2013 GMC Yukon Denali - bad lifter?

Geotrash said:

I'll add my voice to those saying it's a collapsed lifter - most likely an AFM lifter on either 2, 3, 5, or 8 (The AFM cylinders).

You have a few options. There is a tool and trick to get it unstuck that works for lots of folks, for a while at least, until they can get in there and mechanically delete the AFM system.

Are you handy and want to tackle this yourself? If so, you've come to the right place. Many of us have done full mechanical or at least partial (electronic) AFM deletes on our trucks and will be happy to help you. If you want to have a shop do it, that's fine too, but it's time for a tow and plan on a $3-7K repair bill, depending on what they find and recommend for solutions.

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adrianne said:

What's the trick I need to try it on my yukon number 4 cylinder has a stuck lifter right now causing a cyclinder 4 misfire.

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