I meant in relation to the cooling system. Did you pop off the water pump to see what condition the impeller was in? I just have a feeling you'll be seeing some problems with that cooling system in the near future. Flushing only helps so much. I would have replaced every piece of it if it were me

 

I'll drive it on highway for 30 min and that is it, if everything is OK.
I used about 1 lb. of bolts to clean coolant bottle. Bottle hose was clogged.
I suspect radiator is partially clogged.

 

I suspect most everything is at least partially clogged. That same corrosion is inside all hoses, radiator, caked on the water pump, everything man. You have the very delicate cylinder head. And if you overheat it, that could be the end of it. So you need to be as careful as you possibly can. If you're going the cheap route, you at the VERY least need to pull every component apart and THOROUGLY clean it. Although I highly suggest replacing it all.

 

Glad it's running. Good work!

What did you pay?
It couldn't have been THAT much, considering it wasn't even running.

Mileage?

 

maybe I'll do marine engine acid flushing:
http://www.moyermarine.com/forums/showthread.php?t=127

 

Acid flush? What effects would this have on gaskets and metals in the radiator?

 

Just remove the rad, pump, what's left of the stat. Stick a garden hose in the the stat hole in the head and let crud flush out thru the pump hole in the block. Use the garden hose to flush the heater core thru the hoses. Install new parts (rad, stat and pump)and fill with fresh 50/50. Check the color of the coolant in the rad frequently (motor COLD). At the 1st sign of coolant color changing, drain and refill with fresh. The coolant will remain greener/cleaner longer after each refill. To do a drain/refill with fresh coolant takes about 15 mins.

 

Before I did that I'd use CLR and flush the heck out of it afterwards. But since your system seems to be operating basically OK, you don't need a Hail Mary play to save it- I'd use neither (not worth the risk to the aluminum). DJB's suggestion will work fine, or you could Grab Part # 19286424 from your local GM dealer, the GM radiator flush. They use it to clear out the Dexcool messes. While not as aggressive as the old two-part GM cleaner, it's still better than most off the shelf parts store stuff, and won't harm any aluminum.

 

The reason I'm suggesting disassembling the cooling system, then flushing, is to prevent clumpy crud from being flushed from one place to another. The block/head have the largest coolant passages, therefore the block/head will have the largest clumps of crud. It will be best to flush the big crap into a bucket, not throughout the cooling system. FWIW, the CLR site says "do not use in a radiator".....if it's not recommended in a radiator, it's probably not recommended circulating throughout the motor and heater core either.

 

Absolutely agree. Also FWIW CLR shouldn't be used on aluminum and most radiators are aluminum... if one were to use it on JUST the block though the cast iron I don't think would mind that much; can't really speak for the head gasket, water pump, or various sensors, however. (Not an expert but felt that needed mentioning)

 

I run clr through my coffee maker, dish washer and clothes washer regularly. I also ran it through a car I purchased with an aluminum head no less and had no noticeable Ill effects. The cooling system looked much like yours. I didn't replace a single component. I do not own the car anymore so I can't comment on long term as I only owned it a year.

 

However, I guarantee whatever car you had, didn't have a fragile head like his. So he needs to be extra cautious or he could be looking at replacing the head in the near future. Replacing every component of the cooling system would cost you around $200 and will give you great assurance that you won't need be ripping apart the engine very soon

 

That why I referred to it as a hail mary, which the OP doesn't need. You use it when the alternative is to scrap the block. I brought it up because OP was considering using muriatic acid.....CLR is the better choice of the two.
What he's got the GM cleaner will work fine.

I've used CLR on aluminum, most recently a clogged up Northstar I bought cheap. How do people not notice when the water pump idler self-destructs and they're running in limp? Anyhow, there's an aluminum head AND block there, lol. If you leave CLR in there it's going to come back and bite you. If you flush it all back out, it simply does it's job.

Those coffee pots they do recommend CLR be used in contain aluminum too...the heater coils. Of course coffee pots cost $10, nobody sues over them and they get rinsed out pretty quickly. I'd recommend against use in radiators too were I the manufacturer. Not worth the additional sales, putting up with the clowns who leave it in, rot their system, then call 1-800-rentalawyer.
There's a reason you can't buy really good radiator cleaner anymore. The reason is some folks don't know the difference between a cleaner and an additive, but they do know their lawyer's phone number. Now they sell you $6 lemon juice. Doesn't work but it won't wreck anything either.

 

forget about this !!!!! Buy a new one today !!!!!

 

Really? What internal ill effects would u expect to see externally? Why would CLR say "do not use in a radiator"? Maybe something to do internal ill effects? I guess it would be ok to to use in a vehicle one is going to get rid of in a year. LOL