[me and my metro]

Some modern "clean" Diesels inject fuel on the exhaust stroke to heat the cat to burn the soot in the exhaust filter. This regen process works fine if you happen to be driving on the highway. I work for an electric utility and this system has caused a lot of problems when the regen process gets interrupted. Our trucks often run at low speeds and run a power take off to power the boom. The regen process only runs while driving. Unburned fuel ends up in the crankcase diluting the oil. That and all the high pressure fuel system is under the valve covers, if something leaks it stays inside. The oil capacity is 15 quarts and we have to monitor oil level for over level. We have drained as much as 25 quarts of diluted oil from these trucks.