Q: the timing chain is making noise at startup what needs to be replaced to fix the problem?

There are many reports about this issue with your truck. I have access to IATN (International Automotive Technicians Network) and the consensus is everything on the front of the motor needs to be replaced. Which is a very, very large job. Even so, it doesn’t sound as though this repair is a good repair. As they don’t seem to stay fixed, as you have seen.

Timing chain rattle on start up is a common issue across all manufacturers. Some are worse than others. The best advice I can give you with the present state of your truck is to make sure the oil is changed as soon as the oil gets dirty. Not by mileage or time, but my pulling the dipstick and seeing if it is dirty in comparison to new oil. If it is, change it. Since your truck has 129,000 miles on it, there have already been a few oil changes. I know manufacturers are recommending longer than usual oil changes and this could be contributing to this issue. At this point I recommend running a can of sea foam in your oil with each oil change.

The reason timing chains can be noisy on start up is either the pressure in the oil charged tensioner is bleeding off, or there is extra slop in the chain system that the tensioner isn’t design to take up. Dirty oil can lodge debris in the tensioner that will keep the check valve open bleeding off oil pressure. Dirty oil will also contribute to excessive wear of the timing chain guides. There maybe be a design flaw in the tensioners that no one has figured out just yet.

If this only occurs during start up, it probably is more of an annoyance than a problem that will cause more problems. At this point it seems this is an issue the industry has yet to figure out. I recommend talking to several different repair shops to see if anyone has a convincing fix for this. If they can’t offer anything different than what he dealership has, I would speak with someone else.

I have personally replaced many chains on the larger displacement Ford motors, with success fortunately, but I haven’t had the opportunity to work on the 3.5L turbo. Their design is similar.

If you’d like a second opinion on this, one of our mobile technicians can come to your home and diagnose the noise firsthand for an accurate repair.