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XJ problems

xj00ny

NAXJA Forum User
Location
Poughkeepsie,NY
Still having cooling issues.Iam about ready to throw in the towel and get rid of it. Still no pressue building in system. Now I noticed that when I am at idle I have no heat, not until I raise the RPM do I get heat out . At idle after about 20 min I get to between the last mark before 210 and 210. Once I rev motor the temp starts falling. While driving it stays hovering at the second mark from the 100 mark. I am going crazy figuring out this everything is new . See my other posts . I am going to begin a bon fire pretty soon with this XJ.:gonnablow
 
Are you sure the thermostat is 100% working? Throw in a Stant SuperStat 195 degree thermostat for kicks. Also are you sure the radiator cap is working correctly? They don't have to always work, you know, just because they are new.

Are you loosing coolant? Any greenish colored leaks? Is your water to antifreeze mixture pretty close to 50/50?
 
Put the match out! I would think if you do not have any pressure. It would seem you have 1 0f 2 problems. Either your leaking fluid somewhere and if your leaking fluid you got be loosing pressure there also. Or your Cap is not holding. Do you smell antifreeze or see white smoke out the exhaust when it's running? Just a couple of guesses. If its 0 or below, after I start it and go 1 mile it's throwing warm air. At 2 miles it's hot.
 
xj00ny said:
Still having cooling issues.Iam about ready to throw in the towel and get rid of it. Still no pressue building in system. Now I noticed that when I am at idle I have no heat, not until I raise the RPM do I get heat out . At idle after about 20 min I get to between the last mark before 210 and 210. Once I rev motor the temp starts falling. While driving it stays hovering at the second mark from the 100 mark. I am going crazy figuring out this everything is new . See my other posts . I am going to begin a bon fire pretty soon with this XJ.:gonnablow

The second mark from the 100 mark is actually 165 F (at least on my jeep, I tested it recently with a $10 infrared tester from Harbour tools).

Several posibilities.

But first, isn't it damn cold up there right now????

If the thermostat is stuck open in that cold weather it will cause your problem. Having to raise the RPM to get heat out, if it is nearly instantaneous sounds like either a loose water pump impeller, or possibly a vacuum problem on the A/C-Heat damper(name?) door, it may be hanging open and letting cold air in from outside (stuck in the vent instead of the heat setting on the door which closes the outside vent off).

How do you know it is not building pressure????
 
Blend doors control how much outside air is allowed to come in, or none at all. If he had a vacuum problem the setting would default to defrost with the heater valve open, so it still wouldn't let outside air in (the top slider.)

Bottom slider is for the blend doors.
 
Blaine B. said:
Blend doors control how much outside air is allowed to come in, or none at all. If he had a vacuum problem the setting would default to defrost with the heater valve open, so it still wouldn't let outside air in (the top slider.)

Bottom slider is for the blend doors.

Are you sure its not the other way around? (I am not sure) But I know I have a screwdriver stuck in my blend door to hold it mostly closed because it does not work and won't close on its own no mater what I do with the controlls (another jeep project for my roundtuit list). Mine is an 87, XJ.
 
Radiator cap. Either test it or throw it away. Visual will not tell you it is fine. Remember use a 16# cap.
 
The bottom slider, which has blue/red is for blend door...It's not vacuum controlled. Maybe the wire that controls it snapped on yours? I don't know, you'd need to take apart the dash to check.
 
Blaine B. said:
The bottom slider, which has blue/red is for blend door...It's not vacuum controlled. Maybe the wire that controls it snapped on yours? I don't know, you'd need to take apart the dash to check.

Not talking about the lower selector at all. When you switch from A/C to MAX A/C (upper selector) there is vacuum operated door that I can hear switching that I am under the impression closes off all outside air. I was under the impresion that same one closed when switching from vent to heat on the upper selector? Am I missing something there?

If so, I guess I will figure it out first hand real soon when I replace the heater core on my 85, and tear out everything in there just to get to the frigging core.
 
No, the door you hear opening when switching to MAX A/C is the door infront of the blower motor (look under the dashboard on the passenger side)

This door allows the air inside of the vehicle to circulate. Aka, it gets sucked back up through that little hole and recirculated through the system.

The top controls do not control inside/outside air. That's what the bottom slider does.
 
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