Removing Plug to Install a Block Heater - Need some ideas

Scotty Dive · Oct 9, 2015

Every year when it starts to get cold around here I start thinking about installing a block heater. The problem I have is the plug doesn't want to budge. What really makes it difficult is I dont have any tool that fits this square plug. Its obviously metric and I am sure its rusted into place from the inside since I am sure its first 25 years of life had rice patty water in it. I have tried to use a socket extension (square) and an impact wrench without any luck and all I have done is I have started to round the corners which makes getting a grip on it even worse.

My latest thought was welding a nut to the square plug thinking the heat might help break the rust down on the threads and then I would have a nut that I can attach a proper impact socket and work it from there. Its very hard to start when its bitterly cold and the tractor sits outside under a deck roof so there is no real way to get it warm. I have to admit I am hesitant to do anything that might do damage to the block so I would appreciate any help. Here is a picture of it before I started to work on it. Since then I have scraped the paint around the threads and hit it with all sorts of penetrating oil over the last few years but it still wont budge. Thoughts and ideas?

gghb · Oct 9, 2015

you might leave the plug alone and use a dipstick heater Iv'e bought them at nappa

greg

flyerdan · Oct 9, 2015

Probably the easiest to install would be a lower radiator hose heater. You could also probably use a frost plug heater, but there is often clearance issues on certain engines.

5030 · Oct 9, 2015

...or pop the freeze plug next to it and install your heater there......(where most heaters normally go....)

aeblank · Oct 12, 2015

I'd be a proponent of a lower hose heater.
Simple and effective.

PILOON · Oct 12, 2015

I would think a couple of decent whacks with a hammer would release the threads enough to screw out that plug.
After all what you want is to break lose any rust that binds the threads, after that it should be typical pipe thread tension or binding.
Some heat also is effective in freeing rusted threads.

CurlyDave · Oct 12, 2015

This is thinking way outside the box, but here goes...

Way back when I was young I had a Dodge van that was very hard to start in cold weather. I had little experience, and even less money. I found that if I lit 3 or 4 charcoal briquettes in a stainless steel pan (try a thrift store) pushed it under the engine and waited 20 minutes it would start easily.

This is obviously not recommended by the manufacturer, but it takes about the same amount of time as a block heater, unless you leave it on overnight, and is very inexpensive to try. I am talking about a small number of briquettes, not a roaring blaze.

Oldtink · Oct 12, 2015

You might check your auto parts store for an 8 point socket. Impact socket if they have it. I had to use a 3 foot cheater on my 3/4" breaker bar to get mine loose.

truckdiagnostics · Oct 12, 2015

5030 said:
...or pop the freeze plug next to it and install your heater there......(where most heaters normally go....)

times 2

Todd8665 · Oct 12, 2015

I feel your pain... Don't really advice good or bad, but here are my thoughts. If the threaded plug refused to come out you could be left with a broken, leaking, eyesore. If you could find a replacement freeze plug before you tried anything, you would have a fallback plan if things didn't work out. I assume that that is a 30mm hole?