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Cooling, running cold mystery to me...

Going to look into the best way to test the temp sensor...

blend door has been researched. I think mine Is operating correctly. I will take a look at that again though.
 
In all realness, how much flow should I be able to feel in the upper hose if I squeeze it with my hand? lower as well? If I clamped either off half way, I should see a noticeable pressure build?
 
Warmed up to a blistering 15 degrees today. I was able to go out and check a few things.
- both hoses to the radiator feel the same temp.
- both hoses to the core feel the same temp.
- engine came up to 200 on the gauge driving around town.
- spun the knob on the heater control. cable driven plenum on the blend box was verified to move
- all this is with the efan disconnected.

TO DO:
- borrow or rent a IR gun to verify temp on hoses, water outlet
- replace failing blower motor
 
At 200 degrees, you should have plenty of heat in the cabin. Does the 1998 XJ have the vacuum operated valve on the engine fire wall that allow coolant to flow to the interior heater? If it does, check to be certain it is working properly. The other reason could be a blocked heater.
 
xjwisconsin said:
In all realness, how much flow should I be able to feel in the upper hose if I squeeze it with my hand? lower as well? If I clamped either off half way, I should see a noticeable pressure build?
Click to expand...

If you are feeling heat in the hoses, your coolant is circulating AND your heater core is not clogged.

Is the issue the heat inside or the engine being overcooled??
 
Honestly I started this witchhunt because of cooler than normal in cab temperature. I have a fair amount of time on my hands, and I am just trying to get all of my ducks in a row while I have the time.
- I would like to IR the outlet ect. to verify that the temp that is being read on the dash is realistic. If the temp sensor is out of wack that could be throwing my e fan on prematurely?
- I will most likely replace the water pump, because I am unsure of the PO maintenance. The rig is now siting at 183,000 miles. It's not going to hurt anything to have a bit of piece of mind.
- I have a bit of an ocd on threads so I am trying to keep all of these questions held in one place.
 
Get one of the small" instant read" meat or cooking thermometers and place in vent.
I keep one in the center vent to check AC output temps in the summer.
Had to pull it out at Thanksgiving to check if the turkey was done...wife has it somewhere now ?
 
Well HUM????

Ok so I'm having a very similar issue.

my 98 I just swapped the Radiator and T-stat after flushing the system. T-stat is a 195 and it gets up there and while in the garage it warms up blows warm to hot, but then took it for a spin after the radiator swap today and it goes from hot to warm to Luke warm to almost cold, but the temp is holding around 195 to 200. When I swap from the defrost hot to face heat it has a delay then sounds like its sucking air then hear a quick flap and turns to heat/face. But like I said sitting there idle its warm rev the motor heats up then when I'm out driving the temp stays the same but the air in the cab is cooling off.
it was fine before the radiator dumped on me last week in the really cold weather.
 
Air lock? Did you run it with the heater on when you refilled rad and is it still full? (The rad not the overflow bottle) Mine also runs 195-200 but the heat will melt your face off even though it's mid-30s here now.
 
I topped off the radiator then added to the overflow bottle. I ran the jeep tell it got up to temp let it cool down twice and the coolant level stayed the same.
 
Just went and opened the cap and was only able to put in about 1/2 a cup into the radiator.
 
Jdogg,

Typing on my phone... Yes I have the same suck, pause then blow. I have found that running with the e fan off is seeming to increase cabin and mech temps. I shot the outlet with An IR thermometer the other day and got a temp around 190. Pressure in hoses still seems meager. I am leaning towards a multiple failure. Water pump taking a dump. Temp sensor just a bit off. Over cooling due to larger radiator and invalid temp readings.
I will also be opening up the blend doors to take a look. When I go to turn down the heat from full hot to cool I encounter a fair amount of resistance. Makes me think there is some binding. I will also go and pick up a stock vac canister as I am running one from an undescript grand Cherokee. When I WOT I get a serious vac loss.
 
When I just swapped out the radiator I stuck with the 2core style. Read a lot of guys that upgrade to the 3core and ended upgrading to a HIFLOW water pump after that due to cooling issues. That was one less thing I wanted to deal with and it was another $60-$120 for a 3core.
The last two days I just kept running it up to temp then let it cool down add coolant to at the radiator the coolant bottle level only budged an inch or so at the most. Last night took it for a spin and seams to be doing good now with putting out the heat. Checked the level again this morning before the wife left for work and it was to the top. Fingers crossed this fixed it.
Yours sounds like a few more issues than mind with the hose temps not being that hot. Mine are HOT after about 10 min of warming up.
my only issue as of right now (knock on wood) is I still didn't do that great of a job on flushing the system. I spent a whole day filling running flushing the gunk out of the system to the point it was pretty muck clear water. This morning looking at the overflow tank and it went from that neon green to a bit dull green.

Back flash 5 years ago. I was picking up coolant and AUTOZONE had Dexcool for cheap and didn't know much about it told the counter jockey I had an XJ and he said ya go for it.
Come to find out that stuff I got was for duramax or alum radiators I guess and it gummed up the whole cooling system baked in the lines. had to swap the radiator and hoses and flushed the heck out of it then. Well all the crap junk that didn't break loose back then in the block over time built up. The wife rolled the jeep last April in a freak ice storm and it started a slight drip and over time this last cold spell it blew it out.
Going to run it tell after X mas and do another flush on the system. YA FUN!
 
Also, and I read someone else post this, if your blower motor is working on ANY setting BUT NOT ALL, your blower motor is fine. You need the blower motor speed resistor (sp?). About 45$ at Auto-Zone. Also a lot easier to replace and a common problem.
 
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