The Stovebolt Site Forums The Shop Area Engine Shop water leaking from under bell housing/overheating

Hey guys. Got the newly milled and rebuilt 235 in the truck today. Started up and running good. Then i noticed water leaking from the bottom of bell housing cover. Im figuring its the rear freeze plug. Is there anything else it could be?

Also engine got hot really fast. At least faster than normal. Any info would be greatly appreciated. I wanna find out as much as i can before i jerk the motor out again.

Id bet its the rear freeze plug. That should have been changed,and installed properly when the engine was rebuilt.
Other than that, it could possibly the head gasket, but not very likely.
As far as getting hot really fast,,,,air pocket in the cooling system ??

Marty is prolly right....if you have a heater hose anywhere near,like the cowl area that might leak check that too.

Delux54panel and Hankdogg, thanks for the reply. Im thinking the freeze plug also. Its the only one that my machine shop guy didnt replace. He said it was still good. Imagine that. I know its not coming from the head gasket cause u cant see any water on top of the bell housing or around it. Its coming from inside the bell housing.

Heater hoses are not in use. Just got the one heater hose looped back into the pump from the t-stat.

Also if I do have an air pocket, How would I check or fix it?

Or is it possible that Ive got a blockage of some kind and its causing high pressure that might have caused the leak from the freeze plug?

Pressure test it if you can and crawl underneath and use a good flashlight or led drop light to eyeball that sucker. Unfortunately you will have to pull the trany, but that is the only way I know to verify.

Blockage wise, I am not sure what you would be looking at there. Can't speak to having seen a blockage. Sorry.

Hank

OHHHHH,,BUMMER!! Your mechanic admitted to not changing that one freeze plug. They always look good....from the outside.
You not only have to pull the transmission,,,youll have to remove the starter,flywheel, and bell housing to get to that freez plug. Part of the floorboard may be too high to get to it so youll also have to,(maybe) drop the rear of the engine down to be able to get to it. May be easier to pull the engine back out. Sorry for the bad news.
Good luck,

Ha. Yeah I think it will be easier to pull the engine back out. Spent the Last two days of dropping the engine in and connecting everything has gone down the drain. Had it drive ready too. Everything was hooked up. Ha. One good thing about it is im gettin really good at it. Just a lil frustrating.

Three things to check.
One, look closely at the block deck around the engine to be sure it's not the head gasket leaking. Remember, those engines are slanted back when in the vehicle and the antifreeze/water runs to the back.
Second, why run a hose from the thermostat housing around to the water pump. Just block the holes with pipe plugs. Then, all of the water goes into the block. It's just another place for a leak or a hose to kink or break.
Third, pull the thermostat and drill a 1/8 inch hole in the flange of the thermostat for the air in the system to escape. This will put more water into the system and in theroy, you shouldn't have to add any after the first fill up. Be sure to get it in the clear away from the gasket and flange.

Thanks 6cylindersovertexas, All great ideas. After fixing the freeze plug problem. I will start troubleshooting the overheating problem. Ive been reading through all the pages on here scanning for overheating problems. Got lots of ideas.
Seems the first thing everybody says is air pockets. And drilling the t-stat to correct the problem.
Second, they say that newly milled rebuilt(tight) engines tend to overheat before break-in.
Third, they talk about fan clearance(1/2" or under) should be maintained.

Im looking forward to the overheating problem. But not replacing the freeze plug. Ugh.

Thanks guys for all the help. I will report back after tomorrow. Hopefully with some answers and good news.

I found this topic/thread on the forums. Just for future reference if anybody else checks this topic and has the same problem.

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=626507#Post626507

Hey guys. Im back! Pulled the engine today. Took off the tranny and bellhousing and yep, there it was. I promise it didnt look like this when we painted it. I remember tapping on it to see how strong it was. Here is a link to the picture i took.

Bad freeze plug.

Wow! That sucker looks like a bullet went through it from the inside out!

HaHa! Yeah it did. It was kinda a blessing in disguise. After we pulled the freeze plug, We found that the water in the block was dark brown.

After feeling around inside the block with my finger, you could feel sand-like rust particles about two inches deep. We flushed it out from the t-stat hole and water pump hole then backwards from the freeze plug hole.

Hopefully got it all out. Water was good and clear.

Needless to say we will not be using the same machining guy. This is probably why the thing got hot so quick and overheated.

Also I pulled the t-stat and drilled an 1/8" hole in the flange. Hopefully this will help also in case of the air pockets.

We got everything hooked back up and its ready to start. Got too late tonight to try it out. Tomorrow is another day. ha.

I will post pics and results tomorrow.

When filling it up with antifreeze, you should leave the top heater hose connection off untill it runs out there. This allows it to fill as far up as possible. If you had a new cam installed, you will need to break it in.

Glad you got it taken care of Jason, better to catch it now than down the road when you are a good distance from the house/shop.

Alright. Cranked it up this afternoon. No air pockets. Set the valves and timing. Engine ran like a top. Very smooth. Sounds great. Temp never got above 180. Which is good for the hot humid temps down here in Mississippi. Let it run at about 1800 for break in for awhile. Gonna take it on highway tomorrow to sit the rings. Thanks for all the help guys.

did you by chance remove the petcock/plug on the lower left rear of the block and drain/flush from there? you got the crap out at the level of the freeze plug but there is still a lot of room below that to hold dirt and scale. as an on going test on my 40 i keep plugging away at that plug and i always get crap out after a good bit of driving. i saved everything and im up to about three handfuls of crap and that is only the stuff i caught before it hit the ground. there is a lot of stuff that ends up there and hides out. with frequent spot draining you can remove it as fast as it accumilates.

51 ashton, Thats a good idea. Does the petcock hole sit at the botton of the water compartment? We didnt flush it but we just kept flushing back and forth for awhile with it tilted back to the freeze plug hole. I will pull the petcock out tomorrow and flush again and see how much we left.

ive had a 228,248 and two 235's that didnt over heat but ran warmer than i felt they should have. i have pulled the pet cocks out and nothing came out with the block full of coolant. i was able to drive a 3/16" rod in as far as it would go which was about 5-6". when i pulled the rod out nothing followed it. it took some doing but with persistance i was finally able to open it up and get it to flow. with numerous flushings it finally ran out clear with no chunks. the 59-235 that i just had rebuilt and intalled in the dump didnt flow from the hole wit the plug removed. after two weeks of trying i finally pulled the head. it was solid all the way across and one third of the way forward. it took me another two weeks to finally get it all out of there with some secret boiler cleaning chemicals. yeah they can hold a lot and still appear that the cooling jacket is clean.

for simplicity i dont put the petcock back in. instead i plumb it with a short 1/4" pipe nipple with a full port ball valve with a pipe elbow on the end of that topped off with a pipe plug in the elbow should the valve should come open by accident. it makes it real simple to drain it into a bucket without it making a mess plus you capture all the stuff that comes out for inspection. its not original looking but it very functional.