Actually you could have 1k and have the motor rattling. They dont put A+ parts in all the cars they make. Thats why they color code everything. Green means no problems. Yellow means Slight problems and red means 50/50 could break anyday. Working at my cousins shop a guy who worked at saturn for 10 years came up to me and told me that. I dont know what blue means but my 01 mercury has blue and green in it.