In preparing for this weekend's racing at Atlanta Motor Speedway, Toyota Racing Development will go with the type of oil pumps used on its Sprint Cup engines last season, SceneDaily.com reported Wednesday.
At least four of the Toyota teams changed their TRD engines at Las Vegas Motor Speedway last weekend and two teams made changes the week before at California's Auto Club Speedway.
Modifications used after qualifying at Las Vegas will also be kept in place at Atlanta, the site reported in an article by Bob Pockrass, an associate editor.
In a news conference Saturday at the Nevada track, TRD's president Lee White narrowed the problem to lifter or camshaft issues and said engines were damaged within the first 75 miles of use.
Michael Waltrip Racing, Red Bull Racing and Robby Gordon Motorsports use TRD engines.