Coolant leak at bellhousing after brand new GM Crate Motor install - SOLVED

[OR VietVet]

I don't believe I have heater hoses near the firewall. I replaced the 2 heater hoses (3/4" w/ plastic quick connect into the lower intake and the 5/8" at the water pump). I have a tahoe which doesn't have the rear heater like the suburban.

 

[YukonGTmaster]

Check the quick disconnect fitting for the heater line at the intake manifold, passenger side. I had one that wasn't seating anymore, and coolant was running all the way back along the rocker cover, down the back of the motor. Took me a long time to diagnose. Get the GM part, not the Dorman if possible.

 

[hank89]

View attachment 386896

View attachment 386897

My apologies. I thought someone was referring to heater hoses coming out of the back of the engine at the firewall.

Yes. I did replace the 3/4" and 5/8" heater hose lines that connect to the heater core at the firewall with new Gates Green stripe hoses. I also put on a new gm genuine heater valve (T). Unfortunately I put on a dorman quick connect...but I don't see any leaks there. All the heater stuff is new...except the heater core (original)...I pulled the carpet back thinking maybe I have a pin hole leak in the heater core...carpet is dry.

Will pressure test it when I get a chance this weekend. Thanks for all the help everyone !!!!

 

[neil_f_real]

+1 to what OR VietVet said. Since your block is new, perhaps one of the core plugs is not sealing properly?

I experienced a leak in the same location about 3 months after replacing my intake gaskets with FelPro gaskets. Thought perhaps I did a poor repair. It turned out that one of the two rear core (freeze) plugs was corroded and leaking. It was a transmission-out job to replace both core plugs.

 

[Summajet]

I would suggest renting the water coolant pressure testing kit from Oriellys, AutoZone, and advance. It would make it easier to see where the leak is coming from and not burn yourself on the hot exhaust or manifold. Pump it up to no greater than 15 lb psi.
It should help spot the leak quicker.

 

[HACK BLOCK]

just add dye to it

 

[hank89]

Just wanted to thank everyone that replied to this thread! The coolant leak was my dumbass fault! I just didn't connect the hose at the top of the waterpump! The new GM Crate Engine has been flawless and is great! I waited to post on it, just to be sure it wasn't leaking!!!

Thanks again everyone!

 

[willxfs]

Good to hear you are all squared away and thanks for following up.