Welcome to the next contribution to the
The Official Pirate4x4.com Jeep Talk Bible (http://www.pirate4x4.com/forum/showthread.php?t=705122)

Topic of the Month Engine Cooling

Show pics and discuss modifications you have done to upgrade your cooling system. Topics include: electric cooling fans, aftermarket rads, cooling additives, high flow water pumps, Thermostats. Cooling is a "system" so tell us your complete setup that works.

This does not include factory upgrades from closed cooling to open cooling systems.

Also see:
GriffinThermalProductsKingoftheHammersRadReview (http://www.pirate4x4.com/tech/billavista/Cooling/#GriffinThermalProductsKingoftheHammersRadReview)
The Pirate Cooling Bible (http://www.pirate4x4.com/tech/billavista/Cooling/)

I run a GDI 3 core with some Royal Purple "Purple Ice". Hasn't been cooling a damn thing in 2 years, but when I did I kept me around 170 street driving and a touch below 210 wheeling ALL day. Rig had a bone stock 4.0, and Im ran it HARD. Never had ANY issue's at all. Stat is 185.

No plans whatsoever for cooling upgrades with the new build.

Edit....Also run a 15" electric Flex-a-lite. Nothing fancy, just a replacement for when the stocker was eaten alive.

This is more of an upgrade for the Renix guys. I am running a mostly stock cooling system except for the cooling cap on the pressure bottle. I read about alot of people talking about how the closed cooling system sucks and that it should be upgraded to make it work. Well that can work, but I am with the small group of us that understands that a properly maintained closed cooling system can work.

I had a prolbem with the cap on my stock bottle leaking, but hey it was 20+ years old at the time and the previous owner didn't take good care of the Jeep. I purchased a cheap ol' bottle and cap off of ebay and it lasted about 2 months before the cap blew off. So, I puckered up and went to the dealership for a bottle and cap and it lasted about a year before the cap started to leak. I got to looking at it and it was the same cap as the cheap china bottle off of ebay.

I thought there has to be a cap out there that works like the origional cap (the origional cap was more robust looking). I did some searching and found some real old posts about a Volvo coolant cap. I went to the Volvo dealership and purchased the cap. I think it was about $45, and it is still working today and my temps stay around 200* and the coolant level in the bottle stays constant with no signs of leaks.

In my research, most people were using the Volvo bottle also, but the threads on the cap are the same as the XJ bottle. I used the stock bottle since it fits better.

**edit** I forgot to mention, I had to replace my radiator due to a couple rows missing. I replaced it with a CSF 3 row radiator.

http://i22.photobucket.com/albums/b346/TMXONR/Volvo%20Coolant%20Bottle%20and%20Cap/DSC06007.jpg
http://i22.photobucket.com/albums/b346/TMXONR/Volvo%20Coolant%20Bottle%20and%20Cap/DSC06008.jpg
http://i22.photobucket.com/albums/b346/TMXONR/Volvo%20Coolant%20Bottle%20and%20Cap/DSC06009.jpg
http://i22.photobucket.com/albums/b346/TMXONR/Volvo%20Coolant%20Bottle%20and%20Cap/DSC06012.jpg

Factory 89 Comanche 4.0 ... it couldn't even look at a hill without overheating.

swapped in a GDI 3-core, kept it closed cooling, and used a 180* t-stat. Never went over 200-205* once I got the air out of the system.

4.6l stroker in mine, with stock thermostat.

I run the CSF 'heavy duty 3-core' radiator; got mine from www.radiatorbarn.com. I've got two of the stock electric fans. The one on the passenger side replaces the mechanical fan and is on 100% when the key is on; the driver side is hooked up to the factory harness and comes on via the temp sensor and ECU.

I gotta be sitting still with my foot to the floor trying to get up something to get the second fan to kick in...if I keep trying, it gets up to maybe 230ish. As long as the truck is moving the second fan rarely kicks on.

I may upgrade to something more substantial, but I had the fans sitting around and the packaging works out nicely. If I find the limits of it I'll post back.

4.7 stroker, 1 tons, 37s, Texas 100*+ heat, GDI 3 core radiator open style system, stock thermostat, never gets to 200* Drove to Moab and back and all over Texas. Just flat worked and I was happy. Until I got a hole in the radiator, put in a stock replacement and now its at 230* all the time.

My buddy has an XJ he converted from closed loop to open loop. It's a junkyard radiator pushed forward a few inches so he could squeeze a taurus fan between it and the engine. The damn radiator is so wide he was able to fit the taurus and the stock efan. It's a pretty fresh setup, but we did a gauntlet run 4th of july weekend leaving from Sacramento, hitting up Slickrock, Deer Valley, Strawberry Pass and the Rubicon from wentworth to soupbowl and back out to home. We did about 350+ road miles with some WICKED extended grades in mid-80* weather and 40+ trail miles on the setup that weekend without ever creeping up on him.

It's got an AW4 that is bypassing the radiator for a big cooler, 5.38 gears and 35" TSL's for reference.

M
It's got an AW4 that is bypassing the radiator for a big cooler
That makes a big difference and not running the AC helps.
A winch blocking the grill can make a difference.

Yeah I definately agree, he just needs to get a gauge on the tranny ASAP. Right now we have no idea how hot the tranny's running, but he said the tunnel got pretty hot on a few grades, so we need to know what's goin on.

I've got a CSF 3 core radiator and the temp is usually around 210 no matter what. I've got a winch and solenoid pack covering a bit of it (winch sunk into the bumper and grille) but it didn't really affect the temp at all.

Thought about bypassing the trans cooler in the radiator to keep everything cooler in the summer, but I figured it would be good for it since it's pretty damn cold here in the winter. My trans temp gauge hardly ever goes about 120 unless I'm wheeling or its over 80 degrees out and I'm on the highway/in traffic.

I've already got another electric fan to wire up in place of the engine driven fan. Probably wire it up to run all the time with a switch in the cab just in case I need to turn it off for water or whatever.

i just ran the stock cherokee 3 core radiator and wired my stock electric fan to a switch. when wheeling i would normally just leave the fan on all the time. sometimes id turn it off and it would typically stay cool even with it off but i left it on most the time just for insurance...maybe throw some water wetter or something in it if you want too.

89 XJ:

Hesco water pump - got tired of changing out Napa specials every 4-6 months. Lasted 6 years and still going.

Modine 2 (5/8") core radiator
Dual 13" Delrae Electric Fans (4000 cfm)

Cools great till I poke a hole in the radiator. Replaced with a knock off Modine unit as Modine was bought out and they no longer make the large 2 core just the crappy 3 core style. Wasn't overaly happy with the knock off quality wise but it seems to be doing the job.

I looked at running the Griffen unit but with it being and 1" or so thicker it wouldn't fit in the front of the jeep. Otherwise I would have gone with it no question. :(

Stock 4.0 with CSF 3 row all metal, radiatorbarn $178 shipped. Stock mechanical fan and late model xj 10 blade electric. the Electric has never turned on and the temp topped at 190 (mid 90s weather) last time I went wheeling. I need to replace my thermostat though because I'm pretty sure it is stuck open.

Before I got rid of my old '89 I pulled the GDI 3-core shuffle and replaced every piece of hose, along with the newer valve and a fresh thermostat and it worked wonders.

Lets also hear about hood vents and auxilary fan setups; I was planning to do hood vents but never got around to it.

I had a pair of Lebaron hood vents on my 91 and every time it rained, my TPS screwed up and the jeep wouldn't run. I wouldn't do that again without some sort of splash guard or drip tray over the TPS.

putting a cooler thermostat in isn't the fix all for cooling issues..

4.0's are not small block chevy's, they have a computer, a computer that wants the engine to run at *192 degrees, and will run full rich until it gets there, which means.. dick ass mileage..

I've got RunCool hood vents and I'm pretty sure they don't make much of a difference. Might keep the underhood temps down a tad, but they definitely don't make the engine run any cooler.

Also, I've never had a single problem with water getting into the engine bay through the vents and screwing with any electrical stuff. I've been in downpours, 2 feet of snow and have sprayed water in the vents while washing the Jeep. No issues and the vents are placed right over the injectors on one side and the spark plugs/cap on the other.

Quick question - how are we measuring our engine temps? Stock gauges? I guess that would beg the next question - how reliable are the stock temp gauges?

I have a completely stock 2000 XJ that I run a CSF 3 row all metal radiator in. Everything else is stock. Cools fine, but the one problem is the overflow bottle. Our family does a lot of geocaching and back country exploring which is very dusty. The dust easily gets in the overflow bottle and contaminates the coolant. I finally plugged the hole in the bottle and put a small vent (a mister nozzle) in the cap.

I am with the small group of us that understands that a properly maintained closed cooling system is more efficient.


Fixed

wired my stock electric fan to a switch. when wheeling i would normally just leave the fan on all the time. sometimes id turn it off and it would typically stay cool even with it off but i left it on most the time just for insurance

I have the stock fan with a switch to the relay to turn on.


Lets also hear about hood vents and auxilary fan setups; I was planning to do hood vents but never got around to it.

I had a pair of Lebaron hood vents on my 91 and every time it rained, my TPS screwed up and the jeep wouldn't run. I wouldn't do that again without some sort of splash guard or drip tray over the TPS.

I jsut drilled holes in my hood and I had the same problem with the TPS. I just got a new hood for $25 and put it on.

My setup is stock except for a high flow 2 core rad that I got from 1800radiators.com.

New versus stock.

http://i85.photobucket.com/albums/k51/hadfield4wd/My%20Jeep/Radiators.jpg

Also as stated it needs properly maintained. I had a bunch of overheating. But mine had 235k on it all original parts. So I replaced the pressure bottle as it was leaking. Then the leakes went to the weakest part. Ended replacing hoses next. My fan clutch was no good so I replaced it as well. Finally the rad with the all metal 2 core high flow one.

http://i85.photobucket.com/albums/k51/hadfield4wd/hood1.jpg

I had some magnetic signs to cover the holes but it still leaked enough to damage a tps.

http://i85.photobucket.com/albums/k51/hadfield4wd/hood4.jpg

IMO this is stupid. I did it before I fixed all my other stuff. After I got it cooling, couldn't get the engine to stay hot. I went back to a regular hood. It still runs cold 160* if i coast downhill. If I wheel in the winter I have to block the rad.

The only time it heats up is when you are sitting still and its 100 deg out I kick on the manual switch and it stays where it needs to.

Again maintenance is the key.

putting a cooler thermostat in isn't the fix all for cooling issues..

4.0's are not small block chevy's, they have a computer, a computer that wants the engine to run at *192 degrees, and will run full rich until it gets there, which means.. dick ass mileage..

I get dick ass mileage. On a '91 would you happen to know which sensor sends the temp reading to the ecm. Is it the one on the head or the one in the thermostat housing? Because if its the one on the head, mines missing witch would explain my excessive fuel consumption.

I get dick ass mileage. On a '91 would you happen to know which sensor sends the temp reading to the ecm. Is it the one on the head or the one in the thermostat housing? Because if its the one on the head, mines missing witch would explain my excessive fuel consumption.

On a 91 the thermostat housing is the temp sensor (data to computer), and the on in the driver side back of the head is the temp sender (info to tempt gauge)

Has anyone run a rear mounted radiator on a Renix 4.0. I'm thinking of moving mine back there this winter when I chop my MJ. I'm pretty sure I'd have to convert to an open type system?

Quick question - how are we measuring our engine temps? Stock gauges? I guess that would beg the next question - how reliable are the stock temp gauges?




I have two gauges. One is the GM style in the newer style t-stat housing, this one I read with the laptop (painless system). The second is a Steward and Wagner gauge I just installed so I can visually monitor the temperature. Sensor I tapped into the flat spot on the front of the t-stat housing. The stock gauge before I did the whole ripping out of wires and old engine was pretty accurate according to by laser temp guns.

They read very close or as close as I can tell but they are both in the same location. Runs right at 205-210.

Cutting holes in the hood never made any sense to me. Other then reducing under hood temps a bit, engine will still run at 210.

Has anyone run a rear mounted radiator on a Renix 4.0. I'm thinking of moving mine back there this winter when I chop my MJ. I'm pretty sure I'd have to convert to an open type system?

Either would work. Just make the radiator cap fill on an open system the highest point so you can bleed the air out of the system. If you relocate the closed system move the bottle with it and make it the highest point. Id do a closed system with an aftermarket radiator, I wouldn't want an ugly bottle above the radiator, but it would look better then an ugly muffler above the radiator...:flipoff2:

This is a ron davis, way overkill, dual pass so inlet and outlet are on the same side.
packaged nicely.
http://wheelingarizona.com/forums/download/file.php?id=10377&t=1

Don't overlook the value of an oil cooler. I am planning on installing an oil filter relocation kit on my '88 MJ to get rid of the upside down filter. I will plumb a cooler then.

If you don't have a thermostatic adapter, you may need to bypass the cooler in the winter to get it up to temp & out of "rich" mode....

I went to the Volvo dealership and purchased the cap.

Volvos are plentiful over here and i have a shitty ass leaking cap..
Did you find any specific Volvo-model to get that cap from?

Volvos are plentiful over here and i have a shitty ass leaking cap..
Did you find any specific Volvo-model to get that cap from?

I am pretty sure that it is from a 940 turbo. It has to be the turbo because apparently they had the higher pressure rating. Just look for the green cap with the number that matches the one in the pic. If you see a black one it may have a lower pressure rating. I bought a cap at a black cap at a JY to test things out and then went to the Volvo dealership to get a new one that was the correct number.

Thanks TMXONR :smokin:

I have had issues with cooling, my aux fan never worked right so I wired it to a switch and if it starts to get warm I turn it one and it seems to help. I am looking to do a 3 core radiator, water pump, and all new hoses soon.

I did buy the GenRight hood vents, my engine temps are not any cooler while sitting but as soon as I start to move they drop a lot faster then before the vents.

There a bit much but they seem to help a little, since I installed the vents I have not gotten it over 220.

http://i588.photobucket.com/albums/ss323/jrw7072009/Jeep%20stuff/Picture001-2.jpg

http://i588.photobucket.com/albums/ss323/jrw7072009/Jeep%20stuff/Picture002-2.jpg

I'm also running the Volvo cap on my renix, as well as two tiny (1/16") holes in my thermostat, one at 12 o'clock and one at 6 o'clock, so the system self burps. Before I replaced the cap, I tried the t-stat trick first, worked great until my cap failed. Now with the cap I can't get the damn thing to overheat.

I was smashing on her at the last Barstow race in 109* weather, and she wouldn't come over 180... I think I need smaller holes in the t-stat as well.

However, I got my cap from autozone for about 12 bucks. It's for a late 80's Volvo 740 with a 2.3.

http://www.swedishautoparts.com/shop/catimages/Volvo-Expansion-Tank-Cap-9445462.jpg

Volvos are plentiful over here and i have a shitty ass leaking cap..
Did you find any specific Volvo-model to get that cap from?

I am pretty sure that it is from a 940 turbo. It has to be the turbo because apparently they had the higher pressure rating. Just look for the green cap with the number that matches the one in the pic. If you see a black one it may have a lower pressure rating. I bought a cap at a black cap at a JY to test things out and then went to the Volvo dealership to get a new one that was the correct number.



Mine is black, for a 740 w/ a 2.3. It's got a 16lb. pressure rating.

I personly beleive the best cooling mod you can do is increase the volume of coolant, I thought about it for years and kept trying to think of ways to put inline tanks into the hoses to increase the volume but never got around to playing with it. Once I moved the rad to the back when I buggied it, I added about 5 gallons of volume to my system with the rad lines running from the front to the rear, now I can run it all day long without it getting over 110, think of it this way, 1 cup of water starts to boil right away but it takes alot longer to get a galon to boil

Richard is that suppose to say 210 or 110? Serious question too not being a dick...

110

Mine is black, for a 740 w/ a 2.3. It's got a 16lb. pressure rating.

I'm guessing, based on previous Volvo-experience, that pretty much any Volvo-cap will fit. They have been known to use interchangeable parts throughout the years/models. Kinda like GM..

110

Richard, that sounds awfully low. I know the 4.0 likes to operate within a certain range (something like 180-210*)...110 sounds like it would do some harm to the motor.

What is it gonna hurt when you only run 10 minutes at a time competeing, hell they never get up to temp in that short a period anyways

What is it gonna hurt when you only run 10 minutes at a time competeing, hell they never get up to temp in that short a period anyways

You make a good point :D

My mind was thinking more long trail run...

I do day runs in it but I do not think it really matters as the temp effects more of the emissions running side of things a road speeds vs trail running at slow speads, in other words, I don't think it really ever gets into the RPM range to make a difference

I do day runs in it but I do not think it really matters as the temp effects more of the emissions running side of things a road speeds vs trail running at slow speads, in other words, I don't think it really ever gets into the RPM range to make a difference

quick on topic questions;

what did you use, are you using, for plumbing to get the coolant to the rad in the back?
is stock water pump adequate? or e-pump added?

I have flex hose at each end to make the connections and exhaust pipe on the underside going from front to back, so far a stock pump has worked just fine

we used 1.5in 120 HREW because it workes in a normal bender. Couplings are rubber and shielded so if one leaks it wont burn the occupants. Used radiator hoses at the radiator.