joshgabel

Before you click away please read a little further. i have read for hours on various forums and replaced everything and still running 220*+

2000 jeep cherokee 4.0
187,XXX miles.

In the last 2 days parts replaced :

3 row radiator - from radiator barn
Clear springs cylinder head (new updated 0113 head)
New felpro head gasket
new head bolts
New mopar water pump
New mopar 195* thermostat
new thermostat housing
new temperature sensor
new mechanical fan clutch
New fan shroud
new factory electric fan
new hoses, both radiator, overflow and heater
new radiator cap.
new overflow bottle
belt
spark plugs
all motor fluids, including water wetter coolant additive.
air filter

Side note: truck has been equipped with an aftermarket high flow cat and cat back exhaust, and new 02 sensors, this was done while all was working well.

Diagnosis performed so far:

Electric fan functions per factory

mechanical viscus fan "pulls" noticeably harder as the engine heats up.

coolant looks good and has been changed 3 times in 24 hours to ensure no debris or clogging

thermostat has been changed twice to rule out failure and does open as it should. confirmed with boil test and fluke thermo probe.

Chemical - "combustion gas sniffer test" performed many times at radiator filler, passes each time.

plenty of oil pressure

no presence of coolant in oil.

no MIL or check engine, scanned anyway, no codes.

Symptoms :

It runs great and all other systems on the vehicle are pristine, but after 7-10min of idling (85* outside at night in Austin Texas) it will hit and hold 220* on the gauge. when i connect to obdii port it shows *223, when i shoot the thermostat housing with a non-contact infared gun it reads 219*.

60mph cruise on highway it will cool to 212* on obdII and 210 on the gauge.
all this is with the a/c off.


I am in over $1000 on this repair (doing my own labor) and am puling my hair out, i have replaced heads on 3 friends jeeps with no such issues.

Any advice would help, i really want to hit the trails Sunday.

Atmos

what about drilling a hole in your tstat housing? like a purge hole. I know some people have good luck with this. worth a google search right?
or getting an aftermarket transmission cooler so your trans doesn't add any heat to surrounding areas. I can't think of anything else
that's tough man. I'd worry that it's something incredibly simple. like the needle on the gauge is broken and sits 1/4" too far forward or something stupid like that

rideordie66

You running 50/50 coolant right?

KJamesJR

Probably not the needle... He's confirmed using different sources.

Maybe a blockage somewhere in the motor? Have you done a good flush yet, with actual "radiator flush"?


And this ^

Firestorm500

Since you have replaced several head gaskets, I assume you knew how to put this one on properly. I hope.

If the observed flow through the radiator is good, then the problem must be down in the block somewhere. That's all that's left. You've done everything else surrounding it.

joshgabel

atmos : yes i always drill a steam relief, glad you do as well! and yes B&m tranny cooler with a digital gauge for temp.
rideordie66: yes i am
KJamesJR: yes i have tried, used the cheap prestone junk then found some off brand stuff with acid in it. all this was done prior to new cooing system parts.
Firestorm500: I even borrowed a $700 snapon digital torque wrench to make sure i got it rite. this is what i was afraid of is there a way to diagnose a block problem or is the only way to come to that conclusion process of elimination?

Firestorm500

I was trying to make sure that "Front" on the head gasket was in fact to the front; and the head gasket was not upside down.

KJamesJR

Wouldn't there have to be some major friction going on down there though?

What's your oil pressure reading, and are you hearing additional noise that doesn't fit the "norm".

joshgabel

Firestorm500: there are no indicators or stamping for front or top on FEL-PRO 9076PT1 but i did make sure that everything lined up properly and no passages were blocked.

KJamesJR : 20-25lbs at idle and 45ish at highway speeds, no noises,
compression tests are all 150lbs +/- 5lbs. i have seen many 4.0's with washed out cam bearings, that is not evident on this engine.

rideordie66

What was the reasoning for the new parts? Tell us more before you did the 1k in parts. Symptoms? Evidence? What was your jeep doing before you replaced all that you did in the last two days?

Bbasso

did you read?
https://www.cherokeeforum.com/f2/you...system-144771/

DieselD

A few things I thought of.

Radiator cap. its getting to hot and won't let the pressure off...? Keeping it warm. Didn't see it on the list.

3 row radiator isn't getting enough air thru it? Which side is your trans cooler on? From what I understand more cooling happens on the passenger side of the radiator. If its over there it could cause issues... maybe. Same concept if the AC condenser is clogged with bug guts.

ZINGGG

Running a 195 degree thermostat?

It sounds like you literally have done everything possible.

Have you tried turning on your heater to see if that makes the temperature go down at all?

Atmos

yeah I know. I was saying I bet it's something stupid like that. not specifically that his needle is broken. lol

how does your heater core look? didn't see you mention that in the parts replaced

joshgabel

reason for new parts:
when i got the jeep the radiator had a clump of what i am guessing was stop leak in the filler neck, i flushed it over and over till it ran clean. The cooling system was working well.
a couple weeks went by and i noticed a very intermittent passenger side coolant leak coming from the radiator where the core meets the tank on top.
not knowing better i bought the cheapest ($89) radiator i could find.
the leak went away but the temp was now hovering around 220 all the time.
figuring the radiator was insufficient, i ordered a 3 row. while i was waiting for the replacement i decided to flush the system again. that is when i noticed a burp of air from the system every 5 seconds with the cap off from the filler neck.

i did the sniffer test and it failed, indicating exhaust gas in the cooling system. i pulled the valve cover and there was a visable crack between cylinders 3/4 on the head.

replacement head ordered. installed. also replaced all the other components of the system as i am planning a 20 day beach trip 60 miles from civilization. i wanted to ensure that i wasn't stranded due to cooling issues in the 100*+ days here.

Tranny cooler installed on drivers side. i didn't consider cleaning/replacing the A/C condenser. new rad cap but it is a vatozone cheapy lever style.

Mopar 195* direct OEM replacement.
heater does work quite well, i had it running on full when i added the coolant and did so till the electric fan turned on. allowed the engine to cool completely and topped off coolant.