TORONTO, Ont. – With the first wave of equipment now tested, shops are finding that truck engines built throughout the ’90s are easily passing annual Drive Clean inspections. And those we contacted are failing onlyfive or seven out of every 100 that roll through the doors.

“We found that some of the older mechanical engines, obviously, are more apt to fail,” says Scott Colby of SN Diesel Service in Concord, Ont.

When newer engines fail, a minor repair usually makes the difference.

“At some point in time, the fuel pumps have been turned up to give more power,” Colby says of the most common reason for failures that his shop has found. “Most of the fixes are backing up the pump toward spec’s. It’s a fairly quick, simple procedure.”

“Quite frankly, most of them (that fail) are old units guys haven’t kept up ,” agrees Don Sisti of Toromont Cat.

A common issue with older Caterpillar engines has involved adjustments to Air-Fuel Ratio Controls, and $270 later the trucks are back on the road with a certificate of approval in hand, he says.

Some electronic engines have needed governors reset, says Bob Costens of Toronto-based Computrux, who has seen engines of every age and model fail. And those that do fail tend to fail by a wide margin, he adds. “It’s just total neglect in those cases … the trucks that are getting regular visits to the maintenance facilities are rarely failing.” n