wheres the engine block drain, 4 coolant?

[corelokt]

I'm getting ready to install the new thermostat, and block heater. I'd like to drain the block of it's coolant while I do it. Where is the plug to drain the block?
As long as I'm picking brains here, where do you tap into for engine oil temp? Is there a spot near the filter?

 

[ida34]

The block does not have a drain but there is one on the radiator at the bottom. I can't remember is if it is the driver's side or passenger's side but it will be on the engine side of the radiator near the bottom but not on the bottom. This will drain the block enough to install a heater. Are you putting in a freeze plug style heater? You might have a little dribble out of the block but not a lot if you have drained the radiator. As for the oil temp I am not sure. You might make a t at the oil pressure sensor but I wonder how accurate the temp reading would be if it was not directly in the block.

 

[corelokt]

Ah, the heater said to install the return line into the block drain. Maybe I'll just use the lower radiator hose heater I also have.

 

[ida34]

Do you have a coolant heater or a block heater?

 

[hobie237]

Are the drains on these radiators plastic or metal? I ask because it's too cold out for me to check, and I'm not home.

Anyway, if it's plastic, I wouldn't touch it. Those things get brittle with time, and can often suffer damage when being removed, and then you're in trouble. I find it's usually MUCH easier and safer to pull a lower radiator hose. Messier, but safer, and with a big pan, it's not really a big deal.

Then I'd pull an upper radiator hose and run a garden hose through the engine. That should flush out whatever crud is in there. Repeat for the radiator.

Yeah, the hoses may suffer damage in the process, but if they do, they should be replaced anyway, so it's a moot point. If concerned, one can always slit the hose at the connection lengthwise and peel away.

 

[ida34]

They are metal petcocks.

 

[hobie237]

Hm, for some reason I thought they were plastic, but I really don't remember. Then again, my radiator was replaced in 2007, so it may not be original type, model, etc.

 

[CUCVFAN]

The block does have drains along the bottom edge on each side above the oil pan. There's a pipe plug on each side, but the problem is getting to them. One is probably behind the motor mount, and the other might be just as hard to reach. If you get them out, you'll probably have to poke an awl in there to break up the crud and let the antifreeze flow out.

 

[CUCVFAN]

Forgot about the oil temp. There's a pipe plug above the oil filter that can be used to get the oil temp (it is used by the Banks turbo kit as a supply for the turbo).

 

[ida34]

I used to work at a radiator shop in the 80's. All of the GM truck radiators were metal. That is for the full size. This is when the cores were soldered to the tanks. Newer radiators have plastic tanks pressed onto the cores. Bent fingers hold the tanks on. Most of the time the radiator is aluminum with a plastic tank. These are the ones with the plastic petcock. If they break it is a real problem. If the metal petcock wingnut comes off you can still remove the petcock and replace it. The plastic ones are replaceable but you have to get them out first.

 

[ida34]

The block does have drains along the bottom edge on each side above the oil pan. There's a pipe plug on each side, but the problem is getting to them. One is probably behind the motor mount, and the other might be just as hard to reach. If you get them out, you'll probably have to poke an awl in there to break up the crud and let the antifreeze flow out.

Those are not really drains. They are access ports to clean out the block during a rebuild. He may be able to use them for that purpose though. This may be what they wanted. I would think they are way to small to circulate any appreciable amount of coolant. I think he had a heater hose style coolant heater not a block heater. If this is the case I think they want it mounted to the return side heater hose.

 

[lindyp38]

to open that pet cock......do i turn counterclockwise......?

i didnt wanna force it anymore than necessary......

thanks