Bubbling coolant

Runeddyrun87

Runeddyrun87

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May 2, 2022
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Bentonville
Hey there as always appreciate all the help in advance.

Got a 06 4.0 nsg370

Coolant is bubbling and it’s overheating.

No visible leaks anywhere

Oil is clean

Oil fill cap clean

Water pump not making any weird noises

Just flushed radiator and put new coolant in

Burped the system

New degas bottle

New thermostat

All the hoses seem to be flowing

If I start Jeep without the radiator cap. I can see the level drop when the thermostat opens. So I know I have flow

Any ideas. I would always assume it be head gasket but the signs are not pointing that way and I hate to do all the work ripping the head off new stretch bolts yodi yodi if the head gasket is fine. It’s definitely got gas or air flowing back up thru the system. Gotta be the head gasket right? No smoke or coolant coming out the exhaust thou and clean oil. ??? Any thoughts
 
Bubbling coolant normally means the radiator cap is not screwed down all the way, is defective, or doesn't have the correct 18 lb. pressure rating. Overheating could mean the coolant level is too low, there are air bubbles in the coolant, the water pump is going, the radiator is clogged, or the radiator is an aftermarket brand. Not many aftermarket radiators cool as well as the OE Mopar radiator does.
 
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Brand new cap What would the water pump be doing to cause bubbling. System is full of coolant. Radiator is stock doesn’t seem to be clogged but ?? Prol put another radiator on it before head comes off
 
Do the head gasket test… if it isn’t that, drain the coolant, flush it out with distilled water and run thermocure through the system. You might have a clog or rust buildup somewhere which that will take care of.
 
One more component you did not list is the fan clutch, mine would give a bubbling sound after it slowly overheated you could hear it just after shutting down the engine, to test the fan clutch is fairly simple just give it a spin and see how freely it spins it needs some restistance and the resistance increases as a valve slowly opens as heat expands the spring coil on the fan introducing more liquid into a housing with something similar to pump veins.
 
Oh man I half way thought you where sending me looking for blinker fluid. Never seen any kit like this. 70.00 bucks at Napa. Testing now

908C58FF-7B26-4F35-A85B-2F42C9FF81C7.jpeg
 
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Survey says ! Bad head gasket. New one be here in three hours. Going take at least that long to get the dam header bolts off. Much appreciated. That took all the guess work outta it.

5264A58C-B65C-4908-8BB3-DDA21A349680.jpeg
 
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Runeddyrun87 said:
Survey says ! Bad head gasket. New one be here in three hours. Going take at least that long to get the dam header bolts off. Much appreciated. That took all the guess work outta it.

View attachment 347509
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Sorry to hear that man… You need to check your head for cracks as well unfortunately. I forget which casting but one of the later ones is known to crack sometimes and may have been the cause.
 
DWR said:
Sorry to hear that man… You need to check your head for cracks as well unfortunately. I forget which casting but one of the later ones is known to crack sometimes and may have been the cause.
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He can refer to this thread:

How to identify 0331 or TUPY head (it's in the TJ General Discussion section). Very informative. I think it also rules out his '06 as being susceptible to that issue. ​

 
DWR said:
Sorry to hear that man… You need to check your head for cracks as well unfortunately. I forget which casting but one of the later ones is known to crack sometimes and may have been the cause.
Click to expand...

Indeed, the this test does not mean that it is the gasket. It means that Exhaust is mixing with coolant, which can be because of the crack as well.
 
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Oh man I thought 70 bucks was cheap. When I’m just throwing money at it


Speaking of throwing money at it.

We are back to the drawing board

Brand new head gasket. New problems

Pulled the head. Water pump and tstat again

Spec torqued everything.

Head Think it was 22 lbs 45 lbs 110lbs exact 11 at 100 pounds. Have to double check that but was by the book

Got it all back together. Now it starts revs to 1200 rpm Then slowly revs higher and higher until 2800. Then I shut it off


All the vaccume system is hooked up

Injector plugs where labeled then double checked against manual after issue started


I about ready to set the thing over fire 🔥


The ol everything can be fixed with a match routine.

I kid. But I am frustrated with it


The Clues to the trouble are. The heater running full blast is producing no heat.

Clogged heater core maybe ? Don’t know why that was cause the rev issue ?


Thoughts


Any body want a free Jeep ?
 
Runeddyrun87 said:
Oh man I thought 70 bucks was cheap. When I’m just throwing money at it


Speaking of throwing money at it.

We are back to the drawing board

Brand new head gasket. New problems

Pulled the head. Water pump and tstat again

Spec torqued everything.

Head Think it was 22 lbs 45 lbs 110lbs exact 11 at 100 pounds. Have to double check that but was by the book

Got it all back together. Now it starts revs to 1200 rpm Then slowly revs higher and higher until 2800. Then I shut it off


All the vaccume system is hooked up

Injector plugs where labeled then double checked against manual after issue started


I about ready to set the thing over fire 🔥


The ol everything can be fixed with a match routine.

I kid. But I am frustrated with it


The Clues to the trouble are. The heater running full blast is producing no heat.

Clogged heater core maybe ? Don’t know why that was cause the rev issue ?


Thoughts


Any body want a free Jeep ?
Click to expand...

Get the cooling out of the picture with RPMs. Should not be related, unless you see any overheats.
Do you get any engine codes?
I got the same problem with RPMs, when i had some vacuum issues. The way i checked the vacuum, was that I put my hand on air intake, to prevent it from getting air, and i saw the RPM didnt really change a lot. Then i searched for vacuum leak and found the source (it was a connector that connects the intake manifold to EGP pipe that goes to the back of the jeep).
 
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