Exhaust Manifold Water Plug

I bumped into a few of those situations myself. You can do a couple of things. Try cleaning up the threads with a wire brush. If that doesn't get you where you need to go then take a sharp pick (like a small ice pick) and work it around the threads scraping out the buildup, then clean with a wire brush, and spray with oil. If the plug looks damaged you can always replace it. Heating it up with a torch will also break the buildup loose, but you need to get it to turn color for it work. The expansion breaks the crud loose. All of this is for the plug, not the block or manifold. You can buy small round wire brushes from tool stores along with small picks bent at 90 degrees that will work for the block or manifold, use no heat.

You should be using brass not galvanized plugs will corrode(sp), rust and fall apart lead to your problem.

My Plugs are brass. It is where they screw into is full up crap. So I have to clean the threads out.

I would need a 3/4 in pipe tap. Where do I get one, if nothing else works?

    I cant remember off the top of my head, but do you have to take the riser off to get the tap to fit???

                                Jeff....

Jeff:

Excellent observation and yes, I think you are correct.

The riser is the elbow on top of the exhaust manifold or the part that the exhaust hose clamps to. So, you will need to purchase a new gasket before you remove yours (if you go the tap route). Just note the orientation of the gasket as it can be installed two ways, and one way is wrong.

Try cleaning the threads as noted above. 15 minutes spent cleaning it up might save you the hassle of taking it apart and buying a tap. If it doesn't work-go shopping!

Ideally, cutting oil. But, any oil will do just fine because you will be going slow. In fact for simple thread cleaning, I do not even bother with oil at all...depends on how bad the threads really are.

    Personally, I would not use oil, and run the tap in easy until it feels resistance, remove the tap, and flush the hole with water to remove the debris. Do this several times as going "one shot" might cause the debris to roll or gall the threads.

                                Jeff...

Anything I can spray in the hole to loosen the crap up.