I've had the death rattle since 1000 miles. At 6000, I changed to Mobil 1, but nothing changed. Everytime I've brought the car in for sundry warranty work, I always ask the service writer if Ford has any bullitins on the problem. Last week, I brought the car in to have the left front brake caliper replaced because a big chip of red paint marred the look, and also because the serpentine belt had began to leave ugly black marks on the engine block (driver's side.) Anyway, I again asked about the death rattle, so he wrote it up. The next day, he called to say that the mechanic did hear the rattle and asked what oil I was using. He asked if he could replace the oil with traditional, and I said OK. What's interesting, is that the cold death rattle is noticably reduced, but not entirely gone. Progress? Since I purchased an extended warranty and I only have 11,500 on the clock so far, I'm going to continue driving the car hard and see what shakes out. I refuse to let them do any exploratory surgery or give me a re-furbed mill. It p*sses me off that Ford can't build an engine without these kinds of problems. Other than that, TB2127 is the best car I've ever owned!