Does Locking Out the Cam Phaser Cause Engine Damage?

If you’re here, you probably have a bad cam phaser and you’re worried about damaging your engine by installing a cam phaser lockout kit. We’re here to tell you that you have nothing to worry about. Locking out the cam phaser will not damage your engine.

How a Cam Phaser Lockout Works

The cam phaser is a part in the variable valve timing system that shifts from one position to another to adjust your engine’s valve timing. The cam phaser in Ford V8 engines is prone to failure due to the way it’s designed. If it fails, your engine will experience a bunch of problems. You could replace the cam phasers with another set. But it is an expensive job, and the repair is still not reliable. You can also chose to lock out the cam phaser, which is an inexpensive and more reliable solution.

Failing cam phaser

This GIF shows how a failing cam phaser can shake and rattle around as you drive. Please note that the GIF is not 100% technically accurate - the phaser looks a little different than our drawing. Still, this is a good representation of what's going on when a phaser starts to fail and make noise.

To lock the phaser in one position, you put a small aluminum block into the empty space between the phaser vane and the sprocket body. A good cam phaser lockout kit has a metal block that’s designed to fit into the space.

Don’t be alarmed when the “check engine” light comes on after locking the cam phaser. It’s just because the ECU notices that the cam timing is always fully advanced. Tuning the ECU with a programmer will turn off the light. Another benefit of tuning is a smoother ride. We recommend using the programmer with a cam phaser lockout.

(Read more into detail about how cam phaser lockouts work.)

Locking Out the Cam Phaser is Basically Turning Back the Clock

Ford began putting cam phasers in V8 engines to implement variable valve timing and increase fuel economy. The cam phasers adjust the cams to vary the valve timing. Before this, the cams were simply installed into the standard factory position. This provided fixed, "advanced" timing for optimal power. Variable timing allows the cam (and thus valve) timing to be retarded when cruising to optimize fuel economy. Cam phaser lockouts simply lock the cam into the advanced timing position. Basically, by installing a lockout, you're just turning back the clock a few years to a time when engines were more reliable.

Failing cam phaser

This GIF shows how our cam phaser lockout works. Instead of shaking or rattling back and forth, the phaser is locked into position with a spacer (shown in red).

Of course, locking out the variable valve timing system means you're losing some fuel economy. The mpg drop is minor. The loss in mpg is better than spending several thousand dollars to replace a faulty cam phaser(s) and associated parts. Especially when the new phasers may fail again in a few years. On the bright side, your cam will be locked in the advanced timing position, which optimizes your engine’s performance.

You Must Lockout or Replace the Cam Phaser


If the phaser were to continue to knock/tap, all the vanes inside the phaser would eventually break. That can lead to reduced oil pressure in the block, which in turn would lead to severe engine damage. If you replace the cam phaser, you have to worry about the new cam phaser failing.

The main goal of installing a cam phaser lockout is to solve the problem. With one, the odds that you’ll have to worry about a broken cam phaser again are greatly reduced.

If you're thinking about getting a cam phaser lockout kit, here’s a comprehensive buyer’s guide that has all the information you need in one place.