99 Z28 - 176K miles, I shouldnt be surprised its held up quite well for a car with this many miles, but its also still my DD and its going through 5 quarts in 1k miles. I only found out today when I found a small puddle of oil on the ground on my driveway and decided to check the crankcase to find its completely empty.

I didnt want to do this but I refilled it with 1 quart of bars stopleak and 4 quarters of 10W40 ( I have plans on replacing this motor, I just need it to hold up until I can. )

My first question is how much damage can I expect from the stopleak?

My second question is, do you believe its coming from the rear main seal? I havent had a chance to really go under there and look yet but I am only speculating.

 

I reread your post so I deleted mine. Why do you come on here and ask where your car is leaking oil from when you haven't even bothered to look yourself? How in the heck are we suppose to know if it's the rear main seal or not?

It could be the rear seal, the rear engine cover gasket, timing chain cover, oil pan, harmonic balancer seal, valve covers or the OPSU.

 

Spray the bottom end off with brake clean and start fresh. Remove all the oil
from the bottom end/top end of the engine. Fill it to the proper amount of oil and
check underneath the car while it is running for any source of leakage. First step - visually try to see where the oil is leaking. Let us know what you find. Don't use stop leak, clogs oil
galleys, they don't tell you that on the bottle.

 

Yea I was afraid of that. Should I do an oil change and drain it all out right now and start with fresh oil because I already added it? Would it still be safe to use 10w40 till I can fix it?

 

What viscosity you use really doesn't matter. A leak is a leak.

Can stop leak clog the galleys? Yeah, maybe. It's already in there, so I wouldn't worry about it too much. I would say leave it in for now. If it slows your leak, good. You already know it's a band-aid fix, and might get you far enough that you can rebuild the motor.