The number of West Palm Beach city vehicles with engine failure is now up to almost a hundred.
City officials say it will cost more than $500,000 to replace the engines.
Of the 68 police cars and 47 other city cars that are affected, 61 police and 38 city cars are back on the road.
The problems started in late March when several new police cars suddenly reported engine failure.
At first, West Palm city officials thought it might be an issue related to the car make and model.
Ford was called and they took some of the engines to Detroit to investigate.
But then Miami-Dade also reported similar issues.
"It's interesting that it happened to both of us at approximately the same time," said Jose Galan, Assistant Director of Internal Services at Miami-Dade.
Miami-Dade reported 217 were impacted, 67 of which needed their engines replaced.
Miami engineers started to talk with West Palm engineers and they both noticed the same symptoms: oil in the air filter.
Galan said he's never seen anything like this case before.
"I've talked to our fleet guys and they've been around for some time and it's the first time they have heard of anything like this," Galan said.
Turns out a bad batch of fuel shipment was to blame.
What was supposed to be unleaded was tainted with diesel, slowly killing city engines.
Ford concluded their investigation and said that excessive gum and soot on the engines as a result of unburned diesel caused the engines to function improperly.
"The fuel broker did replace approximately 20,000 gallons of fuel," Galan said.
Miami-Dade and West Palm use different fuel brokers. Where the fuel brokers got the bad fuel shipment from is still unclear, along with the question who else might have gotten it.
The investigation continues and West Palm Beach and Miami-Dade are hoping the fuel brokers' insurance companies will cover the cost.
Scripps Only Content 2018