For the temp readings, I'm going off the gauge, plus my scanner. Guage is pretty much right on with the scanner. I also stuck a thermometer in the radiator just to compare.

Haven't done block drains. Honestly never though of it. I don't even know where to find them. Off to search!

I also started the exhaust manifold bolt pb blaster soak, just in case...

Edit:
just got the starter dropped, and passenger drain opened. Got nothing out of it, even though there's water still in the water pump holes. Now to figure out how to get to the driver side. If not for the front axle, it wouldn't be too bad

Edit 2:
Driver side drain open. There's water just below the level of the water pump holes, but I can't get anything out of the drains. Apparently I've got some blockages

Edit 3:
Is there two plugs on the driver side? I get a little oil out of the one I opened over there. Then I noticed another identical looking plug right behind the oil cooler line. That is impossible to get to without some super low profile socket.

 

You're getting beyond my experience. Don't clog up your new radiator. Maybe one of or master mechanics can chime in with some more detailed help.
I'm thinking if you cracked your manifold, it got hot, real hot.
I would get those water passages clean before you fowl up your new radiator, maybe through the freeze plugs? Check the debris you're pulling out to see what it is. Gasket material? Rust? Rocks? .......

 

I got nuthin,

 

So, still working on getting the driver side drain opened. No matter what kind of tools I used, I could NOT get to it. My choices were pulling the exhaust manifold, or oil cooler lines. Since I've had those oil lines off twice and they were a royal PITA, I decided to do the manifold.

Soaked it in pb blaster every night for a couple days, and tonight I got it unbolted. Only broke two studs, so I'll call it a win!

Can almost slide it out, but the knock sensor is in the way. (which conveniently takes the same socket as an O2 sensor. Good job, GM) Couldn't budge it, even with a break over bar! So it got the pb blaster bath, too, and maybe tomorrow it'll give it up.

 

Wow !! Hang In There !! I didn't have the time to repair my leak and the shop said they found tons of junk in all the passages from a previous owner.


I had seen stuff floating around in the catch tank and on the radiator cap when I checked coolant levels. Looked like ground up bits of walnut shell ( ?? ) .


I've now got more that half of what I paid for the truck in leak repairs ( sigh )


But its a keeper for a backup to my daughter's car which is beyond hope.

 

Doc - what you had in the system was prob a stop leak, some have ground up shells, metal bits ect. I've even had vehicles come into my shop that has been filled with pepper

 

Ground up shells and metal bits? Sounds like great stuff to pour into the cooling system! Mine didn't have anything like that, just the normal rust/old dex cool looking chunks of crap.

I'm just glad I can do all my own work, and only paid $400 for the truck. If it had cost more, or I had to pay a shop to do all the crap I've fixed on it, it would have been on Craigslist years ago!

 

So, a little progress tonight. First, it turns out the knock sensor is not a 7/8 like I previously thought. Don't know what it is. Smaller than a 7/8", bigger than 3/4" and 18mm, though, the closest wrench sizes I have.

But, it turns out you can remove the drivers exhaust manifold from th engine compartment with the sensor in place. You have to pull all the plugs, the temp sensor, and remove the heat shield. Disco the steering shaft. Now, hold your face a certain way, curse a lot, and you can twist and turn it out.

So now I can actually get a 9/16" on the block drain and open it. At first, nothing came out. Poked at it with a wire coat hanger, started getting a little stream of straight water. Poked some more, and the nastiest, most crappy looking orange dex cool comes pouring out.

Tomorrow I'll pour water through the top end, and poke at it till it comes out clean on both sides. With any luck, once it's back together, maybe she won't overheat.

 

Well you are making head way - If you have the intake back on I would put the spark plugs back in so no water enters the cyl and flush with a garden hose from one drain port to the other and vice versa and thu heater hoses into engine ect. just about any way I could put water pressure thu engine too help vacate it all out - 10 to one the good ol dex has turned to sludge thu out engine

 

That's pretty much my plan. I still have the intake off right now. I'm going to pour water into the coolant ports in the head until it comes out clean from the drain. Probably put some compressed air into the drains as well.

I was wanting to run the engine with the drains open, and just keep a steady water supply going into it, but it's impossible to get to them without taking off the starter and driver exhaust manifold.