A really Bad Day in the garage
 

I have a 1965 GTO with the original 389 engine that is running fine. I have owned this car for many years and can't recall the number of times that I jacked it up in the garage with no incidents. Went to lower the car down off my jack stands, and for some unknown reason, while lower the front, the floor jack under the front cross member slipped and the oil pan landed on the jack lifting pad. The oil pan is is now deflected up approximately 1/2 inch. The car only has the original idiot lights, a local knowledgeable 'engine' fellow that I know suggested attaching a remote oil pressure gauge and slowly start up the engine to see if there is oil pressure. The permanent fix would be to pull the engine and straighten out the pan, but time does not allow me to start this at present. Looking for opinions as to if the engine still has oil pressure, would it be wise to drive the car as is? Also what pressure would be typical for a high mileage 389 with OE oil pump. I might add the car is in a warm climate therefore cold high viscosity oil would not be an issue.

Take the spark plugs out and attempt to turn the crank, via the dampener bolt, see if you can hear any scraping, or if the crank won't spin a complete round....then...
Can you post a picture????

I pulled a dent out of and oil pan with 2 small suction cups for body work. They are real strong. Harbor freight even sells the little body suction cups. I also have a large suction cup. The small is about 2-3 inched in diameter, the large 3-4. Might be worth a try, better than pulling the pan.

Simple to pull out if you have access to auto body stud welder dent puller , have done it with great results . As long as it did not hit the oil pump pickup unless the pickup is welded , could cause it to fall off & that would not be good .

been there done that twice in the front of the pan damm detroit locker it won't roll forward while jacking pulled the motor both times

The suction cups should be able to do it.

Half an inch likely isn't enough to move the pump pickup.

You're luck it only caved in by that much, once you get most of it pulled back into shape you should be fine.

There is reasons why you should not weld to an engine part while the engine is together, I do not know if I believe it, but I heard it is possible to damage bearings and rings grounding the engine while welding. Just something someone told me. Seems possible, so I would remove before I weld.
Plus the stud welder will leave a mark you have to grind and paint.
try the suction cup first.

I would think this would be true if you grounded the welder to a head, and then welded on the pan. But as long as you keep your ground close as possible to the work area I surmise that the current would take the shortest path.

Maybe, but if there is any small metallic chips in the oil it could arc and mark a bearing... many theories I play it safe, but would not debate it either way. Unless I had first hand bad experience would I say for sure.

The stud welder electrical current only flows from the stud to the project piece then to the stud welder outer ring. The outer ring is about 1 inch diameter. So its very localized electrical current. The only fear I see is, sometimes (rarely) when you are pulling on the studs they will pull a small chunk of the project metal off creating a hole. This hole would then need to be welded shut or brazed shut.
Good luck.

if you choose the stud welder practise on some scrap first to get a feel for how long to pull the trigger. otherwise you might burn a hole in the pan.

A really Bad Day in the garage
 

I appreciate you all taking the time to reply. I will try suction cups first and update the results. Thanks.

[QUOTE=JSPONT;5337973]There is reasons why you should not weld to an engine part while the engine is together, I do not know if I believe it, but I heard it is possible to damage bearings and rings grounding the engine while welding. Just something someone told me. Seems possible, so I would remove before I weld.
Plus the stud welder will leave a mark you have to grind and paint.
try the suction cup first.[/Q Dang a body shop stud welder only spot welds where it touches it doesnt send current thru out the whole engine, or from wherever a ground lead is attached over to where ever the welding rod is touching, dang learn something!:usa2:

by a cheap one at harbour freight and do it yourself:usa2:

Oil pickups are generally set at 1/4"-3/8" off the pan. It's likely that the pan is up against the pickup, and even if it has oil pressure, the volume may not be there. I would pull the dent and not start it. Also, it may have loosened the pickup as mentioned earlier.

Good luck! Hopefully it turns out OK.