My car is in temporary winter storage. I filled the tank before I put her away, and today noticed some black gunk on the garage floor I thought at first was from leaking diff. But actually it appears to have seeped from the left side of the gas tank. Very sludgy gasoline stuff. Not a whole lot, but it may be coming from the seam on the far left side of the tank??? I cant tell.

I wiped it off the tank.

Or possibly some of it is coming from the little hose on the left rear of the tank. We have this crappy alcohol blended gas here in the winter I had to put in a few weeks back. Anybody ever seen anything like this before? InMmarch Ill drive it to run the gas out and maybe pull the tank.

Sounds to me like the tank could be sweating or have a small leak that is loosening the Undercoating on the tank. The gas is breaking down the tar in the undercoating and turning it to a sludge like material, then slowly making its way down the side of the tank to drip on the floor.

If it smells like gas and looks really dark or like undercoating, Thats probably what it is.

My 2cents,

Dave.

Sounds to me like the tank could be sweating or have a small leak that is loosening the Undercoating on the tank. The gas is breaking down the tar in the undercoating and turning it to a sludge like material, then slowly making its way down the side of the tank to drip on the floor.

If it smells like gas and looks really dark or like undercoating, Thats probably what it is.

My 2cents,

Dave.

I agree. Leak could be (hope so) from the vent hose on that side of the tank. Better the leak be from the hose than a hole in the tank

"Sweating" sounds like a good description. I couldnt really determine the source other than along the side of the tank. Is there a seam on the left side of the tank? What exactly is the Undercoating anyway? Do you think it could be mixing with gas inside the tank? I have a clear gas filter and don't notice any discoloration.

"Sweating" sounds like a good description. I couldnt really determine the source other than along the side of the tank. Is there a seam on the left side of the tank? What exactly is the Undercoating anyway? Do you think it could be mixing with gas inside the tank? I have a clear gas filter and don't notice any discoloration.

Undercoating is the coating under the car. Its the Black, hard, tar based substance that protects all the metal under your Z. its the stuff that flakes off the inner wheel well when your tire explodes. Without the coating, you'd just have paint under the car and more likely, alot of rust.

It can be componently broke down with gasoline. And look like oil after it drips off the gas tank.