View Full Version : Northstar 4.6 - coolant comes out rear exhaust manifold bolt hole

12-26-06, 09:46 AM
I am in the process of putting headers on a 1996 Northstar (it's in a sand rail) and had coolant come out when I removed the exhaust manifold studs.

Is this normal?

12-26-06, 10:48 AM
I don't think that's normal. I guess it's possible one of the holes was drilled too far into the cooling jacket or something, but I don't know. Is it just one hole, or all of them? 100% sure it's coolant?

12-26-06, 11:35 AM
No, it's not normal. Do a cylinder pressure test. The only way I can think of coolant getting into the exhaust ports is from a head gasket.

12-26-06, 09:28 PM
The cooland came out of two cylinders (two bolts) and it wasn't a drip or two. It was a pretty steady stream.

It seems strange that it didn't smoke at all prior to my doing the exhaust work.

12-27-06, 02:24 PM
^^ No smoke, but did you notice any change in coolant level before you started to change the headers?

12-27-06, 06:13 PM
No, there was no change in the coolant level.

12-27-06, 09:03 PM
I think you should start it up without those bolts to see if it starts peeing

Might just be a hairline crack somewhere or a casting flaw.

12-27-06, 10:06 PM
No, there was no change in the coolant level.

:hmm: That's why I asked. I don't think its bad head gaskets then...though I could be mistaken.