DRKHORS
Well-Known Member
Thanks for the info!Sorry for the late reply! Yeah, I've had a lot of experience with the tensioners as of late. My 2019 A10 had the chirping noise at hot idle, 2k rattle, and did not have the lift off rattle, which is the sound in question.
I bought and installed mmr's new timing chain tensioners which prominently introduced the lift off rattle. Comparing the design of these tensioners with those of the factory, I noticed the stock tensioners uses a more aggressive mechanical limiting system while mmr's can be compressed by hand, but use a small inlet in the back with a rubber seal, and revised internals to comply with Ford's tsb for the chirping noise. Their design edge is clearly hydraulic. If you were to try mmr's tensioners, I would suspect your lift off rattle to be louder than it is now.
In conclusion, what I noticed was a louder lift off rattle that subsides when the car warms up, no chirping noise, and a 2k rattle that has substantially subsided. If I had to guess, the 2k rattle comes from more than one source as I can still slightly hear a noise from the engine that is subtle, and sounds nothing timing system related.
I wish I could say if the lift off rattle introduces longevity issues. I personally compensate for it with smooth throttle use until the car is up to temp.
I wonder if there was a tensioner design change from gen 2 coyotes to gen 3, and what would have led ford to make such a change? My gen 2 mustang doesn't experience this, but my gen 3 f150 does...
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