Xj people step in here

toyota1

toyota1

Well-Known Member
Joined
Apr 17, 2008
Location
Fort Mill, SC
I have a 2000 xj sport 9k on a fresh motor and basically all new related parts. So with a new stock cooling system it always shows 210ish on the gauge idle on 95* day it gets to a little over 210 and stays. Two days ago i put a two core champion rad, flowcooler waterpump, 180* tstat, zj fan clutch still runs the same maybe a touch cooler cruising. Is this normal? My main reason for this is it runs really run when i crank it heat soaked even with heatshields on all the fuel parts. Any ideas to fix this?
 
Non ethanol fuel.
Hood vents.

210 is designed operating temp. Do you have the factory heat shield over the dual manifold cats and under the fuel rail on the intake?

Specifically they had a tsb about insulating the injectors with a little cardboard wrap. @Jody Treadway knows more about it.
 
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210 is where it should run. Jody would be the man to talk to..... Those late model's seem to have a problem with heat soak.....
 
Yea the heat shields are still in place plus i have the dei kit that wraps the rail, each injector and a aluminum shield around the manifold. Injectors are new as well
 
Try lifting the back of the hood up about 2" with spacers and longer bolts. If it fixes your issue, you could leave it or put in hood vents. Also double check fuel pressure.. they'll tend to heat soak worse if the pressure is low.
 
210 is what it’s supposed to run at. Also, if you’re going off the factory gauge it could be 220 but would read 210 anyway just cause they’re dummy gauges for folks that don’t know anything, so they don’t go running back to the dealer anytime it got just a little warm. 215-220 would be normal cause the fan would come on and bring it back down like it should, they just programmed it so the gauge doesn’t show that.
My XJ has an aftermarket gauge and it’s funny to see it fluctuate depending on my driving and conditions vs what the dash gauge reads. I have a switch that turns the fan on all the time, and when off it cycles like normal. Even if I turn my fan on all the time it stays at 200* but the dash gauge would say 210*.

As for the heat soak, it’s a pin in the butt to solve. Hood louvers, fuel rail wrap, re-routing fuel lines, all of none of those could work.

Make sure you have a good fuel pump too. A weak fuel pump can cause it to be worse as I recently learned on my YJ.
 
I guess hood vents are my next move. Fuel pressure is good. I actually just hooked the factory gauge back up i did have rigged autometer gauge in for a little while, that's where my numbers came from
 
Most XJs run at 210 regardless of what you do. I had issues with an aftermarket 2 row from csf. It actually had less surface area and volume than the stocker. It would overheat constantly. Went back to a stocker and that helped. It would stick around 190 around town but would shoot up past 210 on the highway. I went to a mishimoto 2” thick radiator and that seems to have helped it, but I haven’t been able to drive it since it’s been over 90 outside. Besides the bigger radiator I have a flowkooler pump, high flow 180 thermostat, and a Volvo fan in place of the clutch fan. Sits around 183-190 most of the time.

As for heat soak, I ran hood vents and it seriously helped my intake air temps but water would work into the injector connectors after a rain and cause a misfire. You could also get more of the dei heat shield and make a shield to go underneath the intake, that may help reduce some heat soak. Unfortunately the extra heat from the dual cats after the manifold on the 00-01s contribute to most of your issue, and there isn’t really an easy way to get rid of them.

One of the jeepspeed guys out west started making and selling billet aluminum 4.0 fuel rails. The aluminum would help dissipate some heat, but I doubt it will be enough to make a difference. NRT Autosports is the company.
 
If you don't want to spend the money on hood vents (I never did), you can also buy four 2" spacers and longer bolts and space the hinges off the hood. Or hood off the hinges to be more specific. It's a cheap way to make a cowl hood and it allows the heat to escape from the highest end of the engine compartment. If it doesn't work, or you decide to sell the Jeep you can always remove the spacers, put the original bolts back and it's like it never happened. A lot easier than patching holes in the hood.
I don't have, or I really can't find any pictures of that mod. It has been a very long time since I've done it; since I washed my hands of XJs about 10 years ago.
 
Also did the hood spacers. It worked great. Also helped the window defrost faster in cold weather. The biggest difference in the engine temp I found was getting the trans cooler out of the radiator and going to a remote mount w/ it’s own fan. That knocked about 20* off the operating temps.
 
Don't ask me how I know this...but if you um, er, maybe like remove the cats under the manifold and um, er, uh, relocate them to a more functional location, the heat soak goes away. This works 10/10

Otherwise, it will be a constant battle under certain driving conditions trying to keep the heat soak issue at bay. No matter what heat shields, vents, etc. you try, you cannot easily overcome 2 scorching hots cats so close to the manifolds and the rail. Without a return line, the boiling fuel stays in the rail and creates an air pocket.
 
I guess for now im just gonna wrap the cats and down pipe and sleeve the whole fuel line to the firewall before i start the process of relocating the cats and 02s since my future long arm plan may change the exhaust route anyway. Thanks for the help
 
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