coolant leaking out of head by exhaust manifold

[troy.70R/T]

Well was working on some vacuum issues but now I see I have coolant leaking out of the passenger side head. IT Is leaking at the front of the engine. it looks like it is coming out around where the two front exhaust manifold studs go into the heads. This is a freshly rebuilt 440 so I am hoping it is not a cracked head. thete is no coolant in the oil and no white smoke when it is running. Is this a common problem for a 440. Also do those exhaust studs go into a water jacket?.

[Ghoste]

The exhaust studs do indeed go into the water jacket and this would be my first guess.

[troy.70R/T]

Thanks Ghoste. I know now I will NEVER rebuild another engine untill I build a test stand to fire it up on.

[Just 6T9 CHGR]

Like Ghoste said the studs are "wet" with coolant.    Pipe thread sealant is required on the studs when they go into the head

[troy.70R/T]

Will that withstand the heat. I think I used the copper gasket maker. good to 700 degrees.  what s stupid design.

[Ghoste]

I don't really think of it as a poor design myself but it is one of the things you need to be aware of with a big block Mopar.  The sealant will take it, there are some high temp ones out there.

[flyinlow]

Eddy heads are sealed ,but they where designed for use with header bolts from the start. I always wondered about putting short allen head screws in first with sealant and then the correct length header bolt on top ?


My son was replacing his old rusty headers with new coated ones on  his Charger. I had gotten use to the aftermarket heads and forgot about draining the coolant first on stock heads. He comes up to me soaked in antifreeze , all upset because he thought he cracked the head.   

[firefighter3931]

Permatex "Ultra Copper" high temp silicone works great as a ex stud sealant. 

Let the RTV set up overnight before re-filling the cooling system and you're good to go. 

My son was replacing his old rusty headers with new coated ones on  his Charger. I had gotten use to the aftermarket heads and forgot about draining the coolant first on stock heads. He comes up to me soaked in antifreeze , all upset because he thought he cracked the head.   

Hey Craig.....I think we all have the same reaction the first time we install new exhaust on factory heads, not knowing that the holes are wet ! 



Ron

[troy.70R/T]

Thanks guys. I unscrewed one from a spare head and sure enough right into a water jacket.