I have mad a DISCOVERY!!-coolant leak from exhaust manifold bolt holes

-
7

75Dart440

Active Member
Joined
Feb 25, 2010
Messages
28
Reaction score
0
Location
Inver Grove Hts Minnesota
So I just assumed that on my 1971 440bb engine the coolant leak coming from the exhaust manifold bolt holes was because the holes are tapped into a water jacket...NOT THE CASE!!!! I used a video scope to look inside the bolt holes. I found this (see pictures) on the first and last bolt holes on both driver and passenger side....
View attachment exhaust manifold bolt hole1.JPG
View attachment exhaust manifold bolt hole2.JPG
View attachment exhaust manifold bolt hole3.JPG

The back of the bolt hole has rusted through allowing coolant to drain into the bolt hole and leak out around the bolt.
SO... then used the same tool to look inside my brand new aluminum radiator and found little rust flakes stuck in all the vanes inside the radiator!!! I cant just seal up the bolts and call it good because there is little rust flakes floating around the cooling system.

SO NOW WHAT?! BUY NEW HEADS?
 
I would seal up the bolts anyway. You are going to have rust flakes in any old car coolant system. As long as they aren't chunks of metal, they aren't going to do any damage. My small block bolts go into a water jacket, so they have to seal. It works on sb, why not bb?
 
Id flush the system and then just seal the bolts and call it good. No big deal. Think of the flakes they use in radiator stop leak. Those are big and plentiful flakes that do no harm. Id say youll be fine
 
Do you have enough threads to keep from stripping them out when the manifolds are put back on? If so seal it and forget it as the others have said.
 
I don't think the holes are rusted through. I think they are like every single other big AND small block Mopar engine head. Drilled through. Remember, the factory did crappy machine work at best. It would be just like them to barely drill the holes through. Every single factory head I have ever seen had the two end holes drilled through, so I don't think all of them rusted. They were made thataway.
 
StrokerScamp said:
I don't think the holes are rusted through. I think they are like every single other big AND small block Mopar engine head. Drilled through. Remember, the factory did crappy machine work at best. It would be just like them to barely drill the holes through. Every single factory head I have ever seen had the two end holes drilled through, so I don't think all of them rusted. They were made thataway.
Click to expand...


Exactly. My first Mopar and my 2nd Mopar were both only about 1-2 years old when I installed headers on the 69, and had the '70 apart, which already had headers. So two cars, both 1-2 years old. THEY LEAK coolant.
 
I recall my 440 having the same thing I studded and sealed the end bolts, which made it easier to line up the fender well headers anyhow. I don't think it is a real corrosion issue.
 
Prob just years of crud built up in the heads, unless they were recently baked and rebuilt, but still could be crud build up thats built up in the hole over the years.
 
Regular coolant changes can help prevent rust, too.
 
You must log in or register to reply here.
-

Back
Top