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I replaced the water pump, fan clutch, thermostat and cleaned things up a bit while I was in there. The problem I ran into in the beginning is still happening.

Yes the water pump and fan clutch were both bad so it should have been fixed...

Truck starts up perfect. Takes a few minutes and it's warmed up to running temp. I drive down the road 30 miles, pull over to stretch, truck instantly starts over heating. Get back in a drive off and instantly goes back to proper operating temp. Got to work, grabbed the radiator hose, revved the engine and there's no water circulating at all. (And yes, I checked to be sure, there is proper fluid level in the radiator and in the overflow). The fan was running and so was the electric fan. Water is not circulating and I have brand new water system parts.

Is there anything on the electrical side of the house I need to check?

I'm not gonna give up on the jeep, this is too easy of a problem to fix. I've got a mechanic shop at the end of my street that guarantees they can fix it.... But I'd kinda like to keep my money.

Any ideas before I turn my baby over to the shop?

RTorrez1

I know that you said you changed out the t-stat. But it can be a bad one that was put in. For some reason the 4.0's seem to have better luck with the OEM t-stats. I would start by replacing the t-stat again with an OEM one and make sure that it is a 195deg which is the recommended temp for our 4.0's. I hope this helps. Let use know the outcome.

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Not a bad idea, but I'm going to burp it first, see if that helps.

I put in an oem tstat, if burping doesn't cure it, I'll take the tstat off all together, run it and rule out an electrical issue, then from there I'll put in a brand new tstat... Only I'll test this one before it goes in.

195 degrees only for me. Not trying to make my jeep a tank, just want it to run properly on oem equipment.

RTorrez1

I just noticed that you also live in South Texas. So you know as well as I do on how hot and humid it can get down here. I run a 195deg t-stat all year round and never had a problem problem with over heating. My temp will run between 210-214deg depending on the ambient temp. The only times that I see it get up to 214 is when the ambient temp gets up to 110deg or higher. The main reason I suggest checking out the t-stat is because you said it doesn't look like the coolant isn't circulating. BTW, 195deg is stock temp for the 4.0.

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So, I checked it all out. After burping it, it took an easy half a gallon. Then, I ran it, about 75mph, from there I went to a dead stop. No over heating at all. Drove at 75 again, then let it come to almost a stop and put it in 4 low and 1st gear, ran it pretty hard. No over heating. Got into 2wd again, 75mph, then about 30 mins later I stopped and got out and checked.... Radiator cap was leaking. Easy pickins, $7.99 and I got an oem cap.

Update to follow

(For now it's sounding like the burp)

RTorrez1

Glad that you got it taken care of.
Just curious how many lbs is the new cap? 16lbs. is the recommended OEM lbs for the 4.0 XJ. Also keep an on the coolant level for a couple of day. Sometimes the level will drop a little for the first couple of days.

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So I still have the same issue now.

Popped out the thermostat, it was bad, put in a "never fail" brand thermostat... Same thing. Is there anything other than 3 bad thermostats that can cause this? If I take the thermostats off again I'm running it until winter with no thermostat.

Replaced everything but the radiator.... But I know it was cycling water when I originally put in the second thermostat.

Help me out guys.

djb383

When u "popped out the stat", what indicated it was bad? Odds of 3 bad stats is astronomical.

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I've only popped out the original, which was corroded and gunked up, then popped out the second one, boiled it at a rolling boil for 5 mins and it never popped.

Put in this new one and water just isn't leaving the hose going to the block.

Is there any instance where the radiator would be the problem? The radiator doesn't leak, and has no debris when you open it.

Gonna pop the thermostat tonight and just go without. I'm sick of the heating issues.

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Curious, how big of a deal is the fan shroud? Mine was broken and I tossed it when I put new parts in.

There's no way that rink a dink shroud was keeping my engine at 210 and not the 230-40 I'm at... But I'll listen

RTorrez1

It can make a big deal. I know that many had over heating probelem with out it. Because the Jeep Cherokee has kind of a crappy cooling to start with any extra cooling can make a difference. But I don't know if that would be your only problem. I believe you said you change everything but the rad. It's possible that there is a plug somewhere internally in the rad that may be cause the flow to slow down?

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Hey man, PM me, you live like 15 minutes from me. I ordered the new fan shroud today. Im still thinking the thermostat isn't working / something else is wrong. The fan cant be the only thing keeping it below 240*.

I will put the new shroud on when it shows up, but in the mean time, Im gonna go with no thermostat so I can see if its the problem. The radiator doesn't have any plugs that I know of to look for. . .

still confused.

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Came home, went to pull the thermostat. . . . No fluid in the top hose. So what now? Is my radiator shot?

djb383

R u saying there's no fluid in the top hose but the rad is full (rad cap off)? The stat is not exposed to boiling water inside the motor so it shouldn't be tested in boiling water. Tossing a stat into boiling water won't tell u the temp at which it begins to open. Stats don't "pop" open....they open/close very slowly and very smoothly. A wide open stat will have about a 1/4" gap/opening.

A properly functioning stat does one thing only......determine MINIMUM coolant temp. The rest of the cooling system components, their condition, along with driving conditions determine maximum coolant temp.

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No fluid at all... I read a few other things about the radiator having clogs and cold spots. . . A brand new OEM replacement is only $65 plus shipping and tax.

What does it sound like to you guys?

I don't have a problem replacing the radiator, but it seems like I'm just guessing at the problem and not actually solving it.

(If i do put a new radiator in, there will be a case or two of beer and BBQ stag, crane or beef, your choice, if either of y'all wanna come)