Just drained my motor....

[joedirt00]

I just drained my motor and exhaust manifold on my 3.0 merc with 12 hours on it. The block drained clear water but the exhaust manifold was Black as can be . Is it normal to have this much sediment in the exhaust manifold? It has been sitting for about 6 weeks, but why was the block clear and the exhaust manidfold dirty?

[tommyadrian5]

both mine come out dirty, it has to do with sediment from your river/lake getting stuck in there, also has to do with the location of the drains and where the sediment settles, ie could have settled right at the manifold drain intake yet away from the block intake. also, from personal experience, the drain hose on the manifolds is much larger than the plugs on the block, and the quicker flow from the manifolds probably stirs up more sediment than the slow drain of the block.

tom