Have a 2000 Deville with 4.6 N* with two oil pan bolt holes with damaged or pulled threads. Will heli-coils hold as a permanent repair.

Sure.

Yes, that is a low stress fastener. You might consider tapping for the next larger bolt and opening the hole on the pan slightly to accomodate.

use some lock tight that should work too

Thanks to all for the quick replies. Heli-coil it is.

If the engine is still in the car, and it isn't leaking, I would just silicone the holes up. If there is a leak though, fixing it proper would be better.

Don

Another thought is the thread forming epoxy. I've used it and it works for low stress threads.

This is a kit, I think loctite puts it out.

The epoxy thread repair kit is kind of iffy unless you can thoroughly clean the hole and keep it clean during the repair process. Sometimes hard to do, laying on your back with oil dripping in your eye.

dkoz, true, just thought I'd mention it though.

Are you SURE the hole is stripped? The reason I ask is that the actual hole is a hardened steel piece that is pretty hard to strip with a standard soft steel drain plug. Usually the plug strips and leaves the threads in the hole "looking" stripped but it's just the metal from the bolt stuck in the threads of the hole. Make sure before trying to re-tap the hole. If you really have a stripped hole, the rubber replacement plugs seem to work the best.

Drain plug? Kevin I think he's talking bolts as in what holds it on to the block.

wecampbe, what else did you have to remove to get the oil pan off? Looks like the exhaust crossover is in the way, and then it loops over the trans to get to the Y pipe.

Damn! My bad, thought he was talking about a drain plug.

davesdeville: Have not pulled the oil pan down. The cradle will have to be lowered to make the repair. Had a lower crankcase reseal job done in December of 2004 by a local cadillac dealer. One of the bolt holes had a odd ball bolt installed because of stripped threads and the tech reinstalled the bolt instead of repairing the hole while the engine was out. Now I have a slight oil leak at the front of the pan. No way to make the repair without lowering the cradle.

Have you though of chasing the thread with the next larger size tap of the same thread pitch with the pan in place? Since this is not a critical joint or a high torque joint, that may work and save you a lot of time and effort.

There is a sealing compound that looks like strawberry jam, that you can smear over the leak, sets up with a spray on primer, and sticks like poop to a blanket. Loctite 518 and 7648 Activator.

A good first step is to use one of the "leak trace" oil dye products available at auto parts stores to find exactly where the oil is coming from. A UV light helps as the stuff fluoresces. Wind whipping around a car spreads a small amount of oil everywhere. Once the exact source is identified you can devise your strategy for a fix.