2015 Silverado 5.3 Cold start noise

redwngr · February 8, 2016

See last paragragh:

New Engine Technologies and New Sounds

April 8, 2014

The latest generation of engine technologies found on the 2014 Corvette and 2014-2015 Silverado 1500, Suburban, Tahoe, Sierra 1500, Yukon and Yukon XL may produce some unfamiliar sounds during cold starts as well as during warm operation. The new engines include the 4.3L V6 (RPO LV3) (Fig. 10), 5.3L V8 (RPO L83), 6.2L V8 (RPOs L86 and LT1).

F10 4.3L V6

Fig 10

Direct Injection

The new small block engine family uses a Direct Injection (DI) fuel system. The fuel is injected directly into the cylinder using a high pressure fuel system, which improves power, torque, and fuel efficiency. The high pressure fuel pump can generate a subtle ticking sound that is apparent when the vehicle is idling. The sound is more evident when outside the vehicle, when the hood is open or the vehicle is operated in a drive-through environment. The sound may be more noticeable during a cold start, but lessens once the engine is warm. A slightly higher pitched clicking sound is the fuel injectors pulsing on and off under the high fuel pressures. These sounds are normal characteristics of the DI system.

Another operating characteristic is a slightly longer crank time, which is the result of the time required to build high pressure in the fuel system before the engine starts.

Oil Pump

The oil pump design on these engines is a two-speed vane-type pump. Its dual-pressure control enables operation at a very efficient oil pressure at lower rpm, and then delivers higher pressure at higher engine speeds.

At temperatures of 32°F (0°C) or colder, when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drainback. Upon start-up, a short rasp sound may be heard from the front of the engine. It is most often heard during a remote start. This is a normal condition.

tnchevy · February 8, 2016

The new trucks are built a bit heavier too though. The difference in frames alone is a big change. There was a definite increase in curb weight going from the gmt800 to the gmt900 and now the gmtk2xx platforms.

I had heard that they were made heavier but what is the reason for making them so? If it is for towing/haul weight then IMO they should leave that to the 2500 trucks. Most buyers of half tons use them for grocery getting or towing lighter weight campers and boats. I really like my 2014, especially the power of the 5.3, but I think GM had a great (but not perfect) truck in the 800 series. Wish they could have mated the current engine in the older 800 and called it a "classic" or something like that.

HondaHawkGT · February 8, 2016

I had heard that they were made heavier but what is the reason for making them so? If it is for towing/haul weight then IMO they should leave that to the 2500 trucks. Most buyers of half tons use them for grocery getting or towing lighter weight campers and boats. I really like my 2014, especially the power of the 5.3, but I think GM had a great (but not perfect) truck in the 800 series. Wish they could have mated the current engine in the older 800 and called it a "classic" or something like that.

The frame was boxed to match the new F150 frame. Then the torsion bar front suspension was dropped for the coilover setup. In 2014 they made the 9.5" axle standard on the V8 models (a BIG plus imo).

The truck might be heavier but I'm happy with the balance of fuel economy, weight, and capability. As much as I like the gmt800's I could never go back.

Exhausted · February 10, 2016

Heh, that's my video. Pretty much every truck does it. It's normal. Its a pump or something

So I listed to the video and thought I heard it but is yours making the "rattle"/"grind" noise on cold start after the truck has sat for awhile? It only lasts for a second or so but does not sound good.

They're saying it's the oil pump?

fondupot · February 10, 2016

So I listed to the video and thought I heard it but is yours making the "rattle"/"grind" noise on cold start after the truck has sat for awhile? It only lasts for a second or so but does not sound good.

They're saying it's the oil pump?

Nothing grinds or rattles on my truck. The sound in the video is just a pump turning on. I have over 31k miles on the truck and it's done it from day 1. Along with every single other GM half ton. I'm not worrying about it.

Direct quote from above:

"At temperatures of 32°F (0°C) or colder, when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drainback. Upon start-up, a short rasp sound may be heard from the front of the engine. It is most often heard during a remote start. This is a normal condition."

Edited February 10, 2016 by fondupot

BigBadSierra · February 10, 2016

Old engines needed to warm up and I think the new ones need to warm up even more than the old ones did.

I had a 3.6L in my previous SUV and it was way nosier in the morning that the 5.3 is.

GsBowtie · February 11, 2016

The sound I'm referring to is NOT a fuel pump. That sound is very ovbious after the guy first turns the key on. The rattle / rrrrp/ rasp or whatever you want to call it happens just after the engine fires.

My truck does that pretty much year round on the first start of the day or when I'm leaving work at night. I hope no long term engine damage is being done for those first few seconds there is no oil pressure. It sure sounds like VTC rattle to me, but I've never had one of these new engines apart yet. Sounds like metal on metal to me, but hopefully I'm wrong.

Edited February 11, 2016 by GsBowtie

Amuro · January 2, 2017

Thread is kinda old but I was searching for answers and kinda glad I'm not the only one with this issue or it's normal. Best way I can discribe the noise chirp on start up is a bad power steering pump/ air in the power steering pump chirping sound on a old car and I know these truck have electronic power steering system. My 2016 which is still New did it from the beginning and still does it now with 8k miles. But why did the 2017 5.3l loaner truck that I had for a week did not do the same noise... I was thinking about taking it in for this noise on start up but from what others are exp, it might be normal or is normal for these trucks.

brianj752 · January 9, 2017

I have a 2016 1500 Silverado 5.3. Since its been colder out (maybe 32 or colder), on cold start up there is a rhythmic loud tick/knocking sound until warm. It is a loud noise you can hear it 10 ft from the truck. It starts about 5/10 seconds after cold start up and once engine is warm goes away. This happens every time i start the truck if its cooled down since its been cold out. Have about 7400 miles on the truck. Brought to the dealer and they thought PIP5395A would take care of it, it didn't (they didn't bother letting the truck cool for hours and start to see if it fixed the problem either, winter here now). I'll bring it back in but wanted to post this to see if anyone has had the similar sound/issue and if so was it diagnosed and addressed? Not sure if its related with something in the trans but when I coast down to 20 from about 30 mph then press the gas to go the truck clunks and slams into 2nd? gear from 3rd? kind of worrisome. Not sure if I made the right decision to buy this truck...

Video link:

Thanks,

Brian

Edited January 9, 2017 by brianj752

Colossus · January 9, 2017

Seems more like something belt driven.

hirdlej · October 2, 2017

Brian, did you ever get this addressed or find out what it was? Or is this considered "normal operation"? I have a new 2017 with 3k miles on it doing the same thing. I sure dread going into the dealership to have my stuff looked at since it always comes back with a new scratch or ding. If it's normal I'll just let it be. Mine goes away after 10 minutes of driving and is fully warmed up.

I have a 2016 1500 Silverado 5.3. Since its been colder out (maybe 32 or colder), on cold start up there is a rhythmic loud tick/knocking sound until warm. It is a loud noise you can hear it 10 ft from the truck. It starts about 5/10 seconds after cold start up and once engine is warm goes away. This happens every time i start the truck if its cooled down since its been cold out. Have about 7400 miles on the truck. Brought to the dealer and they thought PIP5395A would take care of it, it didn't (they didn't bother letting the truck cool for hours and start to see if it fixed the problem either, winter here now). I'll bring it back in but wanted to post this to see if anyone has had the similar sound/issue and if so was it diagnosed and addressed? Not sure if its related with something in the trans but when I coast down to 20 from about 30 mph then press the gas to go the truck clunks and slams into 2nd? gear from 3rd? kind of worrisome. Not sure if I made the right decision to buy this truck...

Video link:

Thanks,

Brian

brianj752 · October 3, 2017

Accepted the noise as normal. Some 5.3's louder than others. Felt the clunk in drivetrain in a 2015 Silverado, so guess that's normal too. Time will tell.

hirdlej · October 4, 2017

FYI I brought my 2017 Sierra into the shop today to have an issue looked at with getting "steering assist reduced" at startup. Long story short, I talked to the tech who worked on my truck about the noise you were showing. He said the majority of the trucks do that and it's related to the DI pump on top of the engine. He said nothing is getting hurt or will fail related to that click. Anywho, I'll keep my ears open on mine. For some reason it didn't hardly make that noise today but the last few days prior it made that noise clear as could be. I wonder if it has something to do with oil getting to the DI pump or if the DI pump has a lifter on it that needs priming of sorts. I'm going to look into how one works since I have zero idea.

15_silverado · October 4, 2017

Brian, did you ever get this addressed or find out what it was? Or is this considered "normal operation"? I have a new 2017 with 3k miles on it doing the same thing. I sure dread going into the dealership to have my stuff looked at since it always comes back with a new scratch or ding. If it's normal I'll just let it be. Mine goes away after 10 minutes of driving and is fully warmed up.

My 2017 5.3L makes the exact same noise as in the video.

If you ever goes to the dealer to get this fixed, please let us know.

I too believe it has something to do with the high pressure fuel pump, but the question is, is how long will this pump last before it fails, because this noise can't be normal or good since all of them don't do it. My 2015 5.3 never made this noise.