removing knock sensor before removing block plug

[gt2003]

I believe this is the knock sensor. I was able to disconnect the wires/connector that go to it. Is there anything special about removing it? It looks like its just a simple deep well socket or box wrench. It's the 1st time to winterize an inboard so thought I'd check before I start.

 

My plan is to warm the engine, drain the block, blow out the heater, unhook the water intake hose from the block, replace with a shorter piece of hose which will run to a large bucket of antifreeze, start the motor and let antifreeze run into the system. Similar to what I did for my I/O but insteah of using muffs I'll use the bucket/antifreeze. Will be fogging the motor, changing oil and transmission fluid during the process. Thanks folks

 

 

[MNshortliner]

Yes knock sensor. Don’t forget to pull the plugs in the exhaust manifolds and drain the water in those.

[gt2003]

Thanks @MNshortliner , do I just unscrew it like I mentioned, nothing special? Yes, 4 plugs total!

 

Anyone heard of "draining the mufflers"? I saw if on a youtube video for a V-drive but I've never heard of it otherwise. Looks like on his boat it's just a small screw underneath and towards the rear of one of his mufflers. Like I said, I've never heard of it but it never hurts to ask. Thanks

[powbmps]

Make sure you stick a screwdriver up into the hole the knock sensor came out of (and the hole on the opposite side of the block). Rust fragments can block them up, making you think the water is drained, when it actually isn't.

[MNshortliner]

Yea just unscrew it I think 7/8”. If it spins and does not come out you will have to use a large channel lock pliers on the big round outside. Do not overtighten when putting back in. Not sure about draining muffler. They are kind of self draining but when you fire it up to suck in antifreeze they will blow out water. I use about 3 1/2 gallons antifreeze and about 1/2 gallon comes out exhaust

[dvskier]

Also drain the transmission cooler and J tube (attached to raw water pump). If you have a heater and shower those must be drained too. Empty raw water strainer and you're done.

[h2onhk]

Is your Malibu fuel injected? Can't remember if the '96 was or not. If so I would fog it by removing accessory belt, pulling spark plugs, spraying fogging oil inside each cylinder and rotating the flywheel by hand a couple of times. Supposed to be more friendly on the injectors than having the oil coming in contact and potentially fowl them.

[Chef23]

I use a big pair of channel lock pliers and just grab the large round part. An open end wrench will work it shouldn't be in there very tight.

 

I have a 2002 Response with FI. To fog it I just spray fogging oil in the intake on the top. We have been doing this since it was new and it has been great. I don't have a heater so I don't pump antifreeze into the block I just store it dry. In 02 when we bought the boat that was the recommendation from Malibu and the dealer. Given you have the heater I would definitely run antifreeze through it.

 

 

[disland]

winterizing in October, how sad :'( :'(

[UWSkier]

Agree on the large Channel-Lock to remove. If you put a wrench on the hex head, you're likely to just round it off. It's pretty soft, the corners are not well-defined when new, and those sensors can be sticky.

 

Agree with @Chef23 on the steps also. Been winterizing my dad's '01 for going on 18 years now and never put anti-freeze in the block (but do blow some through the heater core). Boat has been in temps below -20F and no issues.

[adkh2oskier]

on my 09 Nautique I found that channel locks were not usable, to tight to get in to take the sensor off. Found that a 22mm wrench worked perfectly.

[powbmps]

I use an 02 sensor socket on mine.

[BraceMaker]

22mm 6 point deep well socket is the ticket. PUSH inwards before you turn it as there is a bit of a taper on the metal. 7/8ths is the common substitute but it is slightly larger and you will be at risk of rounding the sender.