I think GM must be sourcing timing chains from a substandard manufacturer. A guy I work with just had a problem with his Traverse timing chain. The dealer told him that it had stretched prematurely due to the oil change intervals being too long, even though the OLM said there was somewhere around 30% oil life remaining. The dealer replaced his under warranty but now his engine has a hum/whine that wasn't there before and the dealer says it is "normal for the engine".

100,000 miles should be nothing for a timing chain unless the engine was beat to s@#t, Hondas use belts and their maintenance schedule calls for replacement of a belt at 100,000 miles. If a chain is going to last no longer I say they switch to belts and make it easier to replace.

 

The 3.6L in the Traverse/acadia/outlook and other GM cars does have timing chain issues(just search on one of their boards), but the 4cylinder ecotecs do not appear to have problems as frequently. Considering the amount of people on this board, there haven't been very many timing chain failures.

 

You still have all the same parts to remove to get to a belt as you do a chain. You just have to make sure you put the front cover(s) back on on cars with chains .

Another thing to consider is that chains do not tend to break. They can jump but so can a belt. They do stretch but they are not know to over stetch at this milage point. But when they do stretch they will mess up timing and give you some heads up of an issue. A belt that snaps gives no warning and if the motor is an INTERFERENCE motor then you will trash the head if not hurt the pistons. Timing chain engines are more times then not interference motors but as long as the chain stays intact your head should be fine. Again chains breaking is very very rare so this last issue is of very little concern.