Exhaust Water Leak

[bigal]

I have replaced my manifold this year on a RWC A4 with a good used manifold (I hope). I have started and run the engine, found a few leaks, most of which were pipe threads not tight enough and hose clamps needing tightening. One small leak that I can't stop seems to be originating at the flange to the hot exhaust section. Is there a possibility that the tap for the top stud for the exhaust flange (I installed studs) is open to the water jacket and water is finding it's way out through that path? I did use Loctite threadsealer on those studs.

[Marian Claire]

This may help, http://www.moyermarine.com/forums/sh...exhaust+flange Sounds like some manifolds do have holes into the water/coolant area.
Dan S/V Marian Claire
Edit: Just found this http://www.moyermarine.com/forums/sh...exhaust+flange Check out the 13th post from Don Moyer.

[ghaegele]

This happened today. I recently removed and replaced the manifold and thought I had a leak at the flange gasket. turns out the hot side water hose clamp needed a little tightening. It drips right on to the manifold at the studs.

[bigal]

The news is worse than I thought. The #4 plug is fouling with water, the oil has water in it. I hope it's only the head gasket.

[bigal]

This may turn into a rebuild topic, but I pulled the head and in the process damaged the head gaskets so bad I couldn't tell whether they were damaged prior to removal. There appears to be water in #3 and #4, but #4 had so much water the plug became fouled with water. I'll have the head checked, but we had it off a few years ago and it seemed find, but will check anyway. I'm going to pressure test the manifold, which I took off the block, with town water pressure. I believe I can check the block once the head is on, possibly with air as I heard described in a post somewhere in the forums, maybe town water pressure.

[bigal]

Just a status report; I have the head at a machine shop to magna-flux and plane the head. I now believe the manifold is suspect, this is a used manifold that looked good, but I didn't pressure test before assembling. I hope that no damage has been done to the block.

[ndutton]

Do you have compression figures before the head removal? If so, please test compression after you get her back together. I'm curious about the effect of planing (milling) the head on compression.

Good luck.

[bigal]

I will be sure to check compression after re-assembling. I was so pissed off that I missed the water intrusion in the cylinders for so long, luckily it is freshwater as we are still on the hard. I just pulled the head without thinking, assuming the gasket was compromised. Machine shop just called to say that the head is rotted through to the outside, so this may be the smoking gun. I guess I have to suspect the block also.

[bigal]

Got the head back and the spot on the head that is bad looks like the result of a porous casting, as the area around it is not rusted and the wall at the broken through spot shows a significant wall thickness around it. Furthermore this is a problem unrelated to the water entering the cylinder as it is in a different area and is a break through the outer water jacket. The head does not show any cracks through to the combustion chamber. Will JB Weld patch a hole through the outer water jacket or do I need to get a new head?

[bigal]

Checked the manifold by plugging a 1/2 inch water hose attached to one of the coolant barbed fittings and blowing into a hose connected to the other fitting to discover that the manifold has developed a leak at the #4 cylinder, explaining the water in that cylinder. I guess we'll be buying a head and a manifold and hoping no other damage was done. I don't believe the engine ran for an hour total with this problem using freshwater.