View Full Version : Rust on bottom of exhaust manifolds????

12-04-2006, 02:37 PM
Does rust on the bottom of the exhaust manifold indicate anything in particular? I was thinking.....maybe slight salt water use??

I just bought the boat a few months back and the previous owner said he never used it in slat water, and the owner before him was from TN, so I don't think he did either.

Guess I'll hit it with the wire brush, some rust stopper, and some high temp paint.

12-04-2006, 02:40 PM
Happens on every boat. Mine is a freshwater boat with fresh water cooling and I still have it. Look at your exhaust headers on your car... chances are those are rusted too.

12-04-2006, 02:43 PM
yeah me to, over last winter i got some water in the boat and even had rust on the drive shaft and all over the pullies on the engine, a little sanding and that should fix your problem....thats my guess

east tx skier
12-04-2006, 02:48 PM
Same here and I've seen plenty others. Check your riser gaskets. If the look like burnt cheese, it's time for some new ones. As for what to do about it, the answer I received from my local boat mechanic(s) is "nothing; don't worry about it."

12-04-2006, 03:15 PM
ah yes. thanks for the reassuring news.

12-04-2006, 04:31 PM
The part oif the exhaust mainfold the bolt to the heads are not cooled by water and therefore rust after the paint has burnt off. It only takes a minute amount ot moisture to do it. It won't hurt anything and don't try to pait over it, as the heat will burn off and you will have smoke and stink inside thge motor cover till it burns off. The only way to cure it is to have them powdercoated with ceramic high heat powder like is used on race car, street car headers