Coolant Leaking From Bell Housing?

[jerm8]

95 LS400

110K miles

Greetings, so far I haven't seen this one talked about so I would like to find out some opinions wiser than my own. My heater wasn't working a couple weeks ago and I found I was loosing fluid. The reservoir was full so I pulled the fill cap above the thermostat and there was no fluid in sight. I added about 1/2 gallon before it filled! Every now and then I have that hot antifreeze smell outside the vehicle. I finally couldn't ignore it any longer so I put it on jack stands this afternoon to try to discover what is going on. To my surprise I found coolant dripping from the holes under the flywheel inspection plate! There is also residue indicating that it has been so at least for a little while.

I think there might be more than one thing going on here.

First--why wouldn't it draw the fluid from the reservoir?

Second--what would cause it to come out of the bottom of the bell housing?

My only thought about the second is that possibly there is a soft plug in the back of the block that could be leaking, but really I haven't a clue for sure.

Any thoughts??

[python]

heater control valve located on the firewall, if its leaking, and they are famous for going out, then it will drip right down on the back of the motor (front of tranny)......thats my guess

[landar]

jerm, was the engine overheating at all? Seems strange that the system would not pull in new coolant from the reservoir..perhaps a line is plugged?

A closed system should pull from just one source when low on coolant and it should be the reservoir but perhaps the system is sucking air back in through the leak point

therefore bypassing the reservoir. I would also be tempted to get a new cap to make sure the system is properly pressurized.

Let's hope Python is right about the culprit. Sounds very plausible.

Please keep us posted on the outcome.

[jerm8]

The engine did get hotter than usual, but not to the red. Is the heater control valve easy to spot? I did look over the back of the engine compartment, though not specifically at the firewall. I just didn't notice anything wet, or any residue, but will look it over again.

Thanks for the thoughts!

[rtd111]

This is similar to my problem with the SC400 (I just posted a no-reply post). It was suggested previously that the heater control valve may be the problem.

In my case, there is no heat inside, coolant starts escaping (when hot / when under pressure, looks like from around the radiator or reservoir cap) and then the heater gauge climbs to red. Thermostat tested good.

I can't imagine that the heater control valve would be the cause: because even without any heat, the system should work. So I've been looking for something else. Could it be as simple as the reservoir cap?

[python]

both of u need to take it to a shop and have the coolant system pressure checked

[jerm8]

I spent some time searching the back side of the engine and the firewall, but can't see anything leaking. A mirror helps, but it's pretty tight back there. I should have mentioned originally that the heater works fine now because I filled it back up with fluid. I do know that the cooling system is building some pressure, but I will still get it checked. But for the life of me, I still can't understand why it could be dripping from the bottom of the bell housing with no other apparent signs of leakage.

[dscabicky]

I spent some time searching the back side of the engine and the firewall, but can't see anything leaking. A mirror helps, but it's pretty tight back there. I should have mentioned originally that the heater works fine now because I filled it back up with fluid. I do know that the cooling system is building some pressure, but I will still get it checked. But for the life of me, I still can't understand why it could be dripping from the bottom of the bell housing with no other apparent signs of leakage.

Very similar to a problem I'm having with my 1990 LS400. Has been puzzling. Replaced the thermostat but it didn't help. Put cardboard under the car but no leaks. But when I add coolant the heat works at least occasionally. There is pressure in the system...get a whoosh when I remove the cap. Must be losing it when I drive.

[jerm8]

Well, I feel a little silly. I had a friend come over tonight that is much more savvy than I am. One of the first things we did is take the top plastic cowling off, which I didn't do because it was leaking out the bottom of the bell housing. Anyway, I have quite a pool of coolant under the intake plenum. I can see with that amount that it could easily run to the back and drip where it is dripping.

The leak appears to be coming from what we think is the return line coming out of the heater core, thru a pipe that runs thru the void between the block and the intake and ties in just behind and below the thermostat housing. I snapped a photo to try and capture it. With the engine running and pressure to the system he put a little pressure on the connection with a pry bar and it started spewing fluid. Now at least I know where it's coming from. It doesn't appear to be tough to get to, but does anyone know how that pipe connects? Is there an o-ring in there? What seals it? You may be able to see in my photo that there is what looks to be a thin washer or something that is loose where the pipe inserts into the housing. I'm not sure what that is either.

Any more advice would be appreciated! I am certainly glad to know where it is coming from. I would also assume that that is where air is being introduced into the system which would prevent it from pulling fluid from the reservoir.

[vcCUZ]

hey guys just wanted to add something i have a ls400 same problem i found out that there was coolant in between the v8 by the starter and it was leaking down through the tranny to the inspection plate and i have no heat also. and the coolant filler was leaking does any one know how to remove it i cant get it to budge off the front bypass HELP!!!

[vcCUZ]

Well, I feel a little silly. I had a friend come over tonight that is much more savvy than I am. One of the first things we did is take the top plastic cowling off, which I didn't do because it was leaking out the bottom of the bell housing. Anyway, I have quite a pool of coolant under the intake plenum. I can see with that amount that it could easily run to the back and drip where it is dripping.

The leak appears to be coming from what we think is the return line coming out of the heater core, thru a pipe that runs thru the void between the block and the intake and ties in just behind and below the thermostat housing. I snapped a photo to try and capture it. With the engine running and pressure to the system he put a little pressure on the connection with a pry bar and it started spewing fluid. Now at least I know where it's coming from. It doesn't appear to be tough to get to, but does anyone know how that pipe connects? Is there an o-ring in there? What seals it? You may be able to see in my photo that there is what looks to be a thin washer or something that is loose where the pipe inserts into the housing. I'm not sure what that is either.

Any more advice would be appreciated! I am certainly glad to know where it is coming from. I would also assume that that is where air is being introduced into the system which would prevent it from pulling fluid from the reservoir.

yea i replaced that gasket but im still leaking and to find out the coolant filler has a crack in it but has been "repaired" with sealant or gasket maker