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so days ago coming home from work the needle moved to hot quickly and i smelled hot coolant by the time i got to my house the colant spilled on the driveway...next day i filled it with water and fired up the jeep and rellized it was leaking from the water pump.....So i went ahead and installed a new water pump and t-stat from o'reilleys auto parts....

but it is still overheating...i assumed it was a faulty t-stat so i put the old one back in and the needle moved to hot.
i did a "boiling tested" in my kitchen and both t-states opens and closed.

after reading up on vague info on the forum...i am assuming that
i didn't open up the air pocket screw and do it properly.
can some one give me step by step instructions on filling it through the air pocket screw. also...i read that i have to use the proper coolant. ( the one i got was a green o'reilleys universal 50/50 coolant)

i want an idea of what to do before i go out and spend more money on coolant..

2007 jeep commander 3.7
90100 miles...


thanks
any advice will be appreciated
 

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also...i read that i have to use the proper coolant. ( the one i got was a green o'reilleys universal 50/50 coolant)

i want an idea of what to do before i go out and spend more money on coolant..
You need to use a HOAT coolant. There only 2 choices available:
  1. Mopar coolant from the dealer
  2. Zerex G-05
You can get the Zerex G-05 from O'Reilleys for about $20/gal.
 

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First off you are using the wrong coolant. I would drain the entire system and start over. You are most likely still over heating because you still have an air pocket in the system
 

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First off you are using the wrong coolant. I would drain the entire system and start over. You are most likely still over heating because you still have an air pocket in the system
Agreed.....this is a must
 

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First off you are using the wrong coolant. I would drain the entire system and start over. You are most likely still over heating because you still have an air pocket in the system
That's exactly what I was thinking. At least during before replacing the pump/thermostat, i'd run some Prestone flush (ensure the heater setting is set to the warmest level; want to ensure the flush enters the heater core as well). I'd avoid ever running tap water from the hose to 'flush' the system. You want to keep the system free from minerals in tap water. Running a few gallons of distilled water shouldn't cost too much.

I typically also pull the radiator hoses from and clean the insides w/ a wired brush, as well as the housing/ports they're connected to. Only then I'd start to reassemble the hoses, thermostat and water pump all together. Next is to use the proper antifreeze/coolant mix (Mopar or Zerex). There after, make sure to properly bleed the system. I typically do it w/ the heater set on, while the engine is running....then after it shuts off, about 15-30mins after, bleed while it's off (squeeze the upper hose). After you've bled the system, ensure to top off the external tank to the full mark. Let it sit overnight, and then the next time you're about to start, check the fluid level and top off if necessary.
 

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Modern engines and cooling systems often trap air in the cooling system after draining and refilling them. If this happens, you likely to overheat until you've worked the air out of the system. After you fill the system, run the engine a few minutes, if its still cool open the radiator and fill it again, a lot of air might have worked its way up there.

I've often experienced overheating right after refilling the cooling system on a lot of vehicles I've owned. I haven't done my Commander yet, but my brother's '07 GC has the exact same engine and cooling system and when we drained and refilled his, he experienced an overheat on the first test drive. We let it cool, popped the pressure cap and filled it with more coolant and he checked it a dozen time over the next two weeks and kept topping it off as the air worked its way out. But after the first time, it never overheated again.

A word on Chemical Flushes:
When its recommended to flush your cooling system, it means to flush your cooling system with water, the only time you need to use harsh chemical additives in a flush if is you have some sort of built up deposits in your cooling system that are bad enough that they are hampering your cooling system. The chemicals can damage seals and hoses, especially if you don't fully flush them out of the system before refilling. If there is no evidence of build up in the cooling system, that needs some sort of chemical to loosen it to help flush it out, why would you put those harsh chemicals in your cooling system? So don't.

A Word on Anti-Freeze:
Do NOT mix anti-freezes, of one type and another.
For the most reliable results, use the OEM recommended anti-freeze, like mention, that is Chrysler Spec HOAT and the only anti-freezes I'm aware of that meet that spec is the actual anti-freeze from the Dealer or Zerex G-05.

Although NOT recommended, you are unlikely to have a problem if you switch to another type of anti-freeze, provided you fully drain and flush the system before switching to another type, so you don't mix it with an incompatible type of anti-freeze.

The Old Conventional Green IAT anti-freezes still are the best protecting anti-freeze, as long as you use distilled water to mix with it and change it every 2 years/30k miles, which no one ever did, that is why we have 2 dozen special new long life anti-freezes.

Avoid GM Dexcool like the plague, even though they have improved it, it still has all sorts of problems. And sadly, all the aftermarket anti-freeze companies are packaging their own versions of GM Dexcool and calling it an universal anti-freeze, which it is anything but. Look at the ingredients on the jug, if it says it contains 2-Ethylhexyl Acrylate or 2-EHA it is DexCool. Sometimes they will list the Industry Spec additive package number, which I forget what it is for DexCool.

Don't rely on the color of the anti-freeze, its just dye, and two totally incompatible anti-freezes can be dyed the same color. As well, two identical anti-freezes can be different colors because the company selling it uses different dyes.

And that is finally that is probably the smartest and safest advice, instead of doing hours of research to figure this all out, and you might still be wrong, just stick with what is proven, the Dealer Anti-Freeze of Zerex G-05?
 

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Just tell you one puzzling one I had , although water pump on it was fine.
* Changed coolant.... flushed system well. Then filled : run it with the heater temp on high (not the fan, the temp), cap on radiator open/off, get to running temp.... let it run @ running temp about 15 min. & fill as coolant goes down & that gets the air out of the system. When seeing no change in coolant level ... you've gotten the air bubbles out. Put cap back on while it's running. Don't turn it off and then put the cap on. Note : keep hands and fingers away from the fan & moving or hot parts.

Then, it didn't overheat as quickly, but still overheated. Changed Thermostat.
Again.. took even longer to overheat, but still overheated.

Changed fan clutch ; vehicle no longer overheated.

I think it was a combination of all 3 things together, that was causing the overheating.
 
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