You would not notice a difference there. You would notice a difference on the highway.
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New cooling system overheating on the highway
- Thread starter HWK9USA
- Start date
You would not notice a difference there. You would notice a difference on the highway.
scottmcneal
NAXJA Forum User
- Location
- not here
Did it get hot before or after you installed these?
The original radiator was was due for replacement. Many collapsed fins, corrosion, etc so I opted to replace. Considering I was going to be relocating to a much hotter area I went with the Flexalite with the three e-fans.
We found out living in the low desert( plam springs CA) we couldn't run the three e-fans when it got hot out here. Would run cool if you was sitting in a drive thru for food and around town, then hit the freeway or a grade it would over heat.
I had him buy a stock rad from the dealer, The towing model. Has never over heated after that.
HTH
The original radiator was was due for replacement. Many collapsed fins, corrosion, etc so I opted to replace. Considering I was going to be relocating to a much hotter area I went with the Flexalite with the three e-fans.
We found out living in the low desert( plam springs CA) we couldn't run the three e-fans when it got hot out here. Would run cool if you was sitting in a drive thru for food and around town, then hit the freeway or a grade it would over heat.
I had him buy a stock rad from the dealer, The towing model. Has never over heated after that.
HTH
RedHeep
NAXJA #1499
- Location
- Landenberg, PA
I did this exact dance with my XJ. Idled at 195, ran at 235 at 60 mph. Everything in the cooling system replaced, some components twice. Played with the ZJ fan clutch, pulled weatherstripping, hood louvers, all that jazz. I did the 180 thermostat, watched the temps drop with the aux fan on in the driveway, right back to overheating on the highway.
Put in a Mopar HD radiator and fixed it. Runs at 198 at 60 mph with the a/c on when it's 95 degrees outside. Pulled up the mountain in 4 low in harlan in july at 25 mph for 15 minutes and barely hit 215. I spent two years convinced that it couldn't be the radiator because I'd just bought one and we all like to think that what we bought was the best.
If you "think" and don't "know" what your radiator is, you've probably got a radiator problem. Your engine makes heat when it's pushing the jeep around. The thermostat keeps the temperature at 195 at idle because that's what it's designed to do, it doesn't mean that your cooling system is capable of cooling the engine when it gets hot from working. If your cooling system was up to snuff, you would see 180 on the gauge because that's where the thermostat closes. If not, you need more radiator.
Put in a Mopar HD radiator and fixed it. Runs at 198 at 60 mph with the a/c on when it's 95 degrees outside. Pulled up the mountain in 4 low in harlan in july at 25 mph for 15 minutes and barely hit 215. I spent two years convinced that it couldn't be the radiator because I'd just bought one and we all like to think that what we bought was the best.
If you "think" and don't "know" what your radiator is, you've probably got a radiator problem. Your engine makes heat when it's pushing the jeep around. The thermostat keeps the temperature at 195 at idle because that's what it's designed to do, it doesn't mean that your cooling system is capable of cooling the engine when it gets hot from working. If your cooling system was up to snuff, you would see 180 on the gauge because that's where the thermostat closes. If not, you need more radiator.
You all make a lot of sense.
I have considered replacing the radiator. I thought this Flexalite top end radiator would at least come close to matching the hype.
I was on the east coast prior to coming off of active duty. I had this jeep in the shop getting the radiator swapped while I was bouncing around. They were supposed to save the old parts for me. Things got hectic and I had to have the jeep shipped to me and when it arrived the old stuff wasnt there. I will need to replace everything. The radiator, shroud, fan, clutch, etc. It would be nice if it was simply reinstalling the mechanical stuff.
I really didnt think I would end up here. I figured at worst I simply wouldnt see a gain in cooling. Not that it was terrible before but I figured a $1,000 setup would have some advantages.
THank you all for the insight
I have considered replacing the radiator. I thought this Flexalite top end radiator would at least come close to matching the hype.
I was on the east coast prior to coming off of active duty. I had this jeep in the shop getting the radiator swapped while I was bouncing around. They were supposed to save the old parts for me. Things got hectic and I had to have the jeep shipped to me and when it arrived the old stuff wasnt there. I will need to replace everything. The radiator, shroud, fan, clutch, etc. It would be nice if it was simply reinstalling the mechanical stuff.
I really didnt think I would end up here. I figured at worst I simply wouldnt see a gain in cooling. Not that it was terrible before but I figured a $1,000 setup would have some advantages.
THank you all for the insight
Brent T
NAXJA Forum User
- Location
- Glendale, AZ
Phoenix, AZ, 115 degree temps. Old radiator finally split after 17 years. New STOCK radiator, new water pump, new 195 degree Stant Super-Stat. Runs right at 200 - 205 per the factory temp gauge. Steady as a rock. On highway, off highway, uphill, downhill, it runs the same temp in all situations and that's in 100 degree plus ambient temps here in AZ. This is on 35's with 4.56 gears, AW-4 trans. I'm a firm believer in the stock radiator after reading all the horror stories people have had with the aftermarket.
Talyn
NAXJA Forum User
- Location
- Radford, Communistwealth of Virginia
Is your old water pump still serviceable?
I had a similar problem years ago. New CSF radiator, high flow t-stat housing, high flow water pump, high flow t-stat, and new hoses(with spring). It consistently over heated on the highway. I replaced the t-stat, tried a few other things. Finally replace the high flow water pump with a stock one. Cooling system worked better than ever after that.
I had a similar problem years ago. New CSF radiator, high flow t-stat housing, high flow water pump, high flow t-stat, and new hoses(with spring). It consistently over heated on the highway. I replaced the t-stat, tried a few other things. Finally replace the high flow water pump with a stock one. Cooling system worked better than ever after that.
It seems like each time I take it out it performs a little bit better.
I do still have the stock water pump and t-stat housing.
A friend is telling me he thinks I still have too much air in the system. I burped it with the left front elevated about 12-18 inches. Maybe I can take it out and find a couple rocks to crawl around on and try to get any air pockets to move towards the top.
I have read of a few people with strokers that have the same cooling set up as I do and dont seem to have problems. At least none that they are writing about or admitting too.
I do still have the stock water pump and t-stat housing.
A friend is telling me he thinks I still have too much air in the system. I burped it with the left front elevated about 12-18 inches. Maybe I can take it out and find a couple rocks to crawl around on and try to get any air pockets to move towards the top.
I have read of a few people with strokers that have the same cooling set up as I do and dont seem to have problems. At least none that they are writing about or admitting too.
Your first post you said you had a Hesco pump. Which one is installed right now?
WAZZUXJ
SoCal_XJ FB
- Location
- Aurora, CO
Start back at the beginning with a simple flush of the system.
I went through the same process a few months ago. It would only overheat on the freeway after going thru the system several times and replacing everything but what I thought was a good radiator. I finally replaced radiator with a new stock replacement and never went over 210 for a couple months. Then the overheating on the freeway returned.
I checked the fluid and chocolate milk brown. Flushed it several times with flush treatment and just water until the fluid finally drained out clean. After about 4 flushes, no problems since.
I flushed, filled, drove for 50-100 miles, flush. Repeat x 4 or until clear water drained out.
I went through the same process a few months ago. It would only overheat on the freeway after going thru the system several times and replacing everything but what I thought was a good radiator. I finally replaced radiator with a new stock replacement and never went over 210 for a couple months. Then the overheating on the freeway returned.
I checked the fluid and chocolate milk brown. Flushed it several times with flush treatment and just water until the fluid finally drained out clean. After about 4 flushes, no problems since.
I flushed, filled, drove for 50-100 miles, flush. Repeat x 4 or until clear water drained out.
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devildog0
NAXJA Forum User
- Location
- Hunt County Texas
I honestly still think that flexalite rad is causing your problems. More rows isn't always better on the XJ.
I didnt have a chance to take it out today like I wanted. I wanted to get it up on some steep inclines maybe rocks or something, and try to see if I could work some air out of the system.
I have flushed and flushed over the last few weeks. I took out the t stat, hooked a hose to the top heater line with a T and let it run for a long time. In excess of an hour. I would start the motor every little while to create some turbulence.
I need to do it again because I am getting some sediment up around the filler neck of the radiator. The horizontal tube below the rad cap. It looks a lot like black sand. I've scooped out a bunch, about a teaspoon full, and placed it in a paper bowl. Once it dries its like dust almost. Next time I pull some out Im going to use a magnet and see if it's metal... iron anyways. Maybe oxidized aluminum, or maybe even particles from a hose.
DevilDog, you maybe correct. I may end up pulling out the efans and go back to mechanical and see how it does. If that works so be it. If not then I will swap rads to an OEM for towing. It really burns my arse to think I spent this $1k on this "top o the line" cooling system with this result. I would also hate to pull it all only to find out the fix is something simple.
THis really shouldn't be so difficult!
I have flushed and flushed over the last few weeks. I took out the t stat, hooked a hose to the top heater line with a T and let it run for a long time. In excess of an hour. I would start the motor every little while to create some turbulence.
I need to do it again because I am getting some sediment up around the filler neck of the radiator. The horizontal tube below the rad cap. It looks a lot like black sand. I've scooped out a bunch, about a teaspoon full, and placed it in a paper bowl. Once it dries its like dust almost. Next time I pull some out Im going to use a magnet and see if it's metal... iron anyways. Maybe oxidized aluminum, or maybe even particles from a hose.
DevilDog, you maybe correct. I may end up pulling out the efans and go back to mechanical and see how it does. If that works so be it. If not then I will swap rads to an OEM for towing. It really burns my arse to think I spent this $1k on this "top o the line" cooling system with this result. I would also hate to pull it all only to find out the fix is something simple.
THis really shouldn't be so difficult!
Ronbo
NAXJA Forum User
- Location
- San Marcos, CA
I've wondered at what point the radiator hugging fans and shrouds become an impediment to airflow - maybe you found that point.
Although I did have a similar problem with a bone stock 96 and it turned out to be the water pump. It was the last thing I suspected, but it was probably a cheapo pump.
devildog0
NAXJA Forum User
- Location
- Hunt County Texas
That does suck. But when you google XJ overheating problems and read though hundreds of threads about the subject time and time again people throw aftermarket fixes at their overheating problem (I'm guilty of this as well) and time and time again when they get fed up and revert back to an all stock system it works again. This is barring some major mechanical issue such as a head gasket leak or something like that.
WAZZUXJ
SoCal_XJ FB
- Location
- Aurora, CO
Here is the "Super Flush" process I followed.
https://youtu.be/s--5ft5YiHg
I completely agree the stock cooling system is more than adaquate for the XJ. The only upgrades I have made to my system are a high flow water pump and the triple fan kit. Both upgrades are to improve slow crawling cooling efficency.
When a cooling system overheats only on the freeway, the problem is not an issue with air flow, it is an issue of heat dissipation usually caused by blockage in the radiator.
At idle the water is moving slow through the radiator allowing the water to dissipate heat before re-entering the motor, even with little air circulation. Speed up the water flow, even with increased air flow, but if the water is not circulating through the entire radiator it is not able to dissipate enough heat and the temp begins to climb.
I thought I had flushed my system thoughly as well, until I decided to follow the above process. I couldn't believe how contaminated my cooling system was, now I still monitor it. If it begins to look murky, I flush it again.
https://youtu.be/s--5ft5YiHg
I completely agree the stock cooling system is more than adaquate for the XJ. The only upgrades I have made to my system are a high flow water pump and the triple fan kit. Both upgrades are to improve slow crawling cooling efficency.
When a cooling system overheats only on the freeway, the problem is not an issue with air flow, it is an issue of heat dissipation usually caused by blockage in the radiator.
At idle the water is moving slow through the radiator allowing the water to dissipate heat before re-entering the motor, even with little air circulation. Speed up the water flow, even with increased air flow, but if the water is not circulating through the entire radiator it is not able to dissipate enough heat and the temp begins to climb.
I thought I had flushed my system thoughly as well, until I decided to follow the above process. I couldn't believe how contaminated my cooling system was, now I still monitor it. If it begins to look murky, I flush it again.
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WAZZUXJ
SoCal_XJ FB
- Location
- Aurora, CO
Here is a little added background of what I went though with my cooling system. I had the same overheating only on the freeway issue for almost a year.
Upon purchase of the Jeep I upgraded to the high flow water pump only because I though the original was toast as I had constant squeeling. No cooling issues. I realized later it was just a cheap belt.
About a year later I added the triple fan kit and some Napier hood vents. Still no overheating issues.
About a year after that I started having overheating issues on freeway. I began continuely trying to burp system. Temp would quickly drop and hold at 210 at idle, but quickly climb at 55+ mph for more than 5 minutes.
Short tips to work or around town, no problems. Any freeway driving or hills and temp would quickly climb. I fought with this for over 6 months. Thowing new hoses, t-stat, burping techniques, filling system though upper hose, etc. Nothing worked.
I finally replaced the radiator, only thing I had not replaced. That weekend I wheeled at Tierra Del Sol, Southern California desert with temps in the 90's. Jeep never broke over 210 all weekend.
About two months later, the over heating began again. Only at freeway speeds again. Now I was stumped as I had replaced everything. After playing the "burping" game for a few more weeks, I figured it must be the cylinder head. I had the head rebuilt and replaced the head gasket. Everything back together and first freeway drive, it overheats again!
This is when I started back at the basics and did the Super Flush. It took several flushes to clean it out, but after each flush, the temp would climb a little slower on the freeway. Once the system started flushing out clear, temp never climbs past 210.
Moral of the story, start with the simple stuff before throwing a ton of money and time into swapping parts.
Edit: Oh yeah, I also completely rinsed out the overflow bottle which was caked with crud on the bottom. Probably the most crucial part of the Super Flush.
Upon purchase of the Jeep I upgraded to the high flow water pump only because I though the original was toast as I had constant squeeling. No cooling issues. I realized later it was just a cheap belt.
About a year later I added the triple fan kit and some Napier hood vents. Still no overheating issues.
About a year after that I started having overheating issues on freeway. I began continuely trying to burp system. Temp would quickly drop and hold at 210 at idle, but quickly climb at 55+ mph for more than 5 minutes.
Short tips to work or around town, no problems. Any freeway driving or hills and temp would quickly climb. I fought with this for over 6 months. Thowing new hoses, t-stat, burping techniques, filling system though upper hose, etc. Nothing worked.
I finally replaced the radiator, only thing I had not replaced. That weekend I wheeled at Tierra Del Sol, Southern California desert with temps in the 90's. Jeep never broke over 210 all weekend.
About two months later, the over heating began again. Only at freeway speeds again. Now I was stumped as I had replaced everything. After playing the "burping" game for a few more weeks, I figured it must be the cylinder head. I had the head rebuilt and replaced the head gasket. Everything back together and first freeway drive, it overheats again!
This is when I started back at the basics and did the Super Flush. It took several flushes to clean it out, but after each flush, the temp would climb a little slower on the freeway. Once the system started flushing out clear, temp never climbs past 210.
Moral of the story, start with the simple stuff before throwing a ton of money and time into swapping parts.
Edit: Oh yeah, I also completely rinsed out the overflow bottle which was caked with crud on the bottom. Probably the most crucial part of the Super Flush.
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ingenio
NAXJA Forum User
- Location
- Juarez Chih MX
Dude,
few years ago it was time to replace my old stock radiator & installed an Aluminum 3row radiator, and bling-bling 3 e-fan system that worked OK for a while... too expensive (efans, temp control units, custom shroud,etc,etc,etc)
Due to the radiator dimensions, and the space from the engine to the rad we are limited to run low profile small diameter efans. Spal fans are among the higher performers for these type of devices, and inclusive the spal fans are not capable to provide the required CFMs to keep our XJs in the normal temp ranges, the OEM fan clutch & e-fan (96+) moves more air than any 3 efan setup you can find.
my junk is a 99 w/4.11/AW4/265/75/16 tires....after installing the new stock components (clutch fan and e-fan) never had issues again with temps ...A/C on in city traffic/highway driving or in the sand/dunes...
Hope you solve this issue shortly.
PS..Later I replaced the Aluminum radiator due to electrolysis problems/leaks..it had a ton of ground straps installed...went back to old timer all metal radiator.
The aluminum dissipates heat faster, but has a short service life.
few years ago it was time to replace my old stock radiator & installed an Aluminum 3row radiator, and bling-bling 3 e-fan system that worked OK for a while... too expensive (efans, temp control units, custom shroud,etc,etc,etc)
Due to the radiator dimensions, and the space from the engine to the rad we are limited to run low profile small diameter efans. Spal fans are among the higher performers for these type of devices, and inclusive the spal fans are not capable to provide the required CFMs to keep our XJs in the normal temp ranges, the OEM fan clutch & e-fan (96+) moves more air than any 3 efan setup you can find.
my junk is a 99 w/4.11/AW4/265/75/16 tires....after installing the new stock components (clutch fan and e-fan) never had issues again with temps ...A/C on in city traffic/highway driving or in the sand/dunes...
Hope you solve this issue shortly.
PS..Later I replaced the Aluminum radiator due to electrolysis problems/leaks..it had a ton of ground straps installed...went back to old timer all metal radiator.
The aluminum dissipates heat faster, but has a short service life.
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I just went through this on my truck-- granted, it's a chevy 350. same issue. Ran great sitting still, on the highway temps started to run away. Assuming the motor isn't running lean,
1) t-stat stuck? Try removing it to be sure .. it'll run fine in the summer without it
2) fans turning on at the right temp? (if you're using e-fans) clutch working ok on fans (if you're using mechanical fans)
3) water pump leaking?
4)) anything obstructing the rad?
I'm assuming since you didn't have overheating problems to begin with, and you've checked the usual suspects, your rad may be the cause. I went through every possible nut, bolt, clamp, and hose in my cooling setup before I finally admitted that brand new, $800 rad I had was causing the problem -- I was lucky, the manufacturer stood behind the product and rebuilt the shroud for me, and I now have no problems.
I agree with previous posts-- just try a normal stock rad, see if that works.
1) t-stat stuck? Try removing it to be sure .. it'll run fine in the summer without it
2) fans turning on at the right temp? (if you're using e-fans) clutch working ok on fans (if you're using mechanical fans)
3) water pump leaking?
4)) anything obstructing the rad?
I'm assuming since you didn't have overheating problems to begin with, and you've checked the usual suspects, your rad may be the cause. I went through every possible nut, bolt, clamp, and hose in my cooling setup before I finally admitted that brand new, $800 rad I had was causing the problem -- I was lucky, the manufacturer stood behind the product and rebuilt the shroud for me, and I now have no problems.
I agree with previous posts-- just try a normal stock rad, see if that works.
I'm running 3 spal fans w/ novak al. rad, in an '88 Cherokee with a chevy 350, and doesn't break 190. e-fans are fine, if the setup is designed properly. And just looking at CFM rating is misleading -- since they sit much closer to the rad than a menchanical fan, they *can* be lower cfm and still provide the same level of cooling. The old days of e-fans suck and mechanical fans are the way to go are just dead.
I don't know if this is the problem but I'm sure it's not helping-
I took the rad cap off today and noticed some black dust looking stuff. Kinda like the residuals from a black garden hose washer. Anyways, this was sitting around the lip where the rad cap seal sits. I stuck my finger down in the neck and felt a bunch of powder stuff. It kinda felt like mud. I stuck a turkey baster down in the neck and pulled up a bunch of black sandy looking material. I scooped out as much as I could get to onto a paper plate. Later the water had evaporated and what was left resembled black dust. It looked like soot or something. Maybe like the carbon build up on drum brakes.
I opened up the petcock and let it drain into a white plastic tray. There was a little bit of this stuff but not much.
I seriously flushed this previously. I had the tstat out and a garden hose hooked up to a T spliced into the top heater hose and had the petcock completely removed. I ran water through it for hours. Every 20 minutes or so I would start the motor just to agitate things a bit. There was nothing coming out when I was done. The whole time I was letting it drain into that white plastic tub and there was nothing but water.
This evening I tapped into the top heater line with a Y with the main flow diverted to a large transparent fuel filter then ran the line back to the heater line with a T. I routed it this way so that it still had full flow following the normal path in case the filter clogged. I ran the motor for about 20 minutes with nothing showing up the in filter. I then drove it for about 10 minutes and the filter was just under 25% full of the black stuff. I ran a magnet over the filter and found this black stuff is magnetic.
So although some had settled up high in the filler neck of the rad, it is heavy and dense enough that it wont flush. It seems the only way to pick it up is with the agitation of driving.
I gotta work in the morning so I had to stop there. I guess tomorrow I will clean out the filter then go do some more driving.
I took the rad cap off today and noticed some black dust looking stuff. Kinda like the residuals from a black garden hose washer. Anyways, this was sitting around the lip where the rad cap seal sits. I stuck my finger down in the neck and felt a bunch of powder stuff. It kinda felt like mud. I stuck a turkey baster down in the neck and pulled up a bunch of black sandy looking material. I scooped out as much as I could get to onto a paper plate. Later the water had evaporated and what was left resembled black dust. It looked like soot or something. Maybe like the carbon build up on drum brakes.
I opened up the petcock and let it drain into a white plastic tray. There was a little bit of this stuff but not much.
I seriously flushed this previously. I had the tstat out and a garden hose hooked up to a T spliced into the top heater hose and had the petcock completely removed. I ran water through it for hours. Every 20 minutes or so I would start the motor just to agitate things a bit. There was nothing coming out when I was done. The whole time I was letting it drain into that white plastic tub and there was nothing but water.
This evening I tapped into the top heater line with a Y with the main flow diverted to a large transparent fuel filter then ran the line back to the heater line with a T. I routed it this way so that it still had full flow following the normal path in case the filter clogged. I ran the motor for about 20 minutes with nothing showing up the in filter. I then drove it for about 10 minutes and the filter was just under 25% full of the black stuff. I ran a magnet over the filter and found this black stuff is magnetic.
So although some had settled up high in the filler neck of the rad, it is heavy and dense enough that it wont flush. It seems the only way to pick it up is with the agitation of driving.
I gotta work in the morning so I had to stop there. I guess tomorrow I will clean out the filter then go do some more driving.
