Loose oil pan bolts

[morrison]

Hi everyone--just discovered this forum and signed up. I'm a regular on IH8MUD and Yotatech, and now I'm here. Can't get enough Toyota.

Have a question: Anyone know what would cause oil pan bolts to loosen 5000 miles after a thorough, professional rebuild by a highly thought-of engine shop? Engine is 3VZE in 94 4-runner with auto. I was searching for a large oil leak when I discovered the two studs at the rear stripped and all the bolts barely finger tight. As far as I know the vehicle has not been mistreated or overheated. Any ideas?

Thanks!

Jim

[fustercluck]

Are you certain they were tight originally?

[morrison]

No, I just assumed that a good mechanic would torque them down. It looks like they used a cork gasket on the pan and also between the oil baffle and the block. Is this bad? I thought I read somewhere that you weren't supposed to use a cork gasket . . .
Thanks!
Jim

[morrison]

That's what it is then. But I wonder why the studs where stripped--probably not as professional a mechanic as I thought I was paying for. I'm gonna fix it myself this time. Anyone know if it's possible to get the pan off without lifting the engine up?

Thanks!
Jim