Stickies on Winterizing 3.0 cobra

[Randy stoner]

I have been all over this forum and I know its right in front of me but im trying to find the proper proceedure to winterize a brand new 3.0 cobra 4 cylinder (Chev 140 hp).

randy

 

[Grub54891]

Drain the block, and exhaust/intake manifold. If you have power steering be sure to drain the heat exchanger. Before I forget, do you have closed cooling? If so you don't need to drain the block. If you want run non toxic anti freeze through the motor.

 

[Randy stoner]

Its not a closed system. There is a petcock on the manifold on the port side. What other places do i drain and do i add antifreeze into all the hoses?

 

[Scott Danforth]

drain the block, drain the manifold, pull the large hose and drain that

if you want to add antifreeze, use a funnel at the thermostat housing after draining.

 

[Randy stoner]

I know where the manifold drain is but not the block drain. Where is it on a 3.0?

thanks
randy

 

[Lou C]

OMC used a brass drain valve that you should be able to find. In addition to the drain on the exhaust manifold and on the engine you have to disconnect the bottom end of the big hose connecting the front water pump to the thermostat housing. There are 3 plugs on the pivot housing you have to tilt up to see 2 of them. Pike the holes and put the drive down to see if water drains. When done replace the 3 plugs. Then you disconnect the raw water intake hose from the thermostat housing and hold it down in the bilge to drain any remaining water. Now put the outdrive down and hold that hose up & fill it with -100 marine AF till it runs out the outdrive water intakes. That will push any remaining water out of the transom hoses and p/s cooler if you have P/S. These are actually pretty easy to do; easier than the V8 or V6.

 

[Lou C]

 

[Randy stoner]

Lou, the pic you supplied looks different from what I have. My manifold is on the other side (3.0 chev 4 cyl).

randy

 

[Randy stoner]

Is RV watersystem antifreeze any good for winterizing the block

 

[Scott Danforth]

I know where the manifold drain is but not the block drain. Where is it on a 3.0?

thanks
randy

about 3/4" above the oil pan rail, mid block under the manifold. it will simply be a 1/4" pipe plug

 

[Grub54891]

Is RV watersystem antifreeze any good for winterizing the block

Yes, but get the-100 stuff, blue in color.

 

[Lou C]

Lou, the pic you supplied looks different from what I have. My manifold is on the other side (3.0 chev 4 cyl).

randy

Looking back I posted the wrong pic, that's the 2.3 liter Ford! Sorry for the mix up. I don't have a pic of the 3.0 GM engine.

 

[Lou C]

Is RV watersystem antifreeze any good for winterizing the block

Not if it does not have corrosion inhibitors

 

[hugh g]

I used pre mix AF available at any auto parts store or you can mix your own but makes sure it's at least 50/50 that will protect your engine down to -25 or so.

Fog the engine until it stalls, then drain the block & manifold.
Don't leave any standing water in the bilge.

 

[Randy stoner]

I found the drain on the manifold and the block and they are free and clear. I contacted a local marina to see if they would winterize this and they said yes but they do not have a lot of experience with OMC. They said they have an adapter to connect to muffs. Given the waterpumps are so high up on the outdrive, how good is this set up they are talking about? Ive seen some on line and its a device that you run the motor till ist warm to get the thermostat open then close the water and open the valve for antifreeze. Gravity and siphon brings it in but any vid ive seen, there is a $hit load of steam coming out and that can NOT be good. To me the position high up of the OMC waterpump is detrimental to it cooling well unless the outdrive is in the water or you have a lot of pressure on the muffs. I have never seen a lot of water come out of mine when running on muffs so im leary about sending this to someone else. This is a brand new motor and i dont want to over heat it.

Should i just drain the block and manifold, undo the hoses and pour antifreese in all of them till they over flow and call it a day?

Randy

PS This is the second new motor i have had in this boat in one year. Warranty covered it though. The first had either a cracked head or blown gasket and i lost most of the summer. I dont want to go through this again.

 

[Scott Danforth]

Ive seen some on line and its a device that you run the motor till ist warm to get the thermostat open then close the water and open the valve for antifreeze. Gravity and siphon brings it in but any vid ive seen, there is a $hit load of steam coming out and that can NOT be good.

first, as soon as the thermostat opens, it closes, so all the anti-freeze in the block-buster 2000 kits or the scam-co kits simply goes out the transom

the OMC has the water pump at the same height (crank centerline) as Volvo Pentas and the Mercruiser Bravo's

drain all the water as indicated in post #4

then add antifreeze if you want via a funnel to the hoses

Should i just drain the block and manifold, undo the hoses and pour antifreese in all of them till they over flow and call it a day?

yes, and drain the big hose too prior to pouring AF.

 

[Lou C]

That’s how I’ve done it for nearly 20 years.

 

[Grub54891]

We put a pump on the hose for the muffs, after draining the block/manifolds/coolers. It pushes the anti freeze in instead of depending on the impeller to suck it up. Run till it comes out the exhaust and done. I know, water always comes out the exhaust bypassing the block, We run about 5 gallons through though, block is full.

 

[Lou C]

If you are going to use that method, I suggest loosening a drain plug take a sample and put it in the freezer to make sure it won't freeze.
I do think the antifreeze helps because when I start my engin up in the spring I do not get rusty water coming out of the exhaust.

 

[Grub54891]

If you are going to use that method, I suggest loosening a drain plug take a sample and put it in the freezer to make sure it won't freeze.
I do think the antifreeze helps because when I start my engin up in the spring I do not get rusty water coming out of the exhaust.

Neither do I. It's -100 rv anti freeze.