3.5L Ecoboost Timing Chain Replacement

The 3.5L EcoBoost is great engine with a few problematic complaints as of late. These engine that comes buried inside the F150 as well as the Taurus SHO has been seeing a little growing pains concerning the timing chain. I mean that statement very literally - the timing chains are stretching causing all sorts of problems. A stretching chain starts out to cause a few drivability issues, maybe a little bit of noise, then escalates into a full blown teardown due to bent valves. I love these 3.5L EcoBoost engines, but this is definitely an issue.

Have no fear though, as this problem can be remedied with a new timing chain. I can't say for sure that a new chain won't stretch again, but it will for sure fix your issues in the meantime. Changing the timing chain on a 3.5L Ecoboost isn't nearly as bad as you might think. Even with the twin turbo engine having an impressive three timing chains, three chain tensioners, four chain guides, four camshafts, and 24 front cover bolts - at least the front cover area is rather open and easily accessible even when the 3.5L is stuffed inside your F150. I feel sorry for you Taurus SHO guys.

Eventually, I will divide this article up into a few pages explaining removal procedures for each model. There are going to be a few tools you will need to complete such a task like changing your timing chain. A basic selection of tools will get the job done along with the addition of a few specialty tools.

Camshaft Holding Tool
3 Jaw Harmonic Balancer Remover
(Torx Plus) TP55

The Torx Plus socket is used for removal of the camshaft sprocket bolts. It is very different from a regular Torx socket. The use of the wrong tool will likely strip the bolt head out leaving you with a pretty significant issue. The puller is pretty standard to remove the harmonic balancer, and the camshaft holding tool holds the cams in the right spot for setting the chains. Obviously using the correct tools makes the job easier, but I will explain later that you can complete this job without the holding tools.

Be sure you know which bank is which. The "left" bank is the one that is on the drivers side or on the front of the engine in a front wheel drive application. Always think of it as if you were sitting in the drivers seat looking forward out of the window. Now, onwards to the step by step.