Hello everyone,

It seems that the LR powers have decided it may be time for me to fulfill my destiny and perform a head gasket repair.

I will provide the deets however I am pretty sure of what everyone is going to say:

1. Identify the leak.
2. Check the oil.
3. Combustion test (sometimes doesnt yield results)
4. Remove heads.
5. Pressure test the block.
6. If the block is good, plane the heads.

After I completed my intake and rocker gasket replacement I installed Extinct’s mod I noticed gurgling and coolant loss after driving. At first it wasn’t leaking much so I assumed maybe old girl was still thirsty and needed more coolant. Top er off Drove it 80 miles to Milwaukee and temps didn't get too crazy, 210 on the highway, 180-185 city streets, however I pulled off to top off coolant and cool er down for safety's sake.

When I say topped off I mean, if I squeeze the top hoses coolant can be heard just at the bottom of the coolant tank. Topping off literally just meant expansion tank fill up. Got it back home and noticed the coolant level dropped. Since I put more than 12-15 liters I knew she wasnt drinking and she was leaking.

No visible leaks at this point on the ground. Took a flight to NC parked it at the airport. Returned home, topped it off, drove home, and still no overheat.

Woke up the next morning to a puddle of coolant dripping down the passenger cats right past the post cat o2 sensor.

Attached is a photo, the coolant has been cleaned up so it isnt that visible in the photo, but on the frame rail you can see the coolant. It def tastes like coolant.

I jinxed myself in the Extinct Mod Post update. Are these the signs of an external HG leaks? Is the next step to pull the heads?

There is a ton of info on here but it looks like I am going to be performinf the D2 4.6L right of passage.

moral support recommended.

 

Have you checked/replaced the cap on the reservoir bottle? If they go bad they can sometimes allow coolant out of the overflow pipe when they're not supposed to.

 

Check the tank and all the hoses too, cooling system dye and a UV light really helps here.

 

So not sure about the make and model, but I have the aluminum coolant tank. I dont know if its allisport but I will check.

that thought was entertained however I don't have a tube/pipe to redirect the pressure relief of the expansion tank and there were only drips of coolant on the tank. Each refill was about 300- 500 mL so my thought would be that I would see evidence of pressure relief all over the manifold.

I have the pressure tester from AB but I need to identify the adapters required. I believe with that kit I can also test the cap. So I will give that a whirl as well.

I believe the cap is a 16psi cap and per recommendations I have been running with it a half turn full turn backed off.

Thank you for the input.

 

Will do. I am assuming I can pick that up at any auto store. On initial fill up of coolant I troubleshot a leaking throttle body heater plate as I over tightened the silicon gasket purchased from Basin Rovers. I was kind of bummed as I wanted it to work. Once I put the oem gasket in place the leak stopped.

Visually everything was dry after that minus the dried up crusty coolant on the passenger cat and puddle under the cat.

Gotta pick up a uv light too huh.

 

Update:

The oil is clean. No milkshake.

The aluminum tank I have is from Carrs4x4. After reviewing the forums I am going to pick up a replacement cap. I believe this is the replacement cap. Which is helpful because then I can get the appropriate fitting to pressure test the system.

Duralast radiator cap #7520

 

the lower the temps with the mod the lower the level in the coolant tank is, if you keep filling to the full level it will continue to leak out out of the pressure releif

 

redwhitekat can you clarify? So I did the inline mod and haven't seen temps above 188 degrees. I looked at the reservoir and "thought" the coolant was low, but it keeps losing coolant. I thought Head gasket, but are you saying if topped off the reservoir will empty itself to a certain level? What will the coolant level be once the in-line thermostat mod is done?

 

mine was at bottom of tank, but if your is fully empty thats a diff story

 

You may want to consider connecting a hose to the overflow line and running it up the A pillar on the windshield so you can see it. I did that a few months ago when I suspected a truck of drinking coolant and have not removed, coolant level is constant now. I do run 1 turn loose on factory cap (more like 1/4 or 1/2 turn on your tank).