I got my head gaskets done and I was sure to torque everything down as directed. After the engine warmed up I noticed coolant pouring out the back in the front. Looking on top I noticed the front Bolt for the lower intake on the passenger side was hissing and cooling was coming out of it or possibly dripping from the black metal pipe above and then bubbling up from the pressure escaping out of that bolt. Any idea what could be causing this?
I'm linking a video I took to show.
https://youtube.com/shorts/HNr53aKP-Hk?si=8EsG8NiROMi4zUI_

 

At first I thought I improperly put the new head gaskets in so it was pressurizing the inside of the engine with coolant but while it was hissing I took the oil cap off and it wasn't pressurized at all and the hissing continued

 

I would say the Heater Hose Metal Pipe O-Ring isn't sealed and is leaking.

 

I second the o-ring being the culprit of the coolant leak. It can get pinched and leak in that spot, drip down the valley pan and run off the back of the motor and it looks like it’s leaking from the back of the passenger side head.

I’ve never encountered the hissing and bubbling though.

 

Did you solve this? I’m having a very similar leak. Just replaced the O ring on the heater hose and didn’t make a difference.

 

Hi temp RTV, the o-ring seal can be marginal. RTV on the outside surface NOT the O-ring. Let sit at least 24 hours.

 

Before deleting the throttle body heater, I'd find coolant down there whenever one of those hoses leaked. I agree with the others and think it's the o-ring on the metal tube (mine has leaked there before too) but don't rule out anything above that area where coolant flows.

 

I have never had throttle body leaks before, and don't see any coolant round that area but it is something I'm keeping an eye one. Just to make sure I'm nit missing something, the only way coolant could pool in the front of the lower intake is the heater hose, or throttle body right? I can't think of anywhere else right there. I replaced the O-ring but after cranking the truck again some more coolant did eventually dump off the back of the block, however I am unsure if that was excess coolant that was already up there, or it was more than had leaked out from before and just not fallen off the back yet. The truck hasn't moved yet, so there's definitely still some pooled up there from before the o ring. But I do recall still hearing small hiss from somewhere around there so I made have to just RTV that thing up. Any other ideas? Really really trying to have it sorted ASAP so I can make it Uwharrie this coming weekend with my club.

 

Really? Jeez, I think I must have gone through three or four new TBH kits over ~60K miles. Good for you then! haha.

Are you confident you properly torqued all the fasteners that you removed?

 

I think so, but it has been a little while since I had finished putting it all back together after the HG. I was waiting cause I still needed a water pump, radiator, and hose so its been probably a month since I was in there. But I had the rave pulled up when I did it and have a torque wrench so I would be surprised if I missed something.

And yeah, I have been lucky with my TB heater lol. Original components with 185k miles, hopefully it will keep going.