That amount of rust on an engine with closed cooling seems unusual. How long was the antifreeze in use? Almost looks like a lack of corrosion inhibitors. Here's what mine looked like when I pulled off the manifold, the orange stuff was the old gaskett that were stuck on like Kryptonite. This engine was 29 years old when I took it apart, raw water cooled, used in salt water 100% for 15+ years.
The antifreeze looked like it was recently changed. Prior to that I don't know. This was my first season with this boat. Obviously things have not turned out so well.
I have no explanation for all the rust on the top of the motor. Even if the rain gutters on the hatch were clogged , water would not drip on top of the motor.
Intake manifold is at the machine shop and will be magnafluxed and checked for warpage.
I sent out the injectors for cleaning and flow testing. All the injectors on the port side were out of spec prior to cleaning. all were OK after cleaning (within 2.5%).
Is there any cross reference list for Mercruiser to GM marine engine part numbers? I have not been able to find much.
While I had the throttle body off, I was going to replace the gasket, until I saw the price. After much searching I was able to determine that the throttle body was used on a 2000-2002 Cadillac Seville 4.2L . Price for the gasket was $15, less than 1/4 the price that one of the online Mercruiser dealers wanted for the part.
