Coolant Drain Plug Jammed

[horspowr1001]

Hey all,

I have a 98 Camry with the 1MZ-FE V6 engine, 156K miles. Today I decided I'd change the timing belt and water pump. I also figured I'd drain and flush the cooling system while I was at it.

I drained the coolant from the radiator as well as the block drain plug closest to the front of the car, which all went fine and dandy. The problem came in when I was working on the drain plug on the opposite side of the block near the firewall.

So I loosened it maybe 3 or 4 turns and it stopped turning, so I figured it was one of those valves with a stop when it's fully open, like a valve for your garden hose connection. Okay, that's fine, I said. After the coolant had drained from the drain tube that's adjacent to the drain plug bolt, I tried screwing the bolt back in, which is where everything went to hell.

The bolt turned maybe 1/8th of a turn and stopped. Now normally, this would indicate cross-threading. However, I didn't completely remove this bolt, so I found it really odd that it wouldn't find its threads again.

So I turned it a bit harder, thinking that it had gotten caught on some dirt that may have settled on the threads inside the valve. No dice. So I loosened it again and started wiggling it as I turned it in, hoping it would find the correct threads. Still only the 1/8th of a turn. Tried the same thing a few times more to no avail. I could also feel the bolt starting to round a bit.

So I tried just barely heating up the area around it with an oxy-act torch, and then turning it in carefully. Nothing. I tried more backing out and turning it in, and still no dice.

So I'm stuck with an open coolant drain plug, which you can see from the pictures below, is now pretty damn rounded. I've only come up with a few solutions so far:

1) Attach a small rubber hose to the end of the drain tube and plug it with a brass fitting on the other end and hope the hose clamps keep it there.

2) Drill and fit another bolt inside the current one or cut a new hexagonal bolt head pattern, then heat it up even more, and then try tightening it.

3) Replace the part.

Now the issue with #3 is that the valve is actually part of what appears to be a larger single-casted piece that seems to have multiple functions. I say this because above the drain plug, there's a connection for a ribbed metal line that feeds into the exhaust manifold (See pictures).

I originally thought this was part of the PCV or EGR system, but I couldn't find anything in my Haynes manual that showed this connection to the block. So I even if I wanted to replace it, I have no idea what this mystery part is called.

Does anyone have more ideas or know what this part is?

Overall shot for orientation:
http://img189.imageshack.us/img189/4...9550edited.jpg

Close-up (intermediate axle is in the way):
http://img216.imageshack.us/img216/8...9551edited.jpg