trackdaycareracer

I over-torqued the drain plug today after changing to a new plug and gasket. I was sure the workshop manual read 73 ftlb, but later found out I had switched the numbers around - it should have been 37 ftlb... The engine was cold during the change, so I am concerned the threads will fail when the engine gets really hot and then cold again a few times.

Now what, should I take the plug off, change to a new gasket and tighten to the correct torque? Or just leave things as they are?

JimV8

You're lucky the threads didn't strip at 73. I'd loosen and retighten at 37. Probably a good idea to replace the crush washer.

trackdaycareracer

Yes, I was lucky. Still worried about potential damage to the threads in the oil pan though. Do you think it is a good idea to heat the drain plug with a heat gun first?

dougs968

I agree. Definitely replace the crush washer.

dougs968

I can't see how it would hurt, just don't torch your car. The oil remaining in the oil pan threads should be sufficient.

Did you feel that when you tightened it to 73 any yield? You can feel it when bolts stretch or threads strip, usually and especially if you are using a dial type torque wrench, you can't get it any tighter. We test hardware until it fails at work sometimes with this method.

User 41221

Don't use a torch, just run the car to normal operating temp and then put the wrench to it and break it loose, but don't remove it. Assuming it breaks loose okay (which it should), let it cool down and then go ahead and replace the crush washer, put the plug back in and refill.

Julian Allen

You've received good advice about what to do.
I've seen that many pans have a Helicoil in the drain opening threads. Probably helped you to not damage the threads.

trackdaycareracer

Thanks for the help guys, much appreciated.

The drain plug loosened within half a turn, and I tightened it back to 37 ftlb. It seems everything is fine.

Tightening to 73 ftlb, I never came to a point where the drain plug felt like it started to yield. Instinctively, it felt really wrong to use that much force though, wish I had gone back to the house to check the workshop manual again.

A new washer will be ordered tomorrow.