350 engine and gas tank question

i found a hole where the screw goes in on the passanger side near the rear of the engine. its a regular screw hole but dosent have a stop point, i haven checked it yet to see if it sucks in air. dont no if its sapposed to be like that or not…



and does any one now y a gas tank would suck in air after i remove the gas cap, after a couple of starting tries, i did remove the tank and patch up some pin holes on it

Before I spill my guts about everything I know that could cause negative pressure to build up in a gas tank you are going to have to tell me a good number of details about the situation, does the “sucking air” seem to affect the engines performance? is the tank being “sucked in”?

yes it did suck the tank in, thats what made me check the cap to see if thats what it was, it also made the buckling. and as far as performance, i dont no at the momment i just reinstalled the tank, and and when i tried to start it no gas went into the clear filter and after a couple more tries the i heard the bucklin sound. so i didnt even get to start the car. wanted to see y it was doing this first

Well what is this mystery vehicle? typicaly it takes hours of running (and fuel leaving the tank) to start sucking the tank in, you sure about these symptons?

Year? Model? Mileage?

81 chevy malibu its freshly rebuilt only a couple of test runs. and these pics are of the scre hole location, it felt like it was pushing air out not alot though i pluged it with a screw. the green engine is mines the blue engine is for an example, of the hole location

I could be wrong but I think that’s the hole you’d use to screw in the clutch arm pivot if you had a standard shift.

If it’s an automatic the hole would be empty.

Other than that if there’s no oil leaking out you would be good.

And is that car a right hand drive? The pictures show the hole on the left side of the engine which would be driver side in the US.

its a left hand drive, would it be coo just to plug it up with a screw.

That’s what I would do.

I just have to say it, This reminds me of probably 30 or so mechanics that pulled up to the shop with a freshly rebuilt engine and asked if I could set the timing for them. How does basic system operation get passed by a man who can do what the pictures show, I will never understand this one.

OK, I have it, we are being scammed, and I bit on it, HA,HA.