Anybody ever heard of such weirdness?

I have an 09 Silverado Z71 with the 5.3

Yesterday on start up there was slight ticking sounding like it was coming from the driver side of the engine. After starting toward home, the check engine light comes on. Nothing noticeably wrong, no power loss or anything; just a ticking sound that increased in speed with increase in RPM of the motor.

Today I made a Uturn and the truck tells me low oil pressure. Make one more stop before I was going to take it to the shop and now everything has stopped. The ticking is gone and the check engine light is off.

What in the actual heck is going on?

If your truck has the active cylinder management system, then the most likely cause would be a lifter that was causing the noise. They will set trouble codes. Check the code that was stored in the computer and that will tell you a lot. Lots of issues with active management systems! Be sure and keep your oil changed religiously!!!

Truck definitely has AFM (and I hate it!)

Oil is always changed regularly. Doesn't seem oil is the issue. Checked the stick and it was good.

AFM is one of the top reasons why I got rid of my last silverado. Couldn't stand the "clunkiness" of the truck.

I've heard nothing but bad things about the Silverados that have AFM.

I have a 2011 with AFM. Not the biggest fan of it, but haven't had any issues with it either.

I have talked to several people who work on them and they indicate oil is a problem with them and you should change your oil at max 5k and use an oil that meets the dexos specs. I run mobile one in mine. It has 50k miles on it and has don't fine so far. I used to drive it as a daily driver, for the past 15-20k it has been a designated tow/ranch truck and still going good. Hope I don't have any issues with it. If I do I believe I will have a crate motor put in that doesn't have the AFM and run it into the ground.

For future reference if a warning that said low oil pressure came up I would turn it off!

sometimes the oil pressure sender on these trucks will [censored] out and cause the gauge to freak out and set the check engine light. afm uses a input from that sensor so be careful.

I had the same thing on a 2007 Suburban LTZ. After several dealership visits and misdiagnosed solutions, they ended up replacing all the rods/pistons (~$3000) in engine work. After about 10 months, the symptoms returned. I traded it in on a new Ford. Chevy knows about this problem as it's happened to a lot of owners ( research this on all the Chevy forums ) and they won't fix it. I complained, escalated to district service rep for Chevy only to be told .. " we'll give you $2500 off the purchase of a new one"..... IMO, Chevy quality went to sh.t between 07-12 when they had to get bailed out by the government.

Google " Chevy oil pressure loss, smoking" and see how many hits you get.

I hope for your sake that you have something less expensive to fix, but it didn't turn out pretty for me.

One other simple thing to check.. Go get an oil change! A bad oil filter can cause similar symptoms.

The problem had went away (along with the light).

Well lucky for me it just came back on.

Being that its only an 09 and under 65k, gonna take it in and let them figure it out.

I don't understand why AFM would cause this problem? Doesn't Dodge do the same thing with the hemi?

No doubt there are some lemmons out there. GM as well as all the other can have and do make them. I believe that a lot of failures are caused by owner/operators neglect/driving habits etc.

I had an 09 with the 5.3 AFM and got the low oil pressure warning 3 times. The first time came around 30K and the dealership found nothing wrong. The second time came around 75k, the dealership did something to "fix" it. About 100 miles later it came back on. The third time they said the oil pressure relief valve was sticking open, and it seemed to have solved it. The warning would come on soon after getting up to highway speed, so AFM could have been a reason.

If you drive in manual mode (M5) AFM is not activated.

X2