I smell antifreeze!!
04-12-2019, 06:54 PM
#41
Super Moderator
^I think the 1st thing I would do to set my mind at ease as a quick check, is to take off the radiator cap and check to see if there's any oil floating in the coolant. Those connections at the firewall to the heater core are definitely suspect but they're a PIA to reach and inspect. I remember when I was trying to back flush my HC, I thought to myself, "Oh I'll just disconnect these HC hoses at the HC connections. That lasted for about 20min before I said, "F this!" and disconnected them on the engine block side.
04-12-2019, 07:06 PM
#42
JK Jedi
Those connections at the firewall to the heater core are definitely suspect but they're a PIA to reach and inspect. I remember when I was trying to back flush my HC, I thought to myself, "Oh I'll just disconnect these HC hoses at the HC connections. That lasted for about 20min before I said, "F this!" and disconnected them on the engine block side.
04-13-2019, 06:03 AM
#43
Super Moderator
Are they similar on the 3.8L? They look pretty easy to access right there on mine, and only have a simple pressure clamp. That said, I've never had to touch them at all. Maybe they are on some barb nibbles that are a pain in the ass? It seems though, that Nonblonde should be able to observe a leak there or not. Pulling the rad cap deg is a good idea since it takes all of 30 seconds, and it should be easy to identify oil in coolant.
It is a similar situation as replacing the EGR valve on the 3.8L. It's only 2 bolts holding it on and it looks easy but getting tools in there and having enough room to work on it tends to be the bigger challenges. For my EGR I removed my entire battery tray assembly and the fender liner to finally give me some comfortable working space and access to be able see what I was doing and get a pair of vise grips on those 2 bolts. I envision it being a similar situation with those 2 hose pressure clamps of the heater core.....and if your luck is anything like mine, those tabs on the clamps you need to squeeze with a pair of pliers will be facing in the exact opposite direction you would like them to be.
Last edited by Rednroll; 04-13-2019 at 06:41 AM.
04-13-2019, 08:15 AM
#44
When I was looking at the pics, that was my initial reaction of it being the lower intake manifold gasket leaking but then I saw she has a 2013 with the 3.6L. I suppose the 3.6L has a LIM which could leak but so far I haven't seen anyone ever run into that problem on the 3.6L. Possibly the upper intake manifold gasket rings are leaking.
My LIM was leaking at the front of the engine, where coolant was running down the sides of the oil pan and spraying backwards onto the trans. No reason why a LIM leak couldn't happen closer to the rear of the engine and blow back onto the trans further but based on not ever seeing anyone report replacing a LIM on a 3.6L I have my doubts that is the problem.
However, being somewhat unfamiliar with the 3.6L I just watched the intake removal video below and what I noticed is that Oil Cooler housing is located under the Upper Intake Manifold and that thing has been a pretty common failure item of it cracking on the 3.6L where I believe coolant and oil runs through that thing. It would be good to check the oil level to see if it's low and put some of that leaking coolant between your fingers to try and determine if there's any oil mixed in it, as well as check the radiator to see if there's any oil floating in it. Aside from that, I would guess the hoses connecting to the heater core since it seems to be coming from the back of the engine and would be a much more friendly diagnosis.
My suspicions:
1. Cracked Oil cooler housing
2. An Upper intake manifold gasket leaking
3. Heater core hoses
4. Then prey it's not a cracked block.
Starting around 20:42 shows where they pull off the upper manifold with the oil cooler housing residing under it.
https://www.youtube.com/watch?v=F5cNQ5bpuk4
My LIM was leaking at the front of the engine, where coolant was running down the sides of the oil pan and spraying backwards onto the trans. No reason why a LIM leak couldn't happen closer to the rear of the engine and blow back onto the trans further but based on not ever seeing anyone report replacing a LIM on a 3.6L I have my doubts that is the problem.
However, being somewhat unfamiliar with the 3.6L I just watched the intake removal video below and what I noticed is that Oil Cooler housing is located under the Upper Intake Manifold and that thing has been a pretty common failure item of it cracking on the 3.6L where I believe coolant and oil runs through that thing. It would be good to check the oil level to see if it's low and put some of that leaking coolant between your fingers to try and determine if there's any oil mixed in it, as well as check the radiator to see if there's any oil floating in it. Aside from that, I would guess the hoses connecting to the heater core since it seems to be coming from the back of the engine and would be a much more friendly diagnosis.
My suspicions:
1. Cracked Oil cooler housing
2. An Upper intake manifold gasket leaking
3. Heater core hoses
4. Then prey it's not a cracked block.
Starting around 20:42 shows where they pull off the upper manifold with the oil cooler housing residing under it.
https://www.youtube.com/watch?v=F5cNQ5bpuk4
04-23-2019, 04:49 AM
#45
FYI we have a winner.. but something is still amiss. I put my jeep on a lift this weekend, hooked up a pressure tester and it came pouring out like a waterfall. To set my mind at ease I brought it back down and bypassed my heater core and tried again, held pressure and most of the antifreeze. Left that bypassed, continued with other work, changed out my thermostat and housing (cracked the first one plastic POS) hooked everything back up and the thermostat housing is leaking .. terrified to tighten it down more and crack this one too. But the main thing leaking was my heater core, never smelled coolant inside and never had any leaking inside.
04-23-2019, 04:58 AM
#46
JK Jedi
Was it leaking from the lines running to/from the HC? I presume not from the HC itself or else it would be inside the cab. So HC is blocked up, pressure builds in the lines as it can't get through, and hemorrhages out somewhere in the engine bay?
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
04-23-2019, 05:23 AM
#47
Super Moderator
Was it leaking from the lines running to/from the HC? I presume not from the HC itself or else it would be inside the cab. So HC is blocked up, pressure builds in the lines as it can't get through, and hemorrhages out somewhere in the engine bay?
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
However, a common weak point source of the HC leaking is where those tubes connect to the HC at their elbow joints. This is the reason when I had to replace my HC I decided to put some JB weld around those joints. Many have described that when there HC was leaking, coolant had came out from it in a mist and therefore it wasn't puddling down on the floor boards. I believe I mentioned earlier most tend to notice there is a haze on the windshield from the coolant spraying out before they notice puddles in the floor board area. The OP showed coolant leaking in the trans area which makes sense if it was the hose connections which are difficult to reach.
This is where I tried to goop as much JB Weld around those elbow joints on my HC replacement.
Last edited by Rednroll; 04-23-2019 at 05:27 AM.
04-23-2019, 05:25 AM
#48
Was it leaking from the lines running to/from the HC? I presume not from the HC itself or else it would be inside the cab. So HC is blocked up, pressure builds in the lines as it can't get through, and hemorrhages out somewhere in the engine bay?
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
When you replaced the thermostat, you cleaned the mating surface on the engine so it's getting a good seal? The torque spec for the thermostat housing bolts is 28 ft lbs.
05-31-2019, 06:45 PM
#49
JK Newbie
Join Date: Feb 2019
Location: Gainesville, FL
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I kept smelling a slight coolant smell after my 2015 JK Sport had been driven in the Florida heat. 2nd owner with 45K miles. Never smelled anything in the cab, only from outside. No visible leaks, coolant levels OK and temp gauge fine. Took it into the dealership for the airbag recall and had them take a look. Heater core is the culprit. $1300 estimate if I didn't have the extended warranty.
06-01-2019, 04:16 AM
#50
Super Moderator
I kept smelling a slight coolant smell after my 2015 JK Sport had been driven in the Florida heat. 2nd owner with 45K miles. Never smelled anything in the cab, only from outside. No visible leaks, coolant levels OK and temp gauge fine. Took it into the dealership for the airbag recall and had them take a look. Heater core is the culprit. $1300 estimate if I didn't have the extended warranty.
Makes me start to wonder if the engineers are part of the sales team. "The dealerships need some more service work revenue, let's come up with some good strategy plans". "How about we just call the engine manufacturers and tell them to start leaving the casting sand in the engine block again?" "Brilliant! Won't cost us anything as well!"
Last edited by Rednroll; 06-01-2019 at 04:23 AM.
