fronkatonka

Im not getting any pressure in my radiator:/ . I've changed my radiator cap two times and I haven't found any leeks. What else could it be? Your help would be appreciated

NaStY5000

If its over heating it could be due to thermostat staying closed or blocked/plugged rad and or heater core...........

Gee oh Dee

Water pump? Clogged radiator?

Thermostat as suggested?

Have you only changed caps?

djb383

Not sure what u mean by "pressure in your radiator"....top/bottom radiator hoses should begin to get hard as soon as just a little heat starts to build in the motor. If they don't, gotta leak somewhere/rad cap is not sealing. Pressure should build equally in the block, the head, the rad, the heater core all at the same time as heat in the motor builds.

Do u mean "flow thru your radiator"?

fronkatonka

I took out the thermostat and every thing seems to be okay the only part that sucks is its a bran new thermostat oh well

djb383

Shop manual says don't operate motor without a t-stat.

fronkatonka

Should I just go get another one?

bigvig

Yeah, Im not sure what youre asking either by saying youre not getting any pressure in your radiator. What exactly is going on? Overheating? Engine light on? Have you recently opened the system and forgotten to "burp" it causing an air bubble in the system (good way to burn up a head gasket)? We need more details than "Im not getting any pressure in my radiator".

Also, when you say you took out the t-stat, do you mean you actually took it out and left it out and operated the vehicle (I wouldnt, thats asking for trouble)? If thats a yes, then you probably got a bad t-stat, it happens. Return it and explain what happened. Also, when you change your t-stat, your going to lose fluid and put air in the system, which means youll need to "burp" it.

djb383

It may sound like a hassle and I understand that people have better things to do than watch paint dry or grass grow BUT, testing a t-stat (old or new) is the only way to tell that it's functioning correctly. A small pan on top of a stove with enough water in it to fully cover the t-stat and a cooking thermometer is all that's needed. Put the t-stat in the water and slowly bring the water to a boil. A 195 t-stat should be fully open by +/-212. A 180 t-stat should be fully open by +/-195. Obviously, testing a 160 or 180 doesn't require 212 water temp to bring it to it's wide open position.

In doing the test one can see/understand how a automotive t-stat works. It's very slow to both open and close and if the water temp is adjusted to just above the t-stats temp rating, u can see it "hover" between closed and wide open. There is a infinite number of partial open positions between closed and wide open. A 160, 180, and 195 are all wide open the same amount at their respective wide open temps.

fronkatonka

Okay thanks for all your help. And by pressure i mean the tubing comeing the radiator wasn't as hard as it should be. I wasent geting proper flow which got fixed when the thermostat came out. But when I took it out it was wide open and as it cooled it closed like it should but could it just be that its not opening all the way ?

fronkatonka

What temp are xj's supose to run at??? 210 right

bigvig

Thats debatable, but yes, mines never run over 210 unless Ive had an issue, which was my heater core going on the 4th. Then I lost coolant and the temp ran high. Other than that, in over 9 years of owning my '99, its never gone over 210. Your hose not getting hard could have to do with air in the system. Open it up and "burp" it properly. A "Spill-Free" funnel helps IMENSELY with this. Makes it SUPER easy.

djb383

That's basically where the factory gauge is rigged to point when coolant is with-in normal parameters (range).....kinda like most other factory gauges that have a C and H, needle points to the middle most of the time. The '98 FSM in a nut shell says normal range is 160F (minimum to keep CEL off) up to 218F (where the ECU turns on the efan). Wow, a 58 degree NORMAL RANGE but the needle usually points at 210 (or the middle).

fronkatonka

Well my jeeps a 94 and without thermostat it ran 210 but with it ran around 220 maybe but never went past the white line before red. And the reason this problem presented its self to begin with is because the Efan would turn on often and stay on for a good 30 min after I turn the jeep off.

djb383

CAUTION, CAUTION, CAUTION......if the t-stat was hot enough to be open when u took it out, u were messin' with some really hot stuff.....skin can be badly scalded at 125F.

Coolant expansion (from being heated) is what causes the hoses to get hard......flow from the water pump has virtually nothing to do with the hoses getting hard.

Here are pics of a 180 t-stat both closed/wide open.....160, 180 or 195 t-stats are open the same amount when wide open. Remember, a t-stat only controls minimum temp.