Some progress tonight. I've had the passenger drain open for several days. It still had water in the water pump opening, so I dug around with a coat hanger. Got what seemed to be wet cement mix out at first, then what appeared to be mud. Finally the clean water that had been sitting on top of it.

Ran a gallon of water through both sides of the engine, from the water pump openings. The water out of the drains came out clean. Probably do one more on each side tonight just to be thorough, then maybe tomorrow start putting it back together. I still need several gaskets, an oil change, and a new starter.

They've had us on 14 hour shifts, seven days a week this past week, and probably for at least two more to come, or else I probably would have had this done by now. Oh well, the double time sure will come in handy!

 

I think it's fixed. Got it back together last night, and went for a half hour test drive. It never went over 183*, with the 180 thermostat I have in it. I'll want to drive it some more before I full trust it.

Right now I have straight water in it, I'll give it a few days and drain that and put anti freeze in.

 

Nice work!

 

I'm gonna call it fixed. I've drove it to work and back, plus around town for a couple days now, and it's never gotten above 189*, with a 180* thermostat. I did notice my new radiator cap is leaking, so I'll have to get another one of those. Also, I have no heat! And it's starting to get cold!

I have to drain the system, anyway, since I have straight water in it, so I'll try and flush out the heater core while I'm there.

I guess the moral to this story is, if you don't open the block drains, you aren't really flushing out the whole cooling system. Thanks to everyone who helped out and offered advice

 

Make sure you backflush (not forward flush) the heater core and not with over 15 psi of pressure. Would hate to see you have to do a heater core because of too much water pressure. If you can configure a pressure gauge in between a garden hose and your heater core outlet hose, then you can adjust the flow to get the desired pressure and no more. Think plastic gaden hose fittings at the hardware store. Easy does it, especially at first. Might cost a few $$$ to rig up, but you don't want to do the heater core without good reason. Also, I wouldn't use flush chemicals on an old heater core unless absolutely necessary to get flow (if 15psi backflush doesn't work then at that point you have nothing to lose)

 

Remembering back to the old brass radiator and heater core days, we used a Prestone Radiator Flush that really knocked out the calcium and lime from running tap or well water as a coolant. EPA and aluminum cores have eliminated that as a way to remove the lime. I've been successful unclogging a heater core in my second-hand 2000 by disconnecting both heater hoses at the engine ends and poring white vinegar into one of the hoses with a small funnel. 10-15 minutes and then back flushing will get a lot of the lime cleared out. I did a second treatment and then the water came out clear and with good flow. A glass full of water and four table spoons of baking soda neutralized the remaining vinegar in the heater core. Of course, the best cure is prevention........ always use distilled water instead of tap water in your radiators and batteries.


I did this because my core was 90% stopped up and a last ditch effort before replacing the core.... This may have been extreme and there may be better methods. I would be interested in learning what has been successful for others.