Leaking exhaust threads

[88_AHB]

Hey everyone,
Wondering if any of you have come across this issue.I recently fired up my rebuilt 318 and the front and rear exhaust (header) bolts were leaking coolant from around the threads? I wasn't aware that dodge runs these into the water jackets? I'm gonna pull all 4 or 8 bolts out tomorrow and either use thread sealant or rtv. Is this a common occurrence or is there something wrong?This is my first dodge,i've have been a GM for a long time and never had this issue with them.

 

[7T8 Custom]

Yes, those bolts run into the water jacket. Normally you use a stud for those holes.

 

[88_AHB]

Is this for the very outer corners (4) or all 8?

 

[7T8 Custom]

Just the outer 4 corners.

 

[SixBanger]

I would not use RTV as a thread seal. Use Permatex High Temperature Thread Sealant or Hylomar Universal Blue Pipe & Thread Sealant.
Hylomar can also be used to gas-tightly seal inlets or crankcase halves of a two-stroke engine block. It does not require a gap as an RTV and remains thorny over time.

Permatex High Temperature Thread Sealant at Tractor Supply Co.

Hylomar 31654-AA Universal Blue Pipe & Thread Sealant Gel for Jointing. 100 g | eBay

 

[Aspen500]

This stuff works excellent for sealing threads also.
Permatex Thread Sealant with PTFE 80632

 

[88_AHB]

Thanks everyone, never have seen something like this happen. I’ll give it a go later today.

 

[AJ/FormS]

Be careful to not overtorque those fasteners. If they break, after they are locked in there, you'll be extremely irate at all the trouble that mistake is gonna cause.
If I have to remove those corner studs to install the headers, I always put the studs back in there, with no sealer. I double-nut the buggers, torque them in there against their shoulders,and remove the nuts.Then I put a drop or two of thread locker on the shoulder right next to the head and let it wick in. Finally, I use the slanty conical washers and usually brass nuts. I doubt anyone could ever overtighten those brass nuts to break the studs,lol.
On one occasion I slotted the rearmost holes down thru the flanges, because I was afraid getting the studs out would be impossible without breaking them. Those special slanty washers came to the rescue, and bridged the slots.
Some say those brass nuts come loose by themselves.
I say; get a better gasket.
The gaskets that came with my TTIs were fabulous. Nothing ever came loose. After about 5 or 6 reuses, they finally wore out. I cannot recall what brand I replaced them with, but they must be good,cuz they've been on my 367 since 2004,IIRC. I remember I got them from Jegs, not house-brand tho.

 

[88_AHB]

Curious what’s the advantage or disadvantages of using a stud vs bolt for the 4 corners?

 

[volare 77]

The stud seals better against antifreeze leakage than a bolt because of the shoulder. If the stud makes it hard to install the headers then either cut them a little shorter or leave them out until you get the header in place. I like the studs because it helps with keeping the gasket in place when installing headers and a place to hang the headers while trying to install the rest of the bolts. The problem with stock heads is many times the studs are rusted in place and can be a bear to get out without damage.

 

[Oldiron440]

On my big blocks I've been able to retain all the studs with the exception of two on each side do to length and interference with the headers. I much prefer the studs over bolts.

 

[88_AHB]

I put all bolts in and used the high temp sealant. No leaks so far... Perhaps I should switch out for studs instead now to make sure I’m good for later.

 

[volare 77]

Only the four end holes on a small block have coolant. As long as the bolts don`t loosen you should be ok.

 

[88_AHB]

I know this now, just meant i'm second guessing on those 4 with bolts in instead of studs lol!