Winterizing 496 Mag H.O.
 

Does anybody else have this powerplant in their Mariah? According to the manual, a few simple pumps from a bicycle-type air pump on a clearly located schrader valve clear all of the water out of the heat exchanger & manifolds (engine has closed cooling system). This seems fine & dandy, but I'm still a bit paranoid.... has anybody ever experienced problems with this? I'm going to stick some RV antifreeze in the raw water portion of the heat exchanger & manifolds just to be safe, but I'm interested to find out if anybody else does has had any issues..... seems way too easy (Especially for a boat!)

Thanks for your help.

Tvacek,
I have the 496HO. I have used the air pump at the end of the season during a brief cold period before my last fall run. I have never trusted it for the long term (google the price of a new or rebuilt 496HO :eek_animated:). The amount of water pushed out by air is not all that much, but it may be enough to allow the ice to expand and not crack the block.

On a side note, I didn't know the 496's were available on 2000 year models. I would say yours was built late in the year, because most 2000,s still had the 502's

You're right, his boat was made in November of 2000. :wink_thumbup: Could have been one of the first ones to be equipped with the 496!

Thanks for your help guys.

I went ahead and flushed some RV antifreeze through the heat exchanger & exhaust manifolds. Technically I shouldn't have to worry about the coolant in the engine block as its closed-cooling, but I went ahead and tested the dex-cool just to be safe.

Now all thats left is the fresh water, transom shower, and toilet.

Somebody wake me up when Spring gets here......:stick_poke: