JeepForum.com

JeepForum.com (http://www.jeepforum.com/forum/)
-   XJ Cherokee Technical Forum (http://www.jeepforum.com/forum/f11/)
-   -   another endlessly overheating xj (http://www.jeepforum.com/forum/f11/another-endlessly-overheating-xj-1397862/)

whadeezlrg 07-26-2012 01:03 PM

another endlessly overheating xj
 
so I have a 95xj 4.0 3"RC lift w/ 31" BFG m/t's w/ stock gearing that has had a reoccurring overheating issue throughout the summer months(over the last 2 years). I have let it get up to maybe 225f before I turn the heat on full blast whether going up a long grade or sitting in stop and go traffic(more so with a/c on in traffic..will hold pretty steady if no a/c), at some points(on long grades mainly) the temp will climb/steady even with the heater running. I've replaced practically the entire cooling system in the last 6 months other than the water pump that is about 1yr old. I live in the high desert of ca and outside temps get to about 105-110f through the summer. running the a/c only makes things worse.

Parts I have replaced:

-3core all metal csf radiator
-mopar 195f thermostat
-new upper and lower rad hoses w/ spring re-installed in lower
-external b&m trans cooler inline after stock cooler(mounted in front of a/c condenser inline with mechanical fan)
-zj HD fan clutch(napa)
-e-fan from junkyard that works great(wired to switch for always on/always off/ stock relay)
-water pump from o'reiley that is about 1yr old
-50/50 antifreeze/distilled h2o
-new 16lb rad cap

I have bled/attempted to bleed out all the air out of the system on multiple occasions letting her run on an incline for up to an hour or more with the rad cap off

I ran seafoam through the throttle body to clean injectors just to be sure things weren't starving for fuel and running lean, replaced plugs with champions 2-3days later (drastic improvement in fuel mileage...that was it)

no check engine lights

block test checked out good

compression is between 120-130 across all cylinders

I loosened the tension on the belt quite a bit, not to the point of squealing

trans does not slip, filter and fluid are less than 1yr old

JY Zj exhaust manifold w/ no leaks installed about 1yr ago

the engine runs great, and I don't hesitate to drive her 1k mi 1way trips when the temperature allows it

had the a/c checked pep boys style...she looked good and still blows cold

heater blows hot enough to make my leg feel like it's gonna melt

coolant appears to be clean, and free of debris, I flushed the system with water until everything flowed nice and clear for a while but did not use a chem flush.

I'm at my wits end, I have to take her on a 1k mile camping trip in about a week and my girl and daughter would probably be much more comfortable if I'm not forced to run the heater any time we approach a grade (going to sequoia and there will be a good amount of elevation to gain in the last stretch)


any ideas would be GREATLY appreciated. let me know if I left anything out.

thanks again!

Omicron_Persei 07-26-2012 01:07 PM

Just a suggestion... have you checked the accuracy of your temp guage? It sounds too consistant to be a bad gauge though. Like I said, just a thought.

DerMeister 07-26-2012 01:23 PM

Hey there, the one thing that comes to mind is the CSF radiator. I have been on these forums for a few years now and several times I have seen the CSF radiator be the cause of overheating despite a new cooling system. You can have it flow tested, or try out another radiator to be sure.

whadeezlrg 07-26-2012 01:23 PM

I thought about the gauge being outta whack but everything is consistent to what it should be. t-stat opens up @ 195f and e-fan kicks on @ about 212-214f so I figured that wasn't it. I haven't sprayed water through the condenser or messed with the fins at all yet but I'm thinking about doing that right now to see if it helps.

djb383 07-26-2012 03:11 PM

The XJ rad, regardless of brand/#of rows, etc., is just really dinky in size (sq. in. frontal surface area/CID). Our cooling system is totally new (stock fan clutch, 180 stat) and in triple digit ambient, bumper-2-bumper traffic, on black asphalt, runnining a/c, we momentarily have seen 225-230 on the ScanGauge.......start moving and hi coolant temp drops quickly/substantially. With triple digit ambiet and your operating conditions, your temp may be as good as it gets. FWIW, the factory idiot light never even flickers at 230.

If coolant level is always at the top of the rad neck, MOTOR COLD, after several heat/cool cycles, the system is burped.

I have no 1st hand experience with the CSF 3 row rad but it is old school design vs the modern design OE style aluminum core 1, very wide row.

whadeezlrg 07-27-2012 11:57 AM

well after driving around town some more yesterday (stop and go, ambient temps around 100f) I didn't overheat at all but I also did not run the a/c at all. I guess I should take a trip down the ol' cajon pass to see if shes gonna heat up on they way up...loosening the drivebelt tension was the last thing that I have done, I'll report back with some kinda results either way.

whadeezlrg 07-02-2013 04:23 PM

shes still getting hot on me...even a year after i first started this thread.

done since then:

changed zj fan clutch back to xj fan clutch because of clearence issues (fan clutch kept rubbing on surface of radiator causing leaks when i'd wheel and get flexy)

I made/fabricated an x-tra cool hood by cutting out 2 large triangular portions of the hoods sheetmetal and welded in some expanded steel to allow air to pass through engine compartment, it helps but a band-aid isnt a solution in my opinion.

when i got it smogged in january it passed but was at the max allowed NOX reading which is tied to high combustion temps...in my mind that means either bad timing or a lean mixture

not much else i can think of trying....getting ready to take her on another camping trip and would really like to leave the heater off this year.

also i remember reading in an issue of jp recently about a new aluminum rad setup w/ 3 e-fans that run in sequence...that may be another possibility although i'd prefer not to have to go that route($$$$) anyone have any experience with one of these setups?

I really feel like my engine is just producing more heat than a fully functional cooling system is capable of controlling.... 225k miles, probably never had the timing chain/gears changed and I wouldn't be all that suprised to find out that shes a little stretched out and throwing things off (if timing is off and the fuel mix isnt fully ignited i would think there would be a chance of the o2 sensor reading a rich mix and thus trying to lean it out, I'm not sure thats actually the way it all works but im literally clueless at this point)

does anyone have any experience with timing causing overheating?

djb383 07-02-2013 09:24 PM

Fan shroud intact/in place?

96xjKing 07-03-2013 12:39 AM

I've recently been told of a coolant called "be cool" , I heard it is supposed to drop engine temps 15 degrees or more in some cases. All of this is by word of mouth however. I have a radiator flush in order before long and I'll probably be looking into this stuff tomorrow if I can find some, when I do it i'll post results etc. whether this stuff works I'm uncertain, however IMO the best route would be to shell out the $$$$ for the flexalite radiator and fans that where in jp awhile back an you mentioned earlier. In my case I only reach around 225f max when wheeling in the hot summer months, and I don't have deep enough pockets for the new radiator an electric fans.

kfretto 07-03-2013 06:19 AM

I don't have deep enough pockets for the new radiator an electric fans.[/QUOTE]

yea considering they want near 1000 dollars for the radiator and fan set up :(

foggybottombob 07-03-2013 09:02 AM

The one item that will have more effect on cooling an XJ than anything is an aluminum radiator. I had a 2 row CSF and a 3 row CSF all metal radiator. The 3 row had marginally better cooling than the 2 row. I have a 260 hp stroked 4.6 liter. It gets hot when you try to use the extra horsepower. I got a single row aluminum griffin radiator rated for 400 hp and most of the time the temp stays at 190 to 195. I made every mod I know of except a tranny oil cooler but the aluminum radiator mod had more effect than all the others put together. Aluminum radiators have much wider tubes than brass radiators. Aluminum is stiffer and can be made this way without the tubes ballooning under the 16psi pressure. So find regular thickness XJ aluminum radiator.

You can sell the slightly used CSF radiator on ebay very easily.

kfretto 07-03-2013 09:15 AM

Quote:

Originally Posted by foggybottombob (Post 15635984)
The one item that will have more effect on cooling an XJ than anything is an aluminum radiator. I had a 2 row CSF and a 3 row CSF all metal radiator. The 3 row had marginally better cooling than the 2 row. I have a 260 hp stroked 4.6 liter. It gets hot when you try to use the extra horsepower. I got a single row aluminum griffin radiator rated for 400 hp and most of the time the temp stays at 190 to 195. I made every mod I know of except a tranny oil cooler but the aluminum radiator mod had more effect than all the others put together. Aluminum radiators have much wider tubes than brass radiators. Aluminum is stiffer and can be made this way without the tubes ballooning under the 16psi pressure. So find regular thickness XJ aluminum radiator.

You can sell the slightly used CSF radiator on ebay very easily.

Yea I went from a OEM radiator to a all aluminum one and that was a huge drop in temperature

jeepster383 07-03-2013 09:50 AM

Quote:

Originally Posted by whadeezlrg
shes still getting hot on me...even a year after i first started this thread.

done since then:

changed zj fan clutch back to xj fan clutch because of clearence issues (fan clutch kept rubbing on surface of radiator causing leaks when i'd wheel and get flexy)

I made/fabricated an x-tra cool hood by cutting out 2 large triangular portions of the hoods sheetmetal and welded in some expanded steel to allow air to pass through engine compartment, it helps but a band-aid isnt a solution in my opinion.

when i got it smogged in january it passed but was at the max allowed NOX reading which is tied to high combustion temps...in my mind that means either bad timing or a lean mixture

not much else i can think of trying....getting ready to take her on another camping trip and would really like to leave the heater off this year.

also i remember reading in an issue of jp recently about a new aluminum rad setup w/ 3 e-fans that run in sequence...that may be another possibility although i'd prefer not to have to go that route($$$$) anyone have any experience with one of these setups?

I really feel like my engine is just producing more heat than a fully functional cooling system is capable of controlling.... 225k miles, probably never had the timing chain/gears changed and I wouldn't be all that suprised to find out that shes a little stretched out and throwing things off (if timing is off and the fuel mix isnt fully ignited i would think there would be a chance of the o2 sensor reading a rich mix and thus trying to lean it out, I'm not sure thats actually the way it all works but im literally clueless at this point)

does anyone have any experience with timing causing overheating?

Go have it block tested to make sure you don't have a blown head gasket.

djb383 07-03-2013 06:33 PM

That's interesting about the single row Griffin rad. The original OE stock rad we removed was a single row (1.25" wide/thick) aluminum core rad that has 30 rows vertically and 15-16 fins/inch, iirc. Wonder if the Griffin has more fins/inch and more rows vertically?

foggybottombob 07-04-2013 09:15 AM

The single row Griffin is rated to handle 400 hp. You don't have anywhere near that. There are different operating conditions where overheating is likely.
1) using a lot of horsepower like when going up a long hill at high speed in high ambient temps. If this is your problem only a better radiator will help.
2) sitting at a redlight down town with the AC on in high ambient temps. If this is your problem then you need better fans and a high flow water pump and high flow thermostat housing.
3) Going up steep hills slowly in high ambient temps. This might take every thing you can do to fix. The last resort extra you can do here is install washer system to spray water or some water alcohol mix on your radiator with a push button in the cab.

The other conditions for overheating that I know of are all less likely than the 3 above.


There are probably cheaper aluminum radiators than Griffin. I have not looked.

There are two main heat transfer factors involved in cooling an engine. One is transferring heat from the block to the coolant. The other is transferring heat from the radiator to the air. The ideal coolant flow rate is 6 to 8 feet per second. At low engine rpm you need a high flow water pump to maintain a high coolant flow rate. Just FYI water wetter and other things like that do absolutely nothing to make your cooling system work better with regards to overheating. The larger tubes in the aluminum radiator transfer more heat to the air than the brass radiators do. That includes a brass radiator with 3 rows.

http://www.arrowheadradiator.com/14_...utomobiles.htm


The time now is 05:03 PM.

Powered by vBulletin Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.