Taping an Engine bolt hole

[SwiftRunner]

Before I bought my 4-runner, the engine was rebuilt. The guy screwed up a valve cover bolt hole, crossing the threads. I have an oil leak and am thinking about drilling out the hole and taping it. I've never done this kind of work, but do have the tools. Is it a tricky job?

 

[chevtruknut]

hole tap

The better way to do this is what is known as a "Heli Coil" (that is a brand name, several kits of the same around) What you will have to do is tap the hole out slightly larger, then you will have an "insert" that goes in there, that restores the ORIGINAL thread size. they are actually stronger than stock in many cases. Just take in your original bolt to any auto parts store (good one) and the kit will run 20-30. It is more than just tapping the hole, but a better fix, and no need to ream out the valve cover and risk damage to the gasket set. Just my opinion and what I would do. Good Luck. Brad

P.S. VERY IMPORTANT!!! Whatever you do use a ton of rags or whatever to ensure NO metal shavings get where they don't belong. Just one can ruin your day (and motor) Simple precaution will avoid this from happening.

 

[SwiftRunner]

Thanks for the reply post. I'm familiar with heli-coils. I used them when working as a ski mechanic. However, we hammered them into the ski when the binding mounting had been stripped. The original bolt is gone, but I can use a similar one. When the mechanic had stripped the metric bolt, he inserted an SAE which was big enough to make it past the initial use of the engine.