O/T Chevy s-10 Overheating Update

So I drained the radiator of the dexcool, flushed several times with water. Then filled with water, ran till it came to temp then drained and repeated. About 3 times. Drained it all again put a new T-stat in and new radiator cap. Now have vinegar running in it but there is still a lot of crud in there. I am thinking of flushing with water then doing vinegar again maybe a couple times. Finally running a radiator flush kit, then refill with the green stuff. Comments for this? It's the Vortec V6 4.3L. Thanks all

ifyour still drawing crude out your certainly on ht eright track. Hows the head gaske? I had issues with mine.

I've heard they had troubles with that but I will be the first one to
admit I have no idea, there was no oil in the radiator, and it runs
fine just was over heating from the crude build up. How would I
check that?

You will never get it good and clean don't forget to flush the heater core... I would also had some water pump lube it helps retard rust were rust is a issue...

Check the top end of the rad, where the upper hose comes in. Mine with a 4.3 had a big crack, in the plastic tank, at that point.

Hello,
I may be just coming in on the back side of this post, I read that you have replaced the thermostat, and have flushed the cooling system several times. Have you thought about changing the water pump? if it has high milage the "fins" may have worn to the point that it can't circulate coolant properly. You said no oil in the coolant, but did you check the oil for water? If it is a blown head gasket I have seen them blow at a point where "compression" leaks over to coolant system and can cause overheating. Get you a compression tester at a local auto parts store, run the engine till warm and then one by one take a plug out and turn the engine over and get a reading, then go to the next cylinder and so on. " Note you should take the coil wire off so engine doesn't try to run" Make you a diagram on paper and record your readings for each cylinder. If you have one that's showing a large difference this could give you more information to go on as to which "bank" and cylinder is loosing compression. Also take an air hose an blow out the fins of the radiator you wouldn't think bugs could clog them up but they will.
Hope this helps,

Wayne

My S10 4.3 V6 was overheating last summer. Turned out the left side plastic radiator tank was cracked. Had it replaced and new antifreeze and the problem went away.

Leak was very hard to see. Pressure tester found it.

Overheating and crud in the cooling system? Sounds like a head gasket problem to me.

If it still overheats your radiator may need to be rodded out. I replace the antifreeze every other year. My late FIL thought permanent meant forever until his Ford overheated. I told him his antifreeze had probably lost its rust inhibitor. Had to have the radiator rodded. Hal