Air in the coolant system.

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DeLoreanMan82

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Good day to everyone and i'm new to this group. Anyway my wife has a 2005 Jeep Liberty Limited with a 3.7. She has 329K original miles and runs great. Recently I replaced her overflow container, heater core lines, thermostat, upper and lower hoses and a radiator. I'm hearing coolant flowing through the heater core. I do have heat but when i'm running the A/C and get stuck in traffic, she'll run hot and have to blast the heater to cool it down. I see these Liberty's have a reverse flow cooling system and even tried to pull a vacuum on the coolant system but still seem to get an air pocket. I know I need to try the bleeder screw and I have but is it something I have to open and close and just take my time bleeding? Does opening the throttle just a bit help to circulate the coolant better when bleeding. I replaced her water pump before and radiator before separately in the past with never an issue. I guess because I really opened up the system that now I REALLY have to bleed it. Any help will be great appreciated.
 

eric1514

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I know it's popular in YT videos to see folks turning the air bleed screw when they refill the cooling system, but the FSM makes no mention of this procedure. Instead it says,

NOTE: The engine cooling system will push any
remaining air into the coolant bottle within about an
hour of normal driving. As a result, a drop in coolant
level in the pressure bottle may occur. If the
engine cooling system overheats and pushes coolant
into the overflow side of the coolant bottle, this
coolant will be sucked back into the cooling system
ONLY IF THE PRESSURE CAP IS LEFT ON THE
BOTTLE. Removing the pressure cap breaks the
vacuum path between the two bottle sections and
the coolant will not return to cooling system.

I've never used the air bleeder screw. I just leave the coolant tank cap on tight and run the engine. I check the coolant level and when it is cool enough, I remove the cap and add coolant if necessary.
 

lfhoward

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I have an 08 so I don’t know if there is any change between 05 and 08 as far as the cooling system is concerned. When I tore the dash down to replace the heater core and repair the mode door, I had to refill the system and bleed the air out. The bleeder screw is seized shut on my engine, so I parked on a hill, nose-up, turned the heat on full blast, and ran the motor with the radiator cap off. The radiator fill port became the high point, and after about 15-20 minutes of idling, there was no more air in the system.
 

eric1514

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Also, if it's overheating with the A/C on, verify that the fan is turning on. You don't say whether you have HD cooling or not, but if not, you only have the one electric fan and it need to turn on when the A/C runs.
 

DeLoreanMan82

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Also, if it's overheating with the A/C on, verify that the fan is turning on. You don't say whether you have HD cooling or not, but if not, you only have the one electric fan and it need to turn on when the A/C runs.
Sorrry but yeah, the fan does run just fine. That was the first thing I checked and I should have mentioned it in the post.
 

DeLoreanMan82

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I have an 08 so I don’t know if there is any change between 05 and 08 as far as the cooling system is concerned. When I tore the dash down to replace the heater core and repair the mode door, I had to refill the system and bleed the air out. The bleeder screw is seized shut on my engine, so I parked on a hill, nose-up, turned the heat on full blast, and ran the motor with the radiator cap off. The radiator fill port became the high point, and after about 15-20 minutes of idling, there was no more air in the system.
Sadly it does not have a cap for the radiator itself. Just on the coolant tank only and the bleeder screw.
 

DeLoreanMan82

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I know it's popular in YT videos to see folks turning the air bleed screw when they refill the cooling system, but the FSM makes no mention of this procedure. Instead it says,



I've never used the air bleeder screw. I just leave the coolant tank cap on tight and run the engine. I check the coolant level and when it is cool enough, I remove the cap and add coolant if necessary.
What is FSM?

So since you dont use the screw and run the engine, do you rev it up a bit or just simply idle? I guess you dont hear any cooling flowing in the core when finished huh?
 

DeLoreanMan82

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Good day to everyone and i'm new to this group. Anyway my wife has a 2005 Jeep Liberty Limited with a 3.7. She has 329K original miles and runs great. Recently I replaced her overflow container, heater core lines, thermostat, upper and lower hoses and a radiator. I'm hearing coolant flowing through the heater core. I do have heat but when i'm running the A/C and get stuck in traffic, she'll run hot and have to blast the heater to cool it down. I see these Liberty's have a reverse flow cooling system and even tried to pull a vacuum on the coolant system but still seem to get an air pocket. I know I need to try the bleeder screw and I have but is it something I have to open and close and just take my time bleeding? Does opening the throttle just a bit help to circulate the coolant better when bleeding. I replaced her water pump before and radiator before separately in the past with never an issue. I guess because I really opened up the system that now I REALLY have to bleed it. Any help will be great appreciated.
What is FSM?

So since you dont use the screw and run the engine, do you rev it up a bit or just simply idle? I guess you dont hear any cooling flowing in the core when finished huh?
Oh btw, I have noticed the coolant has dropped in the tank since that day since friday of last week.
 

eric1514

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What is FSM?

So since you dont use the screw and run the engine, do you rev it up a bit or just simply idle? I guess you dont hear any cooling flowing in the core when finished huh?
FSM=Factory Service Manual.

I just let it idle for a minute; not so long that I can't safely remove the cap. Then I add fluid and screw the cap on tightly again. The engine will suck the fluid down pretty quickly. Usually 2 times is enough, each time filling the tank back up to the seam (full mark). Then as you saw, a day later after I've driven the car and it has really warmed up, let it cool and look at the level again. Add if necessary.
 

DeLoreanMan82

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FSM=Factory Service Manual.

I just let it idle for a minute; not so long that I can't safely remove the cap. Then I add fluid and screw the cap on tightly again. The engine will suck the fluid down pretty quickly. Usually 2 times is enough, each time filling the tank back up to the seam (full mark). Then as you saw, a day later after I've driven the car and it has really warmed up, let it cool and look at the level again. Add if necessary.
Well , I definitely appreciate the advice and I truly mean that , and I hate the fact that this has been kicking my ass because I was a Chevrolet mechanic from 1996 to 2013. Never did any real heavy work to a Liberty till after I met my wife with her's. Like , I had mentioned , I even used the vacuum tool that I have , because I specifically bought that back when Chevrolet made the LT1 from 92 to 96. That was a reverse flow cooling system in a nightmare to bleed.
 

DeLoreanMan82

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FSM=Factory Service Manual.

I just let it idle for a minute; not so long that I can't safely remove the cap. Then I add fluid and screw the cap on tightly again. The engine will suck the fluid down pretty quickly. Usually 2 times is enough, each time filling the tank back up to the seam (full mark). Then as you saw, a day later after I've driven the car and it has really warmed up, let it cool and look at the level again. Add if necessary.
By the way, do you do it on level ground?Or does it really matter?
 

DeLoreanMan82

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I would think level is better, but no, where I work on my truck leans slightly to the left and back. Nothing radical, just a few degrees.
I have a slight uphill incline in my driveway leading up to my garage
 

seafish

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I always use an incline sometimes as much 10° to bleed the air of any of my vehicles coolant system.
Just seems to work better for me.
 

DeLoreanMan82

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With my DeLorean its like that. I have to have the back on ramps since my radiator is all the way up front and the coolant tank is all the way in the back.
I always use an incline sometimes as much 10° to bleed the air of any of my vehicles coolant system.
Just seems to work better for me
 

lfhoward

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With my DeLorean its like that. I have to have the back on ramps since my radiator is all the way up front and the coolant tank is all the way in the back.
I love that you own a DeLorean. Is yours the stock engine and transmission or have you swapped them with something more powerful?

"Roads? Where we're going, we don't need roads. I also have a Jeep."
 

DeLoreanMan82

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I love that you own a DeLorean. Is yours the stock engine and transmission or have you swapped them with something more powerful?

"Roads? Where we're going, we don't need roads. I also have a Jeep."
Mine is still the stock engine and 5 speed. I dont need anything more.powerful. I got nothing to prove and beside's, its not slow or fast for its time. A Corvette of the era was 1.4 seconds fast 0-60. I did add a Stage-1 performance upgrade though and its a big difference over stock with the choked emissions crap. Mine now has a cold air intake into a K&N filter mounted in a larger air box, throttle body spacer and a set of stainless headers that flow into a dual in/out stainless muffler with polished tips. Took 9 long years restoring myself and she is very upgraded. Been daily driving for 13 years and added over 85K trouble free miles. I get 30mpg and still run the original Bosch K-Jetronic mechanical miles. Honestly I never fear it will break and i'm not always easy on her also lol
I love that you own a DeLorean. Is yours the stock engine and transmission or have you swapped them with something more powerful?

"Roads? Where we're going, we don't need roads. I also have a Jeep."
 

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cas123

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Good day to everyone and i'm new to this group. Anyway my wife has a 2005 Jeep Liberty Limited with a 3.7. She has 329K original miles and runs great. Recently I replaced her overflow container, heater core lines, thermostat, upper and lower hoses and a radiator. I'm hearing coolant flowing through the heater core. I do have heat but when i'm running the A/C and get stuck in traffic, she'll run hot and have to blast the heater to cool it down. I see these Liberty's have a reverse flow cooling system and even tried to pull a vacuum on the coolant system but still seem to get an air pocket. I know I need to try the bleeder screw and I have but is it something I have to open and close and just take my time bleeding? Does opening the throttle just a bit help to circulate the coolant better when bleeding. I replaced her water pump before and radiator before separately in the past with never an issue. I guess because I really opened up the system that now I REALLY have to bleed it. Any help will be great appreciated.
My 04 coolant tank had a disaster and had to replace it. I have had air in the coolant system and have periodically topped the overflow tank to the cold fill line. It has taken a number of months but it seems I can barely hear it now. It does seem to slowly work its way out. I do not have functioning AC at this point, but the sound was driving me nuts and glad it is pretty much gone. The whole thing started in September I believe and so it has been about 6 months for it to work its way out. I check the overflow tank every week or so.
 

DeLoreanMan82

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Ok, well I have tried everything with my wife's Jeep for the overheating issue with air in the system. Still hear coolant flowing through the heater core at start up. I have bled this thing more than I can count and even had the front end on ramps. One shop did a coolant flush. Didn't fix it. Even took it to a dealership and still overheated when I got it back. Upon further research I came upon a post with the same issue about ONLY using a MOPAR thermostat. I used a DORMAN. I'm going to ask and I think I know the answer, but it should ONLY have been a MOPAR piece. Now looking at the DORMAN unit, I see it does have a bleeder and yes I did install it correctly facing straight up and the notch in correctly. The bleeder on the MOPAR unit looks different and bigger and the DORMAN version? Think that's why?
 

eric1514

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Dorman is never my first choice but with that said, I installed a Murray from O'Reilly. It's all they had and I needed it right away. Temp gauge always sits one tick below the halfway mark. I don't know if the thermostat is your problem. I'm not a very experienced mechanic, but it seems you've tried everything else. My gut tells me your water pump is flaky, and the impeller is slipping on the shaft.
 

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