On my next oil change, coming up in about 4000 miles, I plan to place the car in front end service mode and knock off a bunch of oil-related items from the to-do list, as I have some slight seepage from the usual suspect areas. These include the valve cover gasket with spark plug tube seals, oil pan gasket, crankshaft sensor o-ring and camshaft sensor o-ring. Am I overlooking anything else?

While I have everything apart, should I also change the timing chain tensioner? I have 116,000 miles on the car, and the one in the engine functions properly with no rattle, and I usually subscribe to the "If it ain't broke, don't fix it..." idiom, but is the TCT one of those items that eventually WILL fail, and changing it now will be insurance for "when it happens" in the future?

 

IMO I would and did on mine when I was doing my clutch etc. You can actually do it very easy without taking anything apart, takes about 10 min.

 

It looks to be an easy and quick swap, but my thinking on waiting 'til the oil change was that, due to the fact that the oil has been drained, I'd minimize the drippage that has been attributed to this job when the original is removed.