PORT ALLEN — Fuel pumps at a West Baton Rouge convenience store are shut down after gasoline was put in a diesel storage tank and diesel fuel was put in one holding gasoline, then sold to unsuspecting customers for nearly two days.

Motorists who filled up recently at a Circle K near the Lobdell exit off Interstate 10 in Port Allen shouldn't run their engines until their vehicles can be checked out. A mechanic may have to drain the fuel system.

Affected drivers can file a complaint online with the state Department of Agriculture and Forestry, or make a complaint by telephone at 800-247-1086. The state agency governs gas stations.

The department's commissioner, Mike Strain, said the fuel tanks had been filled Sunday but the error was not discovered until a complaint came in Tuesday morning.

"We contacted the station. The station voluntarily shut down its pumps immediately," Strain said. A check for water in the tanks turned up negative, then tests at a LDAF lab showed the fuels were in the wrong tanks.

"What we believe happened is that there was a cross-drop," he said. "What that means is that the delivery driver inadvertently put gasoline in the diesel tank and diesel in the gasoline tank."

If the cross-contamination is confirmed through further testing, the tanks will be pumped out and their contents either reprocessed or disposed of, Strain said. "Then the tanks will be refilled and then we will retest the tank and if everything is clear at that point they will be allowed to sell fuel again."

Strain said motorists can also file a complaint with Circle K in addition to notifying his agency.

Yellow bags labeled "Sorry, Out of Service" covered pump handles at the Circle K along La. 415 Tuesday afternoon.

While a vehicle that runs on unleaded gasoline can't and won't operate with diesel in the tank, filling up with the latter won't necessarily cause long-term damage. A tow may be in order, but once the car or truck is at the shop, mechanics can drain and flush it.

Diesel fuel is thicker than gasoline, so if you did run the engine, it may have clogged the fuel filter.

In a worse scenario, that diesel may reach the injectors and clog them, as well. That could result in the engine seizing up.

If for any reason you think diesel got into your tank, do not start the car, and call an automotive expert as soon as possible.

You'll want to get that drained and replaced immediately.

A manager at the Circle K location declined to discuss what happened and WBRZ has reached out to the corporate office for more information.