Strange material found in gas tank

56napco · March 19, 2013

So this weekend I changed the fuel pump on my '02 Yukon XL 2500 6.0L (180,xxx miles). The pump I replaced (GM Part) I had installed at the local Chevy dealer last March when the pump before that failed (non-GM part) and left me on the side of the road. This pump worked fine other than it was starting to get louder and louder and louder. The new pump (GM Part) is of course silent and is working perfect once again.
The strange part was when the old pump was taken out we found what appears to be chunks of molded silicone rubber in the bottom of the tank.

Could this be from the old fuel pump, insulation or padding from around the pump that caused it to become louder? The pump itself seemed to be loose in the plastic housing leading me to think it was vibrating. I've never seen anything like this before in a fuel tank. I've never run any additives in my fuel, other than Heet a couple times, and typically run 89 octane w/ 10% ethanol (cheaper than 87 octane here). Any thoughts?

8.1HD/ALLISON · March 20, 2013

Possibly could be insulation or pad around old pump? Hard to tell. Looks like deteriorated plastic or fuel line to me?

Ianf · March 20, 2013

Has someone been trying to siphon gas out of your tank and lost part of their hose?

56napco · March 20, 2013

I have no idea if anyone has tried to siphon fuel. My Yukon has the dual tanks so anything that would go into the rear would then have to travel to the front (main) tank where this material was found. I drive my truck everyday and never noticed the fuel level to be lower. Never dropped the rear tank so who knows what could be in that one after 180,000 miles.

56napco · September 17, 2013

Here is a working picture of what was found in the tank. Truck is back in the shop again 6 months after a new fuel pump was installed with possible fuel pump issues again. Still waiting to hear the diagnosis.