First of all this is not a freeze plug leaking. I already fixed one of those, along with replacing the water pump, thermostat, thermostat housing gasket, bypass hose, and fixing a hole in the overflow tank. I pressure tested and everything looked good so I put it all back together, started the engine and there was still a leak.

It's leaking from what I think is the front facing surface of the transmission. Maybe it's called the bell housing? It's the part right in between the oil pan and the transmission pan. There are bolts that hold together a thin sheet of metal to the main body of this and there is fluid leaking from this crack. There is a small part of the metal that looks like it is bent back a little and this is where the main leak is. I don't know how this metal got bent because the oil pan sits lower and if I drove over something I think there would be more damage to surrounding parts. The bolts are spaced pretty far apart here (at least 4-5 inches) and if I press the vertical (front facing) surface in, a few drops of coolant squeeze out all along the joint.

I'm including two pictures because I may not be making much sense. The blue highlighted bolt is the oil drain plug for reference. The coolant is definitely leaking from where it appears to be. It is not dripping down from somewhere up above. I tightened the bolt in the picture a bit but it didn't have any effect I noticed.

Has anyone heard of a leak from here before and any ideas on how to fix it?

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[IMG]local://upfiles/45786/C8A9B7B31BEE4D758E77C555EE2500D7.jpg[/IMG]

 

It obviously look like a leak at the seam to me. If so, a reweld or a replacement is the only real option. In the interim, try using JB Weld on it for an 'at home' quick fix.

IndyDurango

 

The leak isn't along the weld on the bottom, it's between the two pieces. I don't think they are welded together, otherwise that bolt wouldn't serve any purpose would it? Anyone know if this is actually the tranny or not? Since there's coolant leaking I would think the water jacket runs through there but that wouldn't make sense if its the transmission would it?

IndyDurango, thanks for the JB Weld suggestion. It's probably what I'll end up doing unless I get a better suggestion.

 

Hey dude there are two freeze plugs on the back of the motor. One larger and one smaller. You have to pull the transmission to get to them. Did the shop do this for you?

Also it could be a freeze plug on the head dripping down. But I'm thinking rear mounted block freeze plug.

 

I knew everyone would go for the freeze plugs, that's why I said it was not a freeze plug. The one I changed was inside the FR wheel well but all the other ones I can see look good. I am 99% that this is not the freeze plugs behind the tranny. I wiped the area above this seam and blocked it off to catch any drips coming down and the leak is coming from inside that little bent back piece of metal. When I push on that sheet, drops squeeze out all along the edge, telling me that for some reason, this surface is not as tight as it should be.

 

no it doesnt need to be tight to the point where its sealed... it's and inspection plate. it could be the freeze plugs in the back of the block... either that your you have a leaky hose on the top of the motor dripping down or a leaky head gasket which is leaking out the back of the block. check your hoses for leakage, then feel with your hand on the back of the block where the heads meet the block and see if it's wet. if it is then you probably have a leaky head gasket near the rear of the motor.

 

I was pretty convinced yesterday that the coolant was coming out of the crack in the picture but after work today I'll do the checks you advised.

Wouldn't a leaking head gasket leak oil rather than coolant? This leaking coolant doesn't look like it's mixed with tranny fluid or engine oil.

Anyone tried using the permanent metallic block sealer made by K&W? If it turns out to be a head gasket leak or even a small freeze plug leak that's impossible to get to without pulling the transmission, I'd rather try a quick fix like this, even if it only lasts for a year or two. I just don't have the time, money, or resources to pull a transmission that looks like it weighs as much as I do.

On a side note, does anyone have experience pressure testing a Durango? I'm not actually sure of the proper pressure but the cap is rated to 16psi. If I pump the bladder up to 16psi, though, it doesn't fill the neck tight enough and air just pumps into the overflow tank. When I inflate the bladder to 18, it holds up to a point and this is how I found leaks in the bypass hose, water pump weep hole, etc. but I haven't been able to get it to full pressure without the air just going into the overflow. Should I just shove a plug into the overflow hole and try to keep it from shooting out?

Thanks for the help so far.

 

that seems kinda strange it's bleeding out the overflow hole... you could plug it and see what happens to the 16 psi...

as for your leak, if it is a freeze plug, you'll need to get it fixed asap... the longer it leaks, the more potential for greater failure. when they leak it's from rust buildup on the inside of the motor. when they fail the rust has spread enough to start a leak... the longer you wait, the worse it can get.

as for the head gasket, I had my heads off last summer and had head bolt failure when putting the new heads on. the bolts would not clamp the head down enough to seal everything and I had oil spilling out between the block & head. no oil ever got into the water and vise versa. I ended up getting the ARP head bolt kit for $65 bux. cheeper than factory.

another place to look while your checking for the leak is to look at the rear exhaust manifold studs. they go into water jackets.

 

Ok, so now I feel like a real idiot. I took out the bolt in that inspection plate (I think this is the case where the torque converter is but I'm not sure if that's really called the bell housing or not) and pried it back to let the fluid inside drain out. About 3-4 ounces drained out and I wiped as far inside with a paper towel to get as much of it as possible. Then I stuck paper towels under both of the rear facing freeze plugs (also I think where the rear exhaust manifold studs are) and started the car. I let it run for 15 minutes and drove it about 2 miles and not one more drop of fluid has leaked out.

The previous leaks had dripped a lot of coolant over the top of the water pump and down the sides of the valve covers and I think some must have somehow dripped inside this housing and been trapped in there. Then when I put the engine back together and started it I'm guess the flywheel blew this fluid out the bottom and I thought there was another leak.

I'll keep an eye on it and I'll be checking those paper towels as soon as it's cool enough to get my hands in there but they look dry from above and I don't think there was a leak after all.

Steve, as far as bleeding into the overflow hole, I'm using a Craftsman pressure tester. I've heard some bad reviews of them and I don't know how other testers work but this one has you pump a particular pressur into a bladder and that bladder is supposed to fill the radiator neck tightly. Then when you start pumping into the system, the air comes from the bottom of the bladder and the bladder keeps the air from leaking upward and out of the cap. When you're pumping into the system, you're just supposed to fill it all the way to a line that says "bladder pressure". When I pump the bladder to 16psi, it doesn't fill the neck tightly enough. If I make the bladder bigger to fill the neck more tightly, I would have to just guess how full to pump the system because there's no actual number, only a reference to what you set the bladder to. Kind of lame if you ask me but it was a cheap pressure tester.

Another question if anyone knows: are the two freeze plugs everyone says you can't get to without dropping the transmition the ones you can see above both side of the tranny on the rear of the block? If so I think it's actually possible to get to these as long as you use a rubber expansion plug to fill them because you'd never get a hammer in there. It would be a pain, yes, but I think dropping the transmition or pulling the block would be a bigger pain. If there are other ones hidden directly above the transmition, then that's another story.

Thanks to everyone for the help!

 

Ok, now I understand your tester setup... yeah that is kinda lame having it that way. as for the plugs, an expansion plug may work in a pinch but you would really need to have the right plug installed.

my suggestion at this point is now that the coolant is out of the bottom of the tranny area, keep an eye on it and see if coolant collects there again. the leak maybe so small that its taking a long time to accumulate. the other thing I'd recommend is doing a cooling service... use a good flush additive to ensure that you get all the gunk out. once your done with the flushing, re-fill using distilled water & anti-freeze (i use the prestone 5 year orange stuff and it's never let me down). do not use tap water.