What is this bolt?

**mhunt** · 12-19-2016

I have a 2000 Grand Prix 3.8L and I noticed my car has oil running down the passenger side of the engine and it appears to be trickling out of a threaded hole on the side of my engine. The hole is just below the lower intake gasket but above the water pump. I found the below picture online of the side of a 3.8L engine and there appears to be a bolt (marked with yellow arrow) but my car is missing this bolt and just has an empty hole. My question is what is this bolt? Does it go to anything inside the engine? Do I need a certain length or can I just pick up a short bolt at the hardware store that matches the threading to screw in a stop the oil that's trickling out?

**Scottydoggs** · 12-19-2016

looks like it does nothing you need to worry about.

**Turbocharged400sbc** · 12-19-2016

its a through hole to the inside of the crankcase, oil mist/pcv vapor will exit it if no blocking bolt is installed.

m10x1.5 thread, less than 15mm uhl/thread length. that hole is used on the older g/h body engine mounts that make it a pita to change the belts.

each cylinder head also has a through hole near the injectors that is only used on certain models/mounts/accessories that provide the same leak path from the crankcase to the outside world.