The Chrysler Jeeps in question in this case, for model years 2012 to 2017, have a cylinder head on top of the engine that is made with sand casting. The complaint alleges that the sand is not sufficiently removed but seeps out as the car is driven, working its way through the car’s systems and settling in the heater core, radiator, and oil cooling systems as a thick, reddish, sludge that builds up until the heating and cooling systems stop working properly. Chrysler has refused to pay for repairs required by the problem, the complaint says, claiming that the problem is caused by “external factors” or “misuse” or that the vehicles are out of warranty. However, the complaint points out that buyers cannot know of the defect until the systems actually fail. Among its other claims, it requests a declaration by the court that the repairs should be covered under the Powertrain Warranty and an extension of the Basic Limited Warranty.