to run bigger tires

[freegdr]

it would be like jogging while trying to breath thru a straw

[freegdr]

was ahigh flow thermostat also in stalled could be high flow pump is sucking so hard water cant get out of motor fast enough causing hose to suck shut

[freegdr]

hope you get it fixed

[Mudderoy]

was ahigh flow thermostat also in stalled could be high flow pump is sucking so hard water cant get out of motor fast enough causing hose to suck shut

Yes high flow thermostat and high flow thermostat housing.

[msmoorenburg]

Sorry Tony, I had that mat! I would still put the lower metal skid back on. It attaches to the same spot as the mat

[Mudderoy]

Sorry Tony, I had that mat! I would still put the lower metal skid back on. It attaches to the same spot as the mat

So don't do the mat, Matt?

[msmoorenburg]

So don't do the mat, Matt?

:rotfl2: don't tread on me :rotfl2: no real point the mat is only a inch longer than the skid.

[bluedragon436]

I took mine off to retrieve my radiator cap one day... haven't noticed any changes as far as temps go since I removed it.. but think I am going to put it back on, so that I will have that barrier from the water, mainly getting up into my alt. Going to upgrade it anyways, just not right this minute..

[oderdene]

Yes high flow thermostat and high flow thermostat housing.

did you tried flow restrictor, like this?

http://jeep-xj.info/Restrictor6.jpg

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

[gary63]

Have you tought about a eng. oil cooler to help cool the oil that will help cool the eng.

[Mudderoy]

did you tried flow restrictor, like this?

http://jeep-xj.info/Restrictor6.jpg

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

Yes, tried it. Caused all kind of problems.

[Mudderoy]

Have you tought about a eng. oil cooler to help cool the oil that will help cool the eng.

Yes I have thought about it, but not tried it yet. :thumbsup:

[LizardRunner]

Da lizard doesn't have either the skid or the rubber mat, came to me the way it is and I don't have any overheating issues to date. Tony you could try using a stiff piece of cardboard underneath to see if there is a difference. Your running hot issue is a real puzzler, considering you have done just about everything I can think of to try for a fix already. Perhaps you just need to get some aluminum sheet and form a shroud that goes from the radiator to behind the fans for the top section and another for the bottom that is the same or similar? On NASCAR cars they usually have a shroud that covers the whole fan all the way around and extends back about 4" beyond the fan blades towards the engine, with only cutouts for necessary clearances. These engines tend to run very hot at everything but race speeds. Again you could first use some cardboard to mock one up and give that a try before going to the aluminum.

[Mudderoy]

Da lizard doesn't have either the skid or the rubber mat, came to me the way it is and I don't have any overheating issues to date. Tony you could try using a stiff piece of cardboard underneath to see if there is a difference. Your running hot issue is a real puzzler, considering you have done just about everything I can think of to try for a fix already. Perhaps you just need to get some aluminum sheet and form a shroud that goes from the radiator to behind the fans for the top section and another for the bottom that is the same or similar? On NASCAR cars they usually have a shroud that covers the whole fan all the way around and extends back about 4" beyond the fan blades towards the engine, with only cutouts for necessary clearances. These engines tend to run very hot at everything but race speeds. Again you could first use some cardboard to mock one up and give that a try before going to the aluminum.

Yep it's been thought of and discussed, but a chance conversation made me think there might be a cheap and factory alternative to doing what you have suggested. Thanks for the post though.

[OrangeXJ]

Ahhh excellent. If someone has one :camera: I'd love to see what it looks like. I'm trying to resolve my running hot problem.

Just my 2 cents I have read most of your posts on running hot at freeway speeds. I don't remember if started after you put the lights on. Looking at the front of your jeep the lights have to block air flow. If you have not allready done so make a test drive with out the lights,

[Mudderoy]

Just my 2 cents I have read most of your posts on running hot at freeway speeds. I don't remember if started after you put the lights on. Looking at the front of your jeep the lights have to block air flow. If you have not allready done so make a test drive with out the lights,

It started after the lift, wheels and tires. Before all mods after those.

[oderdene]

Is it possible to test with closed hood scoop on both speed range? I am not pretty sure but maybe at high speed air sucks from bottom side of engine and vents away through hood scoop (like plane wing?). At lower speed air went through default way, grille-radiator-hood scoop/firewall.

[Mudderoy]

Is it possible to test with closed hood scoop on both speed range? I am not pretty sure but maybe at high speed air sucks from bottom side of engine and vents away through hood scoop (like plane wing?). At lower speed air went through default way, grille-radiator-hood scoop/firewall.

Everything I have done has either made no change or a slight improvement, so that means it had heat creep prior to the hood scoop. To answer your question yes it is possible to test it, but since the problem existed before and after the mod I think it would be a waste of time.

[oderdene]

Everything I have done has either made no change or a slight improvement, so that means it had heat creep prior to the hood scoop. To answer your question yes it is possible to test it, but since the problem existed before and after the mod I think it would be a waste of time.

yeah, I've seen red xj photo without hood scoop from another thread, just after posted here. it heated just after lift and big tire, last thing I suggest - test with small (standard) tire. maybe it looks odd, but helps problem isolation.

[gary63]

a nother trick to try is install a airdam or a lond mud flap across the back bumper like they use on motorhomes and semis . you can take it off if it dosn't work . it is used to help gas milage and brake up tha air flow under the auto .

[Mudderoy]

yeah, I've seen red xj photo without hood scoop from another thread, just after posted here. it heated just after lift and big tire, last thing I suggest - test with small (standard) tire. maybe it looks odd, but helps problem isolation.

Yep thought of that, but I don't have small tires or wheels to fit. Besides that wouldn't be a solution that I would accept. It would just confirm what I suspect that the air flow is going above and below the Jeep instead of through the radiator.

I think the solution is going to be creating either an air damn or increase the vacuum behind the radiator. Even thought fans would never equal the speed of 70 mph wind it can create a greater vacuum and perhaps direct more of that 70 mph air flowing through the radiator.

[oderdene]

Yep thought of that, but I don't have small tires or wheels to fit. Besides that wouldn't be a solution that I would accept. It would just confirm what I suspect that the air flow is going above and below the Jeep instead of through the radiator.

I think the solution is going to be creating either an air damn or increase the vacuum behind the radiator. Even thought fans would never equal the speed of 70 mph wind it can create a greater vacuum and perhaps direct more of that 70 mph air flowing through the radiator.

If I remember correct, some of us have a stocker. I am announcing following:

http://www.xjtalk.com/showthread.php?p=71920#post71920

[Mudderoy]

If I remember correct, some of us have a stocker. I am announcing following:

http://www.xjtalk.com/showthread.php?p=71920#post71920

The thought it great, but I see a couple problems. I don't have the original bumper on the XJ that included the factory air damn. I don't have the original gears, stock was 3.55 I now have 4.56.

What I need is a large wind tunnel capable of adjustable air speed from 0 to 80 mph and a device to measure the air flow through the radiator.

[oderdene]

we will do this experiment with stock tire only, as announced, if we didn't get good result, announce again our "next LAST experiment" with another stock part (for example stock front bumper with air dam etc) :D :D :D

[alwaysxj]

I'm trying to resolve my running hot problem.

Tony move to a colder climate.:smiley-laughing021:

mine runs cool all year round.:smiley-gen165:

[ralphy]

well my '99 runs around 200 degrees on the hiway and I haven't noticed the splashguard but I think it's there. With everything you've replaced on the cooling system I'm at a loss for ideas, if it's an airflow issue try taking the hood off and drive it. I know that sounds dumb but it may help pinpiont an airflow issue. hope it helps.

[Mudderoy]

well my '99 runs around 200 degrees on the hiway and I haven't noticed the splashguard but I think it's there. With everything you've replaced on the cooling system I'm at a loss for ideas, if it's an airflow issue try taking the hood off and drive it. I know that sounds dumb but it may help pinpiont an airflow issue. hope it helps.

Nope that's not the first time I've heard that, but unless I want to do that all the time (or maybe just on long trips) it really isn't worth the effort in my mind.

[LizardRunner]

Tony, do you have really good radiator cowling (shroud) in place? on da lizard I've been thinking of increasing the fan shroud depth through to the far end of the radiator. A deep shroud will get the air flowing through the radiator much better than the stock plastic shroud. If you take a look at NASCAR setups, you will see that they build the fan shroud to as deep as possible. They do this so the air flow is definately going through the radiator (creates a vortex effect) this just might work for you.

[Mudderoy]

Tony, do you have really good radiator cowling (shroud) in place? on da lizard I've been thinking of increasing the fan shroud depth through to the far end of the radiator. A deep shroud will get the air flowing through the radiator much better than the stock plastic shroud. If you take a look at NASCAR setups, you will see that they build the fan shroud to as deep as possible. They do this so the air flow is definately going through the radiator (creates a vortex effect) this just might work for you.

I never have cared for the factory fan shroud. It's minimal at best, but I think I did a search and I never found an aftermarket alternative. Never attempted to build one myself, but yes it crossed my mind.

[XJ4IV]

Mine had that rubber part on all three of my XJ's and I took them ALL off... they are there to prevent your engine from getting dirt and road debris on it... LOL

[LizardRunner]

Tony, try this page, you should find what you need there. You will probably need to do a little panel bending to get the one you pick to fit just right but this will most likely do the trick for your high heat problem. http://www.summitracing.com/search/Part-Type/Fan-Shrouds/?keyword=fan+shroud&kr=fan+shroud

[GFS01XJ]

My 01 has the shield underneath it. I know its mostly for prtoection. but agree that it could also help with airflow. It helps direct the air out the back of the engine compartment and helps keep and turbulence from forming. It wouldn't be the most expensive option you have tried?

[Mudderoy]

My 01 has the shield underneath it. I know its mostly for prtoection. but agree that it could also help with airflow. It helps direct the air out the back of the engine compartment and helps keep and turbulence from forming. It wouldn't be the most expensive option you have tried?

lol exactly! $$$

[Mudderoy]

Something I suspected some time ago and may have already mentioned may be at least part of the answer.

Saturday I had to get on the highway to drive over to the sticker place. It was about 30 miles round trip. After about 5 miles at 70 mph I noticed the temp hitting the 210 mark, should be just a tad under. I checked the weather service, and it said air temps were 80 degrees. Since I was running the A/C I expected the coolant temp to stay down but then remembered.

I had a problem with my A/C system some years ago where it lost it's coolant charge. I drove my Jeep for a good year without A/C. I did drive to recharge the system but it didn't hold. After a while I noticed there was a leak fix that you could put into the system, so I tried it, and I've had A/C since. I may have to recharge it every 3 or so years.

It seems like before I had the problem the A/C would come on and stay on, but now it cycles on and off more than what I would expect it to, but I really have to reference. So instead of having the efan on all the time, it's only on as long as the compressor is on.

So since I now have a efan bypass switch I reached up and turned it on. After a couple of miles the temp dropped to a hair below 210 and stayed there until I got off the highway. Then it dropped well below 210, but not as far as the hash mark. I turned the bypass off.

So if fans make NO difference at highway speeds then the fans must be doing something else to improve my air flow. I think it's creating lower air pressure on the other side of the radiator and causing more of the air to come through the radiator.

I do expect that as outside air temps get hotter the configuration that I have will not be able to keep up and in full blown summer I'll have problems with heat creep again.

I need to get a better vacuum behind the radiator, or a better air flow through the radiator.

[4.3LXJ]

It is too bad you live in Texas Tony. Ya'll could just get some belting and come by the shop and we could fix this up in an afternoon.

[4.3LXJ]

Something I suspected some time ago and may have already mentioned may be at least part of the answer.

Saturday I had to get on the highway to drive over to the sticker place. It was about 30 miles round trip. After about 5 miles at 70 mph I noticed the temp hitting the 210 mark, should be just a tad under. I checked the weather service, and it said air temps were 80 degrees. Since I was running the A/C I expected the coolant temp to stay down but then remembered.

I had a problem with my A/C system some years ago where it lost it's coolant charge. I drove my Jeep for a good year without A/C. I did drive to recharge the system but it didn't hold. After a while I noticed there was a leak fix that you could put into the system, so I tried it, and I've had A/C since. I may have to recharge it every 3 or so years.

It seems like before I had the problem the A/C would come on and stay on, but now it cycles on and off more than what I would expect it to, but I really have to reference. So instead of having the efan on all the time, it's only on as long as the compressor is on.

So since I now have a efan bypass switch I reached up and turned it on. After a couple of miles the temp dropped to a hair below 210 and stayed there until I got off the highway. Then it dropped well below 210, but not as far as the hash mark. I turned the bypass off.

So if fans make NO difference at highway speeds then the fans must be doing something else to improve my air flow. I think it's creating lower air pressure on the other side of the radiator and causing more of the air to come through the radiator.

I do expect that as outside air temps get hotter the configuration that I have will not be able to keep up and in full blown summer I'll have problems with heat creep again.

I need to get a better vacuum behind the radiator, or a better air flow through the radiator.

Tony, I have had the same experience with mine. The fans are necessary on XJs. I still think it is a basic design problem. But anyway, I have a Taurus fan sitting around and thinking of using it for a total of 6000 cfm. But I don't think I have enough alternator for that and heater fan and lights. Might need a alternator upgrade for that.

[default83]

i would install a mech. gauge and make sure all connections are good for the temp.

could your A/C be putting more strain on the engine due to going out? idk dude, sounds like bad readings to me.

do you lose any coolant?

[Mudderoy]

i would install a mech. gauge and make sure all connections are good for the temp.

could your A/C be putting more strain on the engine due to going out? idk dude, sounds like bad readings to me.

do you lose any coolant?

temp is correct, or correct enough, I'm confident.

I am leaning that way, it certainly didn't run as hot with the A/C off, way back when the problem first started.

Nope, no leaks, no over flow.

[4.3LXJ]

If an engine is prone to overheating and you operate the AC, you are preheating the air going into the radiator. That is where the system looses the heat it picks up from the inside.

[modestmar00xj]

yeah i was one of the first things i removed! the nasty rubber mat that was held on by one plastic snap! lol.

[hookedonxjs]

I take them off first thing evry time I get another xj. Don't know if it cools any better or not but did not notice any change in temperature. It's my own opinion it's to keep brush and weeds out due to it's low stock ground clearence. I look at it as something else to fall off.

[Mudderoy]

Yeah I just need to put the stock skid plate back on...

[XJ Rat]

Tony;
Just an idea I saw that might have potential for you.

Page 64 of the Nov 2010 issue of JP magazine, "A piece of rubber hung down in front of the front axle reduced the airflow under the Jeep, thus increasing air flow through the radiator and curing a persistant overheating problem".

Sure, the article is about a Willys wagon with a Ford V8, but the wagon was lifted, and by the artilce, the overheating problem was on the highway...same as yours.

Page 66 you can see a picture of what he did.

Just an idea....

[uberxj92]

Yep I've heard that before and that's why I went through all the other stuff instead of throwing fans at it to begin with, but read what I said.

It runs hot (not over heat) at 70 mph with A/C on. It runs a little cooler with the A/C off, but with A/C off and AUX fan in bypass (ON) it runs nearly normal.

So this means there is an air flow issue and it also means that the AUX fan is pulling MORE air through the radiator AT highway speeds. So it means the fans DO make a difference.

It could be that in my configuration what it does is the aux fan creates a vacuum behind the radiator and is causing more air to be directed through the radiator.

i noticed this same issue with all of my xj's, @ speed if the aux fan isn't on she gets warmer fast. i believe that the air flowing thru the rad at speeds above 40ish is restricted by the aux fan...the air has to turn the fan blades, if the fan is on then there is little to no resistance there. hence more air flow.
i also, have hood vents & a snorkel. they both helped emencily

[Mudderoy]

i noticed this same issue with all of my xj's, @ speed if the aux fan isn't on she gets warmer fast. i believe that the air flowing thru the rad at speeds above 40ish is restricted by the aux fan...the air has to turn the fan blades, if the fan is on then there is little to no resistance there. hence more air flow.
i also, have hood vents & a snorkel. they both helped emencily

Yeah I never thought about the electric fan being a block.

Interesting the snorkel would improve engine temps...

[tbone]

This is just a thought, you can run higher temps if your coolant passes through the rad too fast, could the highflow pump and thermostat at highway speeds be passing coolant through a little too fast. Just something to think about, hope you get figured out. :patriot:

[Mudderoy]

This is just a thought, you can run higher temps if your coolant passes through the rad too fast, could the highflow pump and thermostat at highway speeds be passing coolant through a little too fast. Just something to think about, hope you get figured out. :patriot:

Thanks, yep that's been mentioned before. The temp is actually better now as in the past I would hit that second hash mark and at times it would then leap to the hash at the beginning of the RED. So everything I have done HAS improved the situation, just not resolved it to my liking.

[KH96XJ]

Has anyone ever tried a pusher fan for this issue in the past?

[Mudderoy]

Has anyone ever tried a pusher fan for this issue in the past?

I've read that pushers are what only 70% as efficient as pullers? Still it would be good to know if someone has.

[KH96XJ]

I've read that pushers are what only 70% as efficient as pullers? Still it would be good to know if someone has.

Maybe in conjunction with a puller they might offset any pressure issues at speed?

[dagr8tim]

Somebody on NAXJA (I think) used a sheet of galvanized steel to make a replacement splash shield. I never really worried about it. My 97 didn't come with one, and my 98 had that and the factory skid plate. I figure the skid plate is good enough on it's own.

[Carves]

X 2 with all the previous comments about it just being a splash guard.

You blokes have the alternator mounted down low ... on the LHD, dont you ??

There is some likelyhood the mat would help slightly with creating a lower pressure behind the rad ...

Removing it from mine hasnt made any discernable difference tho ... Thats keeping in mind that I still have the factory bash plate ... and with only 2" of lift - Im not presenting a whole bunch of drivetrain and steering components into the airflow, to cause any buffetting effects/actions that might upset through flow at the rad.


If you're still pondering it Mudderoy - Theres a bit on airdams and stuff in these links.]

http://office.autospeed.com/cms/A_2159/article.html
http://office.autospeed.com/cms/A_2160/article.html
http://office.autospeed.com/cms/A_2162/article.html
.