BBuchta

All XJ's have heat issues at some time or another and there are tons of related threads. I'm wondering if anyone has ever installed a full size truck radiator and modified the front end to make it fit or an additional remote radiator underneath or anywhere else on an XJ. I have tried hood spacers, 2 core rad, 3 core rad, 3- 10" electric fans with shroud, coolant flush, new coolant, water wetter, new water pump, restrictors, and everything else I could think of. My current set up is 3 core rad, oem water pump, 1" hood spacers, removed front skid, new 195deg thermostat, stock mech fan with grand Cherokee clutch with spun spring to stay mostly locked all the time and a new oem electric fan wired to a thermostat to turn on at 200. I run normal temps during normal operation, low speed high speed ect, no issues crawling on the trails either. When pulling long grades out of boost it will slowly climb from 210 to 230-240+ if I let it. If I pull grades in boost with a afr of 12.5 and water meth activated engine temps stay around 210. If I sit idle the fans move enough air to blow some hot air out from under the jeep then suck it back into the grill breathing some of its own pre heated air. You can easily feel this effect standing in front of the jeep. Temps also climb to 230-240+ if stuck in traffic long enough. I'm running 4.10 gears, 31's, supercharged, and AC. The idling in traffic heat creep only occurs when the AC is on. Looking for ideas and experiences.

Tony_SS

Is the temp gauge accurate? Have you tried reading temps with another gauge or a scangauge? Just to make sure you're not chasing a ghost.

Diesel

Lower thermo and switchable e-fan

It does sound as if your gauge may be bad, if you are having heat issues after a 3 core rad there is something wrong.

Tony_SS

Of course a supercharger is going to generate a ton of heat. Especially with the AC on.

Diesel

Missed that, fab a SMIC

s14unimog

I'm sure it's going to be difficult to fabricate an air-air side mount for a roots style blower. However, those charge air temps can get as high as 300*F so I think that needs attention. Check out Frozenboost.com and get you a water cooler. To stack between the manifold. Better for slow speeds anyways...

Diesel

Roots, no thanks.

Water Air Cooler, and toss in a second Evap core, plumb it to the tank.

Similar to fords supercooler design

BBuchta

Believe it on not my charge air temps are not bad, I'm pulling fresh air from behind the headlight. Non boost charge temps run from 120-160. Progressive water meth injection keeps temps 150-180 in boost even when its 90+ ambient.

The temp sensor is ok, I've replaced it also, it actually reads slightly cooler than what it should. I'm running an obd monitor to monitor charge air and water temps. 225 at the obd2 monitor is 235 with my IR temp gun.

BBuchta

I'm hoping to get some input, I'm going to try disconnecting the 02 sensor to force it to stay in open loop all the time and see if the richer AF helps create less heat. The other idea I have been kicking around is a remote mount tranny cooler with fan mounted above the rear axle where there is plenty of room from the lift. Then plumb it to the lines that would normally go to the heater core. My issue with this is I'm worried the water pump wont pump it all the way back there and back fast enough to make a difference, I don't want to overcomplicate things and have to add another water pump...

Also just to add this issue was occurring before the supercharger install, so its not added heat from the supercharger.

Is it possible to have AC that's too cold? I still can't help but think it may be AC related. My ac cools better than most. I have a 2013 Tacoma and my wife has a 2012 Subaru forester and the ac on both of those really lack compared to the jeep. I get 25-35 degrees at the vents on high depending on speed and engine RPM. This is with 95-100 degree ambient temps. The compressor does cycle off and on when the fan is set at anything less than high.

s14unimog

No thanks? Didn't suggest it would be an easy install but seemingly the only option to cool charge temps. Exactly - pretty much your only option for roots.

Right on. Just remember (which I'm sure you already know) that your blower curve is linear to engine speed so of course your charge temps are much higher (depending on pressure of course) above idle. I think its great that you have a meth kit on there but I'd prefer the reliability of a heat exchanger - specifically air-water. It never ceased to amaze me how hot blower temps actually get... To bring a little credibility to my comments, I was a Rotrex supercharger OE for a little over 5 years.

BBuchta

Well I drilled holes and ran bolts to make my fan clutch solid. During my 45 minute commute home in stop in go traffic, 100 degrees out, with AC on it peaked at 235 when traffic started flowing again. It would have continued to climb if I hadn't started moving. Its better than before because it took longer to get to that temp but I'm still not happy with it. Over 20mph it cools down, under 20mph it heats up. When I got home I opened the hood to see if letting the hot air rise out of the hood would let it cool, and found no difference still climbs with AC on. Turned the AC off and it went down to 199 within 5 minutes.

s14unimog

Our stock fans are junk. Even a locked out mechanical. I just installed a 3-core in mine and it's clear now, the fans are the problem with it.

BBuchta

I ordered a 10" 1400 CFM pusher fan online, going to mount it in front of the clutch fan and see if it helps keep things cool at idle. I know it may hurt during high speed, but I'm going to give it a try. If that doesn't work I will mount that fan on a 12"X12" radiator cooler remote mounted under the rear cargo area above the rear axle and plumb it to the lines that currently run to the heater core.

offroadordnance

Have you considered an airdam at the radiator? Built correctly it would create a negative pressure area for air to exit at speed. At idle it would prevent recirculating hot air through the rad.

s14unimog

Right on. It's worth a try. I tried a pusher once on my 240sx and ran into that high speed issue. Once you get going down the road it acts as though its blocking it. Only other advice I've got is to make sure you get a shrouded fan - cover the blade tips. Those perma-cool open types don't **** for moving air.

Another idea; do we really need THAT big of a condenser coil? When I was handling mine the other day, it seems a bit excessive...