[48aero]

I had my 4.3 v6 bored, vatted, freeze plugs,and cam bearings done at a local machine shop. After I assembled the engine and went to build oil pressure to adjust the valves I saw oil on the floor at the back of the engine. I ended up pulling the trans and found one of the oil gallery plugs had been run in too deep and split the boss it screws into, and oil was poring out under pressure. I contacted the machine shop and they said it couldn't have happened when they put in the plug. I forgot to mention that the leaking plug is in the block about 1/8 of an inch and the good is proud of the block by 1/8 inch.

What I want to know is, can a tapered pipe plug be driven in deep enough to crack the boss? Has anyone ever heard of this? Please help I meet with them Fri, I'm pulling the engine to show them. Thanks Jesse

 

[ericnova72]

Yes it can be driven in far enough to crack the boss, that is exactly what happens when they are driven in too far. It would take a good size breaker bar, or more likely an air rachet or air impact gun (Auto techs have these permanently attached to their hand and hate turning threaded fasteners by hand). Somebody screwed up. Probably wouldn't seal, so instead of removing it and using thread sealer they kept tightening hoping to force it to seal.

 

[001mustang]

getting nothing

I came to you post because I was jealous. :drool:

Now I feel sorry for you.

Nice of them to disown the problem; no investigation required.

Do you have any evidence it was ok before rebuild(stupid question)?

 

[richard stewart 3rd]

Hi,
Pipe thread is tapered, causing boss breakage if tightened to much.