Oil pan plug repair/replace

S

sequim

Junior Member
My oil pan drain plug rotates with the soldered in ring, so can't remove the drain plug. I've miti-vac'd the oil out and have dropped the pan. The replacement drain plugs offered by several suppliers seem visually different than the one in the vehicle. Original seems to have lip inside the pan holding it from dropping out. Replacements seem to have the larger flat edge on the outside of the pan, meaning fed up from the bottom.
I'm planning to heat up the old solder and remove the old ring. Should the new steel ring be welded to the outside of the pan (some suppliers say welded), or soldered both outside and inside of the oil pan?
Thanks.....
 
Weld. Test the weld for pin holes and weld them up. Clean thoroughly before welding. Can you weld in the old ring?

Brazing would be the second option. Silver solder is also a good second choice. Soft solder is not the best choice and I would avoid using it.
 
The inserts being sold have a high neck on them that is supposed to be peened over the edge of the hole in the pan (or swaged in place causing a lip to be formed to hold the piece into the pan). After this is done, this internal lip would be soldered, as it was from the factory, to seal from leaking oil and keep the insert from turning when the drain plug is tightened too much. If you have no interest in the insert looking "factory like" from the outside of the pan, tack weld the insert in 3-4 places around its circumference and finish the rest with braze or solder as suggested above.
 
Most people would call it overkill but it is required on race engines to have the pan plug safety wired.
As long as you will be welding or brazing on the plug area consider adding a small tab with a hole in it to the pan alongside the plug.
Then drill across one of the hex corners of the plug. Easy to put wire across then.

Over the years I have seen at least a dozen blown engines that were caused by the pan plug coming out while driving.
 
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I think whatever repair method that I use, that tacking, TIG, or full brazing on the inside of the pan is needed to keep the insert from coming out and to give more area to lock it to the pan - as long as the method doesn't interfere or tilt the oil pump spring. I've got the pan super clean and finished it with Dawn Power wash followed by wipe with grease & oil solvent. Once the old plug comes out, will reclean the hole before getting someone to repair. I'm unable to do that myself.
Does anyone have a picture of their minimal brazing on the inside of the oil pan? I'd show to a welder. Thanks
 
I'd be afraid to weld it, for fear of burning a hole in it. Take it to a heating and cooling shop (good and clean inside and out) and ask them to silver solder it (with a thing called a turbo torch) for you.

Just giving another option...
 
Last observation ........... your original post suggests you'll melt out the old solder and remove the original plug. I don't think so. I believe you'll find that, even with every bit of visible solder removed, there IS that lip you referenced holding the plug in place. You'd need to grind that lip off to safely remove the plug .............. which could cause more damage. Just be careful. Good luck with your endeavor. let us know the end result.
 
Hmmm, was thinking same thing.....can't easily come out. And the insert threads aren't damaged, just can't get the drain plug out. Wondering now as nkaminar noted it might be better to get the original insert silver soldered in place which should then allow me to loosen the drain plug. Or at least worth the first try. Thanks for this astute observation.
 
Some spray carburetor cleaner or brake cleaner might be the best to clean the area before silver soldering.
 
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