2005 SV211 PCM 330 block drain plugs

[blawson327]

What am I doing wrong here? I took the old plugs out to winterize, they don't look good at all, so from what I could tell the block, elbow and v drive are all 1/4 npt. I can't get the new ones to thread in more than 1/4 turn by hand.

Did the originals get cross threaded at some point and muck up my threads in the block?

[SilentSeven]

Not uncommon...especially for the manifold drains.

The block parts are cast iron; the plugs are brass by design. The plugs will deform before hurting the block. When you have older manifolds, what you see is typical. As long as they don't leak you are fine.

Here's what you don't want to do - don't remove the plug and leave it out over the winter. If you leave the plug out, the threads are air exposed and water will drip over the cast iron threads causing the block side plug holes/threads to rust out. This is nearly unrecoverable. What you want to do is pull the plug, drain, and then promptly re-install the plug. Teflon thread tape is useful.

If you don't want to deal with pulling plugs, do what I did and swap to petcock type engine drains. My exhaust manifolds and engine drains have been converted.

Skidim used to sell a block drain kit for a reasonable amount of $; now they sell just parts for $$$$. You can build your own with a little bit of planning and a good plumbing supply store (or grainger). https://skidim.com/maintenance/engine-drains.html

[blawson327]

Thanks for the sanity check.
I was at the point to even question if the old plugs were replaced by the PO at some point with the wrong ones.
This has been on my list to replace for a couple years, but usually don't think of it in time before winterizing.

Luckily I've never left them out for very long, as I fill with antifreeze for winterization, but who knows what the PO or dealer has done over the years before I got it.