Exhaust manifold gasket leaking . . . Again!

[kaliona]

1978 I6 165hp mercruiser. I have another exhaust manifold leak. I had a shop change the gasket to fix the last leak only 120 hours ago. I'm going to try and change it myself this time to save some money and time (shop is booked til May). seems to me that last gasket failed too soon. What could have caused this failure? Improper installation? Is this a sign of the engine running hot? Looks like a simple fix. Any tips from those that have done this before is welcomed and appreciated

 

[Bondo]

Ayuh,.... The gasket between the manifold, 'n head,..?? or manifold, 'n riser,..??

 

[kaliona]

It's the gasket between the manifold and the head.

 

[alldodge]

It's the gasket between the manifold and the head.

The gasket would normally not leak, since it is my first thought is the matting surfaces are not flat. Remove the manifold and check for flatness and corrosion with a steel straight edge. It's not hard to remove just takes some time. My guess is you may be need to replace the manifold