Ford Motor Co. has filed a lawsuit against Navistar International Corp. over warranty costs and the prices of the diesel engines it supplies the auto maker, Bloomberg reports.

In the filing, Ford alleges Warrenville, IL-based Navistar owes it money under an agreement to share engine warranty costs, which it says Navistar has failed to pay.

Navistar diesels, which Ford uses in its best-selling line of Super Duty F-Series pickup trucks, have been the subject of various quality issues in the past.

Also in the lawsuit, Ford says Navistar began raising prices for the engines “without adequate explanation or support for its actions.”

Ford seeks reimbursement equal to what it says it overpaid for the engines.

A Navistar spokesman tells Bloomberg the lawsuit is “totally without merit, and we’ll vigorously respond in court.”