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Discussion Starter #1
First off, I have a 06 3.7 Commander. While idling the heater blows cool air. Once I start driving the heat kicks in until I come to a stop or slow down. I noticed the bottom of the thermostat housing was leaking and I was low on antifreeze. So, I replaced both. Flushed the system for good measure, since it hasn't been done in a while.

Now, the Jeep overheats and the heater still doesn't work. On the plus side, the leak isn't there. Any advice? Bad thermostat?
 

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You may have a bad water pump and/or air pockets. I would check the rad after it has sit over night and top off, along with the overflow tank.
 

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Discussion Starter #3
Thanks for the reply. I just finished burping it and flushing out the air pockets out. Seems to be running normal. Rookie error.
 

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Thats good. Mine always took a few tries til it settled down back to normal.
 

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Chrysler HOAT is that the reddish / orange colored antifreeze that I see in my '07 3.7 L ?

Only had this Jeep since August 2014.
Slowly changing all fluids and lubes.

Slipped on a new set of rear brake pads this afternoon.

skip.
 

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Chrysler HOAT is that the reddish / orange colored antifreeze that I see in my '07 3.7 L ?

Only had this Jeep since August 2014.
Slowly changing all fluids and lubes.

Slipped on a new set of rear brake pads this afternoon.

skip.
That might be the correct coolant. But a previous owner may have put another type of reddish orange coolant in instead. It would be a good idea to change it out with the correct coolant.
 

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Check your O.M., I believe the HOAT coolant is suppose to be changed at 100k miles or 5 years, which ever occurs first. So, if you have the factory fill coolant, you're overdue for new coolant anyway.

Chrysler HOAT, you have to get if from the Dealer, is Orange/Red (appears pink or red in some light). Zerex G-05 is the aftermarket equivalent that is the correct fluid to use as well (i.e. it meets chrysler HOAT specs), is amber or almost clear in color.
 

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I'll bet it was never changed in 90,000+ miles [don't really know. ]

The question remains --:> You did use the Chrysler HOAT from the Dealer or Zerex G-05 for the anti-freeze, [which one would you use ] to be correct and how much is required with the hot water heater in the back ?

I use to have a VW WASSERBOXER Syncro and burping is old hat.

Thanx skip.
 

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I'll bet it was never changed in 90,000+ miles [don't really know. ]

The question remains --:> You did use the Chrysler HOAT from the Dealer or Zerex G-05 for the anti-freeze, [which one would you use ] to be correct and how much is required with the hot water heater in the back ?

I use to have a VW WASSERBOXER Syncro and burping is old hat.

Thanx skip.
I got the Zerex.
 

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Their both the same, and the Zerex is cheaper, so I get the Zerex G-05.

I forget the capacity, do a search I think someone listed it. It should be in the O.M., but that might be one capacity the O.M. might NOT list.

IIRC, when I changed mine, I bought 2 gallons of Zerex G-05 and mixed it with 2 gallons of distilled water. I have the rear heater/ac and I had plenty left over, maybe a gallon or a little more.

Draining is a pain, if you just open the radiator drain, you'll get less than half the capacity to drain out. If you leave the radiator cap on while you drain the radiator, the vacuum will suck all the coolant out of the overflow reserviour, easy way to drain that. If you disconnect the lower radiator hose, that will get a good more out (you'll need to anyway to replace the thermostat, might as well while you do this). I also disconnect a heater hose and blow compressed air down it and the other side to force all of the old coolant out of the heaters and their hoses. Finally, to get the very last, you'd need to remove the water jacket drains in the block, they are impossible to get to without removing other stuff first. Honestly, I think you can blow off removing the drains and be fine, what I found, with the thermostat removed and the bleed port open, blowing compressed air down the bleed port, caused the last of the coolant at the bottom of the coolant jackets to surge out of the thermostat port. Yea a lot of work to get all out.

Another trick I've done in the past in other vehicles it was difficult to drain all the coolant out, I've bought 10 gallons of distilled water (its a dollar a gallon) I've drained the radiator and pulled the lower hose (which usually gets a little more than half), then keep filling with distilled water, runnning the motor till it warms up to circulate it completely, drain again, repeat until it drains clear water. Then I fill with pure anti-freeze to mix with the distilled water still trapped in the cooling system, once I've added the amount of pure anti-freeze that is one half the capacity, then I start to adding distilled water to top it off. Remember you can fill the overflow tank/reservior with what mix of water/anti-freeze you need to even out the mix to 50/50. It takes about a dozen warm-ups/cool downs to overlow fluid into it and suck it back enough to pretty much mix it all evenly.
 
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