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Discussion Starter · #1 ·
Hey guys I have a TJ thats kind of been a headache for and I was wondering if anyone knew what could be up:
Its a 98 TJ 4cyl(yes i know thats the first problem)

A couple of months ago I was driving on the interstate and all of a sudden my waterpump basically blew up, I replaced the Head gasket, waterpump, thermostat and did new spark plugs. However when I still drive it the radiator hose still is hard, it takes forever for the temperature to go up, it doesn't feel like it used to and basically seems like there is air pocket somewhere in the radiator but I've flushed it a bunch of times already.... does anyone have any idea what it could be?
 

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Internet Owner
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Bad thermostat? Even new ones can me bad out of the box.
 

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Discussion Starter · #3 ·
Thanks for the response! U think that would cause the hose to still stay hard? I'll give it a shot one thing I'm worried about is I never checked the head to see if its warped but I thought warping an iron block is nearly impossible
 

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Head warping isn't really that common...

New thermostats can be bad, an easy way to determine is to put them in a pot of water and bring it to a boil. It will open up just before the water begins to boil. Another thing is the thermostat NEEDS a breather pinhole punched into the flat dist surface, otherwise air cannot bleed out from behind it. It's something import auto makers figured out decades ago, yet American car manufacturers fail to see. After you verify the t-stat is working, take a nail or something and punch a small 1-2mm hole in the surface of the disk. When you put it back in, orient this hole towards the top of the engine, and re-assemble everything. It takes about 10 minutes of cruising in my Jeep to heat the engine up to operating temp, so go for a cruise around town (not too far from home) and watch your engine temp. Mine really doesn't change once the t-stat opens up, but as long as it doesn't climb above ~200-210*F then you are fine.

The heater is one good way to determine if your system is heating up properly. Also replace your radiator cap. That and a faulty water pump caused my Jeep to turn into a big mess with cooling issues. Replaced both and I've not had an issue since.
 

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Hey guys I have a TJ thats kind of been a headache for and I was wondering if anyone knew what could be up:
Its a 98 TJ 4cyl(yes i know thats the first problem)

A couple of months ago I was driving on the interstate and all of a sudden my waterpump basically blew up, I replaced the Head gasket, waterpump, thermostat and did new spark plugs. However when I still drive it the radiator hose still is hard, it takes forever for the temperature to go up, it doesn't feel like it used to and basically seems like there is air pocket somewhere in the radiator but I've flushed it a bunch of times already.... does anyone have any idea what it could be?
I'm curious, why the head gasket? And, if you have the head off, why not have it checked at a machine shop?
 

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I know this is going to sound like a no brainer...when you go to take your T-stat out again to check it...look to make sure you didn't put it in backwards.
 
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