V1 Coolant leak between engine and trans!?!?

[ah.b.normal]

Ya kno, IF something HAS perforated the back of the block into the water jacket(very likely an errant bolt) it's probably a small hole; you could just grind/drill the hole round and thread the hole for a steel or aluminum plug w/ sealant and it's zoom zoom time again! I have helped repair an iron block with a kit that uses drill bits, plug taps and multiple overlapping plugs. We filled a 6" freeze crack in an iron block. Beats pulling the engine from a old John Deere tractor.

 

[PHENDERSON]

Tried the dye tracer. Didn't help me much. Nothing on top or on the exterior is leaking. Here is a picture of how fast it's draining out. It's coming out of the hole where you can see part of the flywheel so it seems like it's inside the bell housing somehow. I still don't see any trace of mixing of coolant and oil. I checked around every hose connection and thermostat housing and oil cooler etc. I wish I had an xray machine.

 

[Ross]

Porous block? If it is just the water jacket, you should be able to fix it with epoxy.

 

[PHENDERSON]

I wish it was easy to take the trans off. Maybe I'll dump some fix-a-hole in my coolant system and see what happens.

 

[comegetjoe]

I wish it was easy to take the trans off. Maybe I'll dump some fix-a-hole in my coolant system and see what happens.

Not sure I can reccomend that solution. It sucks, but Id definitely say pull the transmission and pressurize the system and get 100% truth in your answers.

 

[ah.b.normal]

Could one of the upper bell housing bolts be too long and has punched into the water jacket?!! If that is the case fill the cooling system (you prolly don’t need it running.) take each of the bell housing bolts out one at the time and see if coolant comes pouring out! I think there is only water jacket behind the two top bolts straight down from the head. You can run the engine with a couple of bolts out SO LONG AS THE REST OF THE BELL HOUSING BOLTS ARE TIGHT! AND DON’T drive it! Reinstall all bell housing bolts before driving any car! ****I have seen block seal work but if it’s leaking that fast it’s a fair crack. Could it have frozen? I don’t like block seal, it could seal up more than your problems!! It works by filing in any gaps where there is a pressure drop. The calcium in the mix will stay liquid in hot water but where it leaks the coolant water phase shifts to steam and the calcium wants to fall out of suspension, the calcium sticks to and builds up in the exit point until it actually blocks the hole. There isn’t much area behind the flywheel that is the outside wall of the cooling jacket. The only way is to pull off the trans and clutch assembly and the flywheel. Maybe you can use one of those inspection cameras in there? I paid $80 for one at harbor freight. It has ID’d many 4.8 LS motors for me. (A 5.3 has a dished piston and a 4.8 the crown is flat. Pretty easy to see with the bore scope and a piston all the way down.) I am really curious as to where this leak comes from!

 

[escapepilot]

This is a strange one. I don't recall there being anything inside the bell housing area concerning the coolant system that is serviceable. I would hate to pull the engine unless I was 100% sure that is where the problem is. There are a lot of places it could leak above the transmission and both Chevy and DF did a good job of filling that are up with hoses and wires and such.

Does one of the bell housing bolts penetrate the water jacket on the block? I can't recall. If so, it would need sealer.
Could a leak in the oil cooler above the transmission allow water into the bell housing?

I have a spare LSJ in the corner. I'll take a look when I get home and see if something looks like a potential area to check.

 

[Robinjo]

Pulling the engine is a 1-2 hour job. I'd do this and then pressure test the system to see where it's coming from.

 

[Gtstorey]

I'd pressure test before pulling the engine. It's a lot easier to find leaks when everything is cool. I'd be very surprised to find anything between the motor and trans leaking unless they were never separated during the build and the problem goes back to it's previous life.

 

[escapepilot]

Pulling the engine is a 1-2 hour job. I'd do this and then pressure test the system to see where it's coming from.

1-2 hours out if all goes well plus putting it back together plus trying not to scratch, chip, break anything.

 

[Robinjo]

1-2 hours out if all goes well plus putting it back together plus trying not to scratch, chip, break anything.

True.....

 

[PHENDERSON]

Well, I think I do have coolant in the oil pan now. I checked before by letting a little out but after sitting for a couple days the coolant and oil must have separated and now the first thing to dribble out of the oil pan plug is orangish thin oily substance. Head gasket or cracked block. The engine idles normally until it gets hot. I haven't noticed any white or sweet smelling exhaust. Time to start taking it apart again. I wish they still made new lsj engines. I'd probably just go that route.

 

[Desert Sasqwatch]

This doesn't sound good. Not to be too negative, but if there is coolant pouring out of the block behind the bellhousing and coolant in the oil it may be a cracked engine block. I hope I am totally wrong about this, but you may need to look for that alternate engine - sorry to bring this up.

 

[ah.b.normal]

This is a strange one. I don't recall there being anything inside the bell housing area concerning the coolant system that is serviceable. I would hate to pull the engine unless I was 100% sure that is where the problem is. There are a lot of places it could leak above the transmission and both Chevy and DF did a good job of filling that are up with hoses and wires and such.

Does one of the bell housing bolts penetrate the water jacket on the block? I can't recall. If so, it would need sealer.
Could a leak in the oil cooler above the transmission allow water into the bell housing?

I have a spare LSJ in the corner. I'll take a look when I get home and see if something looks like a potential area to check.

Also, it's NOT polluting the oil? Strange! I don't believe there is a "serviceable" area into the water jacket behind the flywheel. The two plugs I see behind the flywheel are oil galley plugs, I'm guessing a hole caused by freezing or a stray bolt behind the flywheel forced into the water jacket. There is the outer wall of the water jacket behind cylinder 4, above the crank behind the flywheel, maybe block porosity or even a casting imperfection that finally blew out that happened to be behind the flywheel? I sure would like to see the final on this :mystery leak!

 

[PHENDERSON]

Started taking the engine apart. Pulled the valve cover off and there is coolant everywhere and a jelly like substance covering everything.

 

[escapepilot]

Jelly-like? Coolant under the valve cover is bad. Jelly-like may be really bad. GM’s factory coolant doesn’t mix well with other coolants. Mixing old-fashion green anti-freeze with GM’s can result in a jelled mess. I hope that isn’t what your jelly is.

 

[Gtstorey]

Jelly under the valve cover would be coolant and oil mixture.

 

[PHENDERSON]

Only gm dextron used. It's a hot mess. I'm about ready to take the good parts out and use the rest for target practice.

 

[escapepilot]

Glad its not the other...I've heard horror stories of incompatible fluids gunking up the cooling system.

 

[ah.b.normal]

Only gm dextron used. It's a hot mess. I'm about ready to take the good parts out and use the rest for target practice.

Not happy news there but mystery is solved. It’s all over but the cryin’.