So this cold has made working outdoors brutal and I think it contributed to finding white plastic chips on the dipstick this morning. For anyone who has had the guides fail is this a good indication of falling pieces. There have been some noises that could be mistaken for very cold idler pulley bearings but also this morning, amongst other noises was an intermittent light scratching noise from the front of the engine but then really only the muted sound of injectors? Odometer is at 262000, kms or 163,000 miles so i guess i am coming into the mileage range when failure occurs. About 20 starts ago there was a short rattle on start-up which has repeated a few times since but very rarely heard before this.