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Where is this coolant coming from?

Where is this coolant coming from?

007

Crazy Sr. Respected Jeeper
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Reno, NV
Vehicle(s)
1977 CJ-7 Renegade (Daisy Jane), Levis trim, 304, TH400, BW1339 (MM), D30/Auburn Max, AMC20/Detroit/G2's, 4.88's, 33" BFG MT KM2's, Edelbrock Performer intake, Holley Sniper 4bbl EFI, MSD6, MSD ProBillet distributor, OME shocks, 4" ProComp lift.
I was laying underneath my jeep last night replacing a couple Transmission lines. Well I was underneath there a drop of coolant landed on my arm. I looked up and the whole passenger side exhaust manifold is covered in it. It almost looks as if it's coming out of the two bolts there in the center as part of the emissions.

This picture is looking straight up from the bottom the shiny part is part of the starter.

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This next picture is looking through the wheel well.

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And lastly I found this plug on the side of the block on the passenger-side could this be a block heater?

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As to the third pic......yes, that's a block heater.
 
This is how mine looked like:
15378206od.webp

There was no visible hole, but I do not know how
the hose kept it's place...
 
Forgot to say:
it is heater hose from the heater core, where it goes into the manifold... :D
 
The plug in the second pic looks suspect with the rust and dampness. If you don't have the proper tool to pressure test the coolant system I would clean up the plug and surrounding area and run the engine up to operating temps, shut down and inspect.

As mentioned, the last pic is a heater for the block I have one on my 360 as well.
 
Very common to see leakage around block heaters that take the place of a freeze plug.
LG
 
To clarify, this problem starts above the block heater, but below the heater hose. It's almost at exhaust manifold level as it's on the top of the exhaust manifold as well. I'll get top pictures this evening.
 
Ugh... not good, head gasket or exhaust manifold bolt are my 2 guesses
 
Ugh... not good, head gasket or exhaust manifold bolt are my 2 guesses


I need a better picture. I'll get one as soon as this soccer game is over. It's too high for a head gasket I think.

Could it be those two big bolts in the center of my exhaust manifold that are attached is emissions tubes?


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So here's a better picture of what I'm talking about. These two mystery emission bolts seem to be the center of the moisture. And that may be a coincidence but that's the reality. Pretty much the moisture is centered between the two middle cylinders on that side and it's no higher than these bolts. It does this when sitting. When I run it it dries and then comes back later when it's cool.

20bd4d2889a8a12d2770ea0122881e8d.jpg





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Those look like banjo fittings, the seals could be bad. They should take two copper or aluminum washers each. I would replace both sets.
 
Based on the provided pics and discussion:

I am going to suggest a possible crack in the block...here's why I say that.

You have examined the heater hoses (yes?) and would see a high pressure leak out while the motor is running if the hose had a pinhole.

You will get a drip from the block heater, but you said that's too low on the block...

You have 2 banjo bolts that could seep around the seals, but water is not normally carried in lines like that unless the PO did something really odd. In fact, nothing other than the water jacket, heater core and hoses, radiator, and carb preheat water jacket (in the manifold) should have water in them.

A hairline block crack will leak when cooling off, but not when running...heat expansion will seal a crack and visible water will dry up. As the motor cools, the crack widens and water will leak out.

You may want to GUNK off the motor, add a strong Bright green or Orange dye to the water and run it for about 10 minutes. Block the air from the fan with a piece of cardboard on the side of the motor you suspect while you run it. You should see the trail from where the water escapes.
 
Well both of these are possible. But if I have a cracked block how do I get moisture above the deck line? It seems like there's some freeze plugs in the head? Did I see that? Perhaps one of those has come loose exhibiting the same symptoms you describe?


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sure would be nice if it is a freeze plug in the head instead of the other suggestions. The banjo fittings are supposed to be hooked up to an air pump... no water there.
 
I will be back by the Jeep here before lunch. I will get pics of what caught my eye.


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Well both of these are possible. But if I have a cracked block how do I get moisture above the deck line? It seems like there's some freeze plugs in the head? Did I see that? Perhaps one of those has come loose exhibiting the same symptoms you describe?


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Should have also mentioned a crack in the head as a possibility...Can't really get a good estimate with the pics so far. Still, let the motor totally cool and get some GUNK or similar and wash that side of the block clean...let dry. Start the motor and watch the block...even without a dye in the radiator you ought to be able to find it. But do block off the fan air as this can move the water trail around quite a lot.

If you do see it 'magically' appearing on the side of the head/block (nowhere near a port or plug), then you have found the crack. Often these are invisible to the eye...which is why they heat parts in a 900* oven before checking with dye stuff...
 
Something I have tried with some success, is to completely empty the cooling system including the block, then pressurize the system to normal operating pressure using a radiator pressure tester. Using a spray bottle with a dish soap / water solution, slowly spray the area and watch for bubbles.(spray slowly so as not to create bubbles in the mist) Don't use a brush to apply the soap solution because the brush will cause the soap to lather and makes seeing bubbles very difficult with such a small leak. Naturally, the area around the leak should be as clean as possible prior to doing this. The engine should be warm, and dry, but not so warm as to cause the soap solution to evaporate right away. If the leak is extremely small, soap might not work. I used to use a product called "snoop" when looking for leaks in helium gas systems and freon systems. I don't know if it is still available, but I am sure there are other air or gas leak detectors available from auto supply stores, or air conditioning supply stores.
 
Here's a better picture. Here's a wet freeze plug in the head.

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