Engine Tick - 2015 GMC Sierra 5.3

[Jonty711]

So got under the truck last night with a plastic mallet. 

 

Nothing seems to be loose.

 

Today went for a drive to try and define the parameters that set it off. 

 

I noticed that I can make the noise happen in v8 mode too, but the frequency has doubled over the v4 noise. 

 

I was able to get the truck to maintain velocity and rpms and switch from v4 to v8 and noticed the difference.

Edited July 15, 2018 by Jonty711

[20165.3Eco]

Yeah, it just sounds louder in V4 because the frequency is less drawing you to the noise more. Mine doesn't even need to warm up to make the noise. I did it less than 1/4 mile from our lake house this weekend running across the landing. 

 

I have found that mine is usually quietest in the morning (cold or at operating temp). The road I drive that takes me to my highway commute is smooth and 55 mph. Truck is quiet as a mouse until you hit the first jarring bump on the on ramp. Then it varies in noise level all the way into work on the highway. Seems like after the engine sits all night and "settles" in the mounts (or the offending part settles) it is quiet until disturbed. 

 

It almost has to be fuel system related because of the direct link to throttle position and that the frequency changes while in MDS (4 injectors aren't being used during V4). 

 

I was yanking around on the fuel return and supply lines under the truck yesterday, they have a fair amount of motion to them. I am going to try and zip tie those into a different position to see if it changes anything. I am also going to ratchet strap the engine with some downward pressure on both sides to see if that goes in line with the bumps/hitting the brakes hard symptom. 

[ChristopherDB]

Mine is not directly related to throttle position. It is linked to RPM. If I'm at a high RPM and let off the throttle to slow down the ticking noise continues even off the throttle and slows down as the RPMs lower.

[20165.3Eco]

Mine will do that at RPM as well pending how loudly it is currently acting. Its extremely throttle position related at lower rpm. 

 

That's how I found out you could mash the brakes and make it go away. I dropped the gears manually the other day when it was super loud. 

 

I also tried to turn the truck off while in a high gear to see if the noise went away but the programming on this truck immediately unlocks the TQ and the engine stops. Other trucks I have had would keep the TQ locked if you just turned the key to accessory then they didn't need to be started again, just turn the key back to run position. 

[cmillerr]

Hi, so my 2014 5.3 L83 truck at 38k miles still ticks just like a lot of guys here, but I have upgraded the air intake, Bigger 6.2 manifold, ported stock heads, DOD delete kit, new 660 lifters springs and  trunnion kit, custom cam, headers with side exhaust and it’s still ticks but it’s more pronounced under load(AC on). bumps and hard turns can make it stop but soon comes back. Next for me would be new oil pump or  vacuum pump. 

[20165.3Eco]

Would these throw codes if you went for a short drive with the vacuum pump disconnected ? 

 

Things that are isolated to divers side only are fuel lines/vac pump.

[20165.3Eco]

Would these throw codes if you went for a short drive with the vacuum pump disconnected ? 

 

Things that are isolated to divers side only are fuel lines/vac pump.

[Jonty711]

3 hours ago, 20165.3Eco said:

Would these throw codes if you went for a short drive with the vacuum pump disconnected ? 

 

Things that are isolated to divers side only are fuel lines/vac pump.

Kinda dangerous driving with the vac pump disconnected.

[20165.3Eco]

Plenty of private property to cruise around on. 

[Jonty711]

1 minute ago, 20165.3Eco said:

Plenty of private property to cruise around on. 

I would think it would throw a code. Let us know if you find anything. 

[20165.3Eco]

Will do. My co worker has had very good service from another dealer in town. Last effort I’m going to have that dealer take a look at the truck in 2 weeks before my warranty is up I still own it then. After they can or can’t fix it then I’ll dive back into working on it. 

 

Thw truck is so pleasant to drive when it’s quiet it’s a shame it makes these noises. 

[Jonty711]

47 minutes ago, 20165.3Eco said:

Will do. My co worker has had very good service from another dealer in town. Last effort I’m going to have that dealer take a look at the truck in 2 weeks before my warranty is up I still own it then. After they can or can’t fix it then I’ll dive back into working on it. 

 

Thw truck is so pleasant to drive when it’s quiet it’s a shame it makes these noises. 

I get ya. It’s 98% perfect, it’s just a couple of little things that take the joy out of driving it. I have 1 year left on warranty.

[20165.3Eco]

It will do it in 4 or 8 mode. Light acceleration or holding speed is most noticeable. Mine can be beautifully quiet for long periods of time until you hit a bump that moves the engine around then it will start making the noise. Stopping long distances and taking off lightly from a stop sign or light usually makes the sound go away again until you hit a bump. 

[Jonty711]

Interesting development. So this evening, I go for a small blast, and park up and leave the truck running. After 2 to 3 minutes of idling, the truck starts making the a noise similar to the under load tick, and sounds like water sloshing around. 

 

Sorry it it was hard to describe and only lasted 10 seconds.

[Flowernems]

Has any light come to this situation yet love how the Denalis are sold as having a quite cab. I can say in park running it is very quite