Engine Tick - 2015 GMC Sierra 5.3

Jonty711 · August 7, 2018

This weekend I will try and pressurize the exhaust system and look for leaks around manifold and y pipe.

Jonty711 · August 19, 2018

So I haven’t had time to check for an exhaust leak. I drove to Detroit last week, 400km round trip. As usual, on the highway, no issue, but the marble noise at low speed under load.

I typically run 87 octane, so when I got back I filled up, but with 91 instead. Tank was half full.

what have I noticed? The marble noise has eased back and while present, is not half as bad.

This put me thinking. I basically now am running 89 octane. But probably have been running poor fuel leading to a knock issue.

this thread below sounds similar to what is going on with the majority of these trucks.

I’m still going to search for an exhaust leak next weekend, but I’m thinking this could be a knock sensor issue, that’s retarding a spark long enough, but not severe enough to trigger a CEL.

AdamGMC2017 · August 20, 2018

I've run a few tanks of premium and mid grade, and have noticed no difference. Also did a Sea Foam flush in the intake and the tank. No difference.

I don't believe it to be fuel detonation related.

My sound has been as bad as ever lately (even with the Sea foam and higher octane fuel). While towing my boat, it sounds like the engine is going to rattle through the hood. Loud enough for my oblivious wife to actually hear it. I was towing last weekend and had to make a hard stop. When I pulled away the sound had disappeared. Sounded like a normal truck for the rest of the drive home. I've also noticed that I can't heard the sound while accelerating during a turn, but when I straighten out it comes back.

I can't see how an intermittent sound can be caused by low octane fuel. Maybe the sound is always there, and I only hear it when something settles into place in the driveline and causes some harmonic vibration. Either way, it's very irritating. Might be time for some Dynamat all over the floor and firewall.

Anyone know how to get some actual GM people to look at these threads? I've seen them pop in on other forums and offer to "help". This seems like a big enough issue for them to be paying attention to.

jasinger · August 20, 2018

Been a while since I chimed in, mine has become more consistent, it is just about daily now. 400 mile road trip this weekend and listened to the tick the entire time, even my passenger in the front seat commented on it. Just hit 1 year of ownership with 12k miles

20165.3Eco · August 20, 2018

Yep, mine goes away around corners (Especially long on ramps). It can be made to disappear under hard acceleration in 1-2 gears (when I assume torque moves the engine the most). Hard stops cause it to be gone and return on a bump that moves the truck around a lot.

I have been to busy to get it into the shop but my Power Train warranty will be up soon so I am going to try and shoot for an appointment next week. Haven't had time to try any other diagnostics myself.

Truck sounds fantastic when it isn't ticking. I notice the GM reps are staying away from this thread.....Wonder why....

2016LTCC · August 20, 2018

The last few posts here are spot on with what I hear. My dealer said couldn't duplicate and is normal. I can put up with a lot but a loud ticking noise isn't something I feel I can live with. If I don't resolve this soon i will be moving to a ford or 2012-2013 chevy if I can find one.

Jonty711 · August 20, 2018

9 hours ago, AdamGMC2017 said:

I've run a few tanks of premium and mid grade, and have noticed no difference. Also did a Sea Foam flush in the intake and the tank. No difference.

I don't believe it to be fuel detonation related.

My sound has been as bad as ever lately (even with the Sea foam and higher octane fuel). While towing my boat, it sounds like the engine is going to rattle through the hood. Loud enough for my oblivious wife to actually hear it. I was towing last weekend and had to make a hard stop. When I pulled away the sound had disappeared. Sounded like a normal truck for the rest of the drive home. I've also noticed that I can't heard the sound while accelerating during a turn, but when I straighten out it comes back.

I can't see how an intermittent sound can be caused by low octane fuel. Maybe the sound is always there, and I only hear it when something settles into place in the driveline and causes some harmonic vibration. Either way, it's very irritating. Might be time for some Dynamat all over the floor and firewall.

Anyone know how to get some actual GM people to look at these threads? I've seen them pop in on other forums and offer to "help". This seems like a big enough issue for them to be paying attention to.

Sounds like a firewall steering boot failure!!

Spastik Monkey · August 20, 2018

I think GM doesn't want to get involved as I'm guessing they know the cause. I'd imagine the fix is probably expensive.

AdamGMC2017 · August 20, 2018

10 minutes ago, Jonty711 said:

Sounds like a firewall steering boot failure!!

My steering boot and connection to the firewall has been covered with sound deadener since May. Noise still there. It isn't that.

AdamGMC2017 · August 20, 2018

1 hour ago, 2016LTCC said:

The last few posts here are spot on with what I hear. My dealer said couldn't duplicate and is normal. I can put up with a lot but a loud ticking noise isn't something I feel I can live with. If I don't resolve this soon i will be moving to a ford or 2012-2013 chevy if I can find one.

Ticking drives me insane. I told my wife I was gonna do the same, basically trade in my truck for an old beater. She said "you have a beater now". At least the interior of my current truck is nice. Maybe some knobby tires will drown out some of the god awful engine sounds it makes.

Jonty711 · August 20, 2018

14 minutes ago, AdamGMC2017 said:

Ticking drives me insane. I told my wife I was gonna do the same, basically trade in my truck for an old beater. She said "you have a beater now". At least the interior of my current truck is nice. Maybe some knobby tires will drown out some of the god awful engine sounds it makes.

There's times I think I'm driving an old Singer sowing machine

Sierra Dan · August 20, 2018

2 hours ago, Spastik Monkey said:

I think GM doesn't want to get involved as I'm guessing they know the cause. I'd imagine the fix is probably expensive.

Maybe the fix is cheap....... it is the volume of repairs and dealer reimbursements that keeps them from chiming in.