Where is the engine block petcock/drain plug on a 98 Chevrolet S10?

Question

I'm trying to drain all the water out of the system I put in my truck because it was leaking coolant due to an intake gasket being blown. I didn't know the gasket was blown at the time and putting more anti-freeze was getting expensive, so I went to just adding water. I've drained the radiator petcock but I know there's still water in the block. So I was wondering if anyone could tell me where the petcock is located or perhaps another way to drain the water from the block?

I forgot to mention the reason I kept adding anti-freeze was because I was replacing/checking hoses and other parts hoping they were the problem (because I REALLY didn't wanna take my engine apart). And as I was replacing them, I lost coolant little by little in the process. So to save money from the $12 a gallon anti-freeze bottles (they add up quick), I switched to water until I was sure I'd fixed the problem.

I'm pretty confident someone has given me the right answer. But they brought up a good point, and I figured I'd post the details of my engine and give the question another day. The person whose answer I'm talking about wasn't positive where the drain plug was on the right/passenger side. He wasn't sure if it was the knock sensor or a drain plug. I'm posting the details of my engine so he can possibly tell me which one or someone else can tell me which one it is.

I have the 4.3L V6 Vortec engine with EDI and CSEFI it's a 4 speed Automatic transmission


The water I used was my well and it's hard water that is full of many minerals. I'm worried about the damage the water will do to the iron block. If it was distilled water, I could careless about leaving it in there.

Answer 1

If you are looking at an intake gasket leak, you are probably talking about a 4.3L V6. There are two block drains on that, one on each side. They are just above the oil pan, accessible from the bottom. They are just behind the motor mounts. On the left side, it is a 9/16 pipe plug. On the right, it is just forward of the starter. Depending on which version of the engine, it may be a 9/16 plug, or it may be the knock sensor. Sqeeze the single wire connector on it to release the connector, and remove the sensor. When installing the sensor, keep in mind that the torque for it is 15ft/lbs. Not much. Overtightening it can cause it to fail. If you pull the plugs and nothing comes out, us a small screwdriver or a stiff wire to poke thru the debris in the bottom of the water jackets.

Answer 2

Some older engines had threaded drain pipe plugs on the lower sides of the block above the oil pan but not sure if yours has this or not--you can check. No real need to drain the block---- just flush the system and drain the radiator, then fill with proper amount of coolant, run the engine for 20 minutes or so and get a coolant tester at a parts store and test the system to see if the coolant protection is where it needs to be --add more coolant or water if necessary.

Answer 3

I'm no mechanic, just a shade tree type, but I've never heard of a petcock on an engine block. My suggestion is to remove the bottom radiator hose and drain it that way.

Answer 4

The water level in the engine is going to be below the level of the heads by about three inches if the radiator is drained.

There is no drain valve on the engine.

Answer 5

It isn't on the engine block, it is on the lowest point on your radiator, look at the back of it at the bottom, probably drivers side. P.S. If you run an engine very long with just water in it the water pump will fail due to lack of lubrication!

Answer 6

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