Mysterious Coolant Leak

[KJownerX2]

Good morning all,
I am new to this forum as of yesterday so please excuse if I am asking a question that has been previously answered.

I have a 2005 and 2006 Jeep Liberty (Limited / Sport). On the 2005 last week I performed a pressure test of the coolant system and found a steady drip of coolant coming from the bell housing/block area in the middle of the vehicle. Once the pressure drops the leak stops. I inspected the rear of the heads and found 1 (freeze plug) on each but both had no visible signs of a leak. Block test was also ran and came back clean. Radiator, hoses, coolant reservoir and water pump are not leaking, only the rear of the engine near the fire wall. The vehicle sat for 3 days during a cold snap here and now the leak is progressively worse.
Once the coolant reservoir tank is filled there is a stream about 3/8 inch in diameter coming from the same area and continues until the reservoir tank is empty.
My question is there another freeze plug in the back of the head area? There is now way that big of a leak coming from the head gasket. Is there something that I am missing that could be pouring water out at that rate from that area. I have limited time to work on the vehicle so just trying to get some ideas before tearing the engine apart.


One other thing, I ran across someone who had posted service manuals for an 05 and 06 KJ but cannot find it now. Any help with this is greatly appreciated.

Great forum and information from what I have seen. Thanks in advance for the help.

 

[LibertyTC]

Welcome to the forum.
FSM here: Index of /manuals/Jeep/KJ
Did I hear water? Cold snap and then leaking coolant- How cold was it?
Using a coolant tester, what is the reading of your current Hoat coolant?
Let's hope your HOAT coolant was strong enough to protect z block.

 

[KJownerX2]

LibertyTC,
Thank you for the information it's exactly what I needed.
Unfortunately yes you heard water. Working on this last week after flushing and trying to find this leak left it with just water but not near the full capacity. There was no damage from that but the leak turned into a steady stream after that. I am pretty sure that I found the culprit and will verify when I get to work on it. There are 3 freeze plugs located on the back of the block inside the bell housing, so pulling the ****** is on my agenda.
Thank you again for the information...

 

[LibertyTC]

Well good luck, & they name them "frost plugs" for a reason!
Without proper anti-freeze protection, lets hope it's only a frost plug.
Looking forward to hear more....post back with some pics of what you find!

 

[KJownerX2]

Update on Mysterious Coolant Leak

Sorry for the late update but wanted to show what I found. The overall job was not that bad on time nor difficulty. The cold snap that hit here in Texas was some of the issue but after getting into this I found more than expected.
After pulling the transmission I did find that 2 of the 3 freeze plugs were leaking. After a close inspection I found that they were not pushed out or split, they were rusted and basically paper thin. The freeze plugs had lost 80% of wall thickness. Once these were pulled, I changed every freeze plug on the engine. I found that the previous owner had added a liquid head gasket repair to the radiator coolant. This additive has small particles to seal a HG leak but it also acts as a abrasive to metal parts. I do not believe in nor use said additives because it just hides a problem and also causes more.
I have flushed the coolant system several times and filled with OEM coolant but the color would never get just right. Well I found out why.

So with that said the following was replaced from this little outing.
-Both head gaskets
-Pulled transmission to replace 3 freeze plugs
-8 freeze plugs on the block
-2 additional freeze plugs on the heads
-Replaced leaking waterpump
-Replaced broken heater core
-Replaced broken radiator
-Replaced lower radiator hose

(flagusa)

 

[Myke]

Wow really went to town on it [emoji1531]

 

[ltd02]

Dang, where you driving that thing in the surf? Seems odd for them to rust like that unless someone replaced you coolant with saltwater...

 

[KJownerX2]

All the head gasket sealant that was put in by the previous owner was acting like sand paper and just grinding these parts down. I found about 3 cups of these particles in the bottom of the radiator. Why some people do things like that are beyond me.
:sawzall:

 

[iDreadnaught]

Update on Mysterious Coolant Leak

Sorry for the late update but wanted to show what I found. The overall job was not that bad on time nor difficulty. The cold snap that hit here in Texas was some of the issue but after getting into this I found more than expected.
After pulling the transmission I did find that 2 of the 3 freeze plugs were leaking. After a close inspection I found that they were not pushed out or split, they were rusted and basically paper thin. The freeze plugs had lost 80% of wall thickness. Once these were pulled, I changed every freeze plug on the engine. I found that the previous owner had added a liquid head gasket repair to the radiator coolant. This additive has small particles to seal a HG leak but it also acts as a abrasive to metal parts. I do not believe in nor use said additives because it just hides a problem and also causes more.
I have flushed the coolant system several times and filled with OEM coolant but the color would never get just right. Well I found out why.

So with that said the following was replaced from this little outing.
-Both head gaskets
-Pulled transmission to replace 3 freeze plugs
-8 freeze plugs on the block
-2 additional freeze plugs on the heads
-Replaced leaking waterpump
-Replaced broken heater core
-Replaced broken radiator
-Replaced lower radiator hose

(flagusa)

Sorry to bump an old post, how did you reach the freeze plugs on the block driver side? Specifically the one that's almost hidden by the engine mount? It's a really tight squeeze with the engine still in, and I will be tackling that job in a few weeks when I get time and the parts in.