I think it was at about 80,000 miles that I replaced the chain tensioner with the redesigned version from BMW. They increased the amount of travel to keep the chain tighter longer. I don't know when that went into X5 production. I think it was in sometime in 2003.

About a year ago I purchased a timing chain kit when they went on sale. Just waiting for unusual or extended noise on startup. I now have 119,000 miles on an engine that was modded at 2,500 miles after purchase and much more along the way.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas