394 engine flush

[marinus_]

Good day Eh!

I was wondering if anyone would know the proper way to flush / clean out the cooling system for a 394 ci olds motor.
I had removed the intake and installed a new intake gasket and I noticed that the water jackets seemed to have a lot of sediment in the heads near the frost plugs. I removed the frost plugs and tried to clean as much as I could with my finger in the hole. I did get a lot of gunk out of there but I am sure that a lot of debris is still left in the engine.
The intake is re-installed and new frost plugs put in but I would like to flush the engine before I start it up and get the radiator and water pump blocked up.

I would appreciate any help you could give to an olds fan from the great white north.

[Lady72nRob71]

Does the block have drain plugs about on the same level as the freeze plugs? (Hex head like oil plugs.)
I pulled mine one at a time and forced water in with a garden hose through the heater outlet and the thermostat housing. I blocked everyplace else so the water HAD to come out the drain plugs. If you do not have the drain plugs, you can still force water in the same places and try to let it come out the opposite end of the block. (Hard to describe). Do you have a service manual that shows the coolant flow through the engine? That can help you decide where to direct the water. It will need to flow through at least several minutes each configuration to stir up the sediment and carry it off.
After doing this once, put it back together and use the Prestone super cleaner (not the flush) and follow the directions exactly. After your last drive, let it cool to 100* or below and immediately drain and flush it with the hose like you did earlier.
Do not forget to do the heater core also, but with a lower pressure on the hose.
Lastly put in your antifreeze and distilled water solution.
I did all this to my 350 and got a lot of crap out of it.

But you better do this soon before it gets cold up there! Trust me, you will get wet doing it this way...

[mugzilla]

Originally Posted by Lady72nRob71

.
After doing this once, put it back together and use the Prestone super cleaner (not the flush) and follow the directions exactly. After your last drive, let it cool to 100* or below and immediately drain and flush it with the hose like you did earlier.
Do not forget to do the heater core also, but with a lower pressure on the hose.
Lastly put in your antifreeze and distilled water solution.
I did all this to my 350 and got a lot of crap out of it.

But you better do this soon before it gets cold up there! Trust me, you will get wet doing it this way...

My Uncle uses 20 Mule Team Borax ...

Have you ever heard of that ..?

[Lady72nRob71]

Originally Posted by mugzilla

My Uncle uses 20 Mule Team Borax ...

Have you ever heard of that ..?

No, never heard of it used in cooling systems... I guess it just depends on what the active chemicals are. The borax is sodium borate, a very good general purpose cleaner - been around for years - for a good reason! I still use boraxo hand cleaner - works pretty good on grease and stuff.

The Prestone cleaner is sodium citrate, which is more of a food additive like citrus acid... Mmmm... -sounds almost good to drink!

-disclaimer:
Do not drink radiator cleaner no matter how good the ingredients sound!

When flushing the block, you may be surprised at what you wash out accidently!
http://www.flickr.com/photos/robsalbum/2575994434/
http://www.flickr.com/photos/robsalbum/2575994424/

[marinus_]

Thanks for the advice. I am hoping to do it this weekend (after I install a new lower element in the stove, a new kitchen sink and tap, cut the grass, clean out the shed blah blah blah...............)
Maybe next week.