1997 Jeep XJ Country

[Callelle]

Hit the muffler with heat wrap and got some adhesive heat barrier stuff on this thing today, haven't driven it around yet to see if it works but fingers crossed. If I'm honest though, I'm not sure how long the wrap is going to last being exposed on the underside. While I do have additional belly height from the 35s and extra lift, I just feel it's going to be wasted money. If it gets me through this year though, I suppose I can say it's worth it. Perhaps next winter, I'll pull the transfer case and do a better job of putting some heat shielding up and replace the beat up exhaust in the process. Getting it licensed tomorrow, aligned Wednesday, and inspected, hopefully, Thursday or Friday.

[Callelle]

Right when I thought this heep was all ready to go, got inspected, insured and registered all smooth, then the radiator starts leaking. New CSF 2 row all aluminum radiator ordered.

[Callelle]

Glad that I decided to replace my radiator now than wait and hope for the best after Rausch in August, drove into town and it was puking coolant rather than dripping by the time I got back. Either way, new radiator came today and I'm pretty impressed with the quality of it. Gonna tear into it tomorrow.

[Callelle]

Radiator installed, transmission flushed, trans cooler relocated, oil changed, oil pressure sender broke.  Haven't taken it out yet because I need to get some more trans fluid in it, gonna drive it out to Rochester Wednesday for the club meeting. I did have it idling in my shop and it was sitting just a hair above 210 on the gauge, or at least how it used to be. Hopefully this solves my cooling issues, if not, the only things I can really think of to replace would be the fan clutch and the water pump.

[Callelle]

Ugh, I feel like I'm chasing ghosts on my temp issues. Took it out today to a semi-local wheeling spot and over heated twice, both of them going up long hills. I know I need to replace the e-fan because at some points it was spinning fine at full speed, others it would barely be moving, you could stop with your finger and then it wouldn't even try to start unless you spun it by hand to kinda of jump start it (pulled the plug for the thermostat to force it on). The other weird thing I noticed is that when my gauge on the dash was reading 260 and the "check gauges" light was on, I got out, opened the hood and nothing was boiling over in the over flow bottle. Honestly it doesn't look like the fluid level has changed at all in the bottle since I filled it. My Jeep only has 93k on it and I'm not getting any leaks or noises from the pump so I'm not really seeing how that could be bad. Anyone have any ideas/suggestions?

[MrMindless]

What # rad cap do you have on it? I run a 24-26 on the buggy, so it will barely be boiling by 250-260... Much depends on water flow vs sensor location too. I'd expect some water to have gone to overflow at that temp though.

Is the system fully bled of air?

Replace the fan and go from there, it's a problem that exists. Might be enough to take care of it. Or course, XJs aren't known for good cooling....

[Callelle]

It's got a 16lb cap which is what it had from factory. Sensor is located in the thermostat housing and should automatically bleed the air out of it because of the small notches in the top of the thermostat itself.

Plan right now is to replace the electric fan, temp sensor, and put a stronger mechanical fan clutch from a ZJ on it. I know that XJs don't have  the best cooling system but there are also ones in a lot hotter places and carrying a lot more weight than I am that don't run at 220* just driving down the road.

[Wingman]

I'd bet there's an air bubble in the system.  Park it on a really good incline and pull the upper hose.

[Callelle]

I'd bet there's an air bubble in the system.  Park it on a really good incline and pull the upper hose.

Just pull the upper hose or pull and run it till coolant comes out? Also better to pull it from the radiator or from the thermostat housing?

[smichaelR22]

too much glycol in the system can hurt too, but sounds like air

[MrMindless]

Drive it to the hill with the rad cap off so it doesn't build pressure. park WAY nose up (like 30-35Ëš) and see how much air you've got in the rad. I bet it's not plumb full.

In the future, maybe filling it at the cap nose-up like that could prove to be enough, but considering current circumstance, I'd pull the upper hose off and fill it at the block there if it's not plumb full. Get as much in there as you can, put the hose back on, and then get as much in there as you can.

Get it warmed up with the cap off, then tighten the cap for cooldown. That way you get maximum expansion when it heats and it will suck in from the overflow as it cools. If you have a cap that you can release pressure on, that can help with this game a LOT. I haven't proven it through years of use and mud exposure yet, but this has helped me bleed 571's system quickly and easily (I run a 24-26# cap. HD parts):

http://www.amazon.com/Stant-10331-Lev-R-Vent-Radiator-Cap/dp/B000B8LKZ0

BTW - at 16psi, I'm pretty sure you would be boiling at 260 if it wasn't reading a bubble.
Okay, I just found a chart that says plain water boils at 260 at 16psi. So actually you could be seeing an accurate reading there... But I still doubt it and think you have air.

[Callelle]

I did what you said Mike, drove it to an incline with the cap off. Didn't see anything other than 2 small little bubbles. Also got it warm with the cap off on the incline and shut it down/replaced the cap. Hopefully this helps a bit. Didn't drive it around afterwards because I was busy fixing the rear bumper and popping a dent in my rear quarter panel out (got my first "real" body damage yesterday  ), so I'll putz around with it tomorrow and see if it helped. Still plan on doing the ZJ clutch fan, temp sensor, and electric fan once I get prices from Arie. A friend of mine mentioned that the air/fuel ratio being off could be causing it to run hot as well. My o2 sensors are only 2 years old but I was having check engine lights come on for the o2 sensor heater, though no codes for the o2 sensor itself. Would that be something that could cause the engine to run hotter than normal?

[MrMindless]

inaccurate O2 readings could make it run richer (cooler) or leaner (hotter) than it should.

[luvmyxj]

can you feel coolant running through your hoses? if not your pump is bad or your coolant bottle cap isnt sealing right. correct me if im wrong but shouldnt the radiator cap be on in a closed system?

[Callelle]

can you feel coolant running through your hoses? if not your pump is bad or your coolant bottle cap isnt sealing right. correct me if im wrong but shouldnt the radiator cap be on in a closed system?

The hoses are definitely hot, and have coolant in them, I don't know so much about being able to actually feel coolant going through them (haven't really felt for that). Open systems still have a radiator cap.