Engine hum/whine

22’s · January 14, 2019

I have a 2014 Silverado Ltz z71. So I’ve done a ton if reading on the noise I am hearing. It sounds exactly like a power steering pump going bad. But I know these trucks don’t have a power steering pump and from what I’ve read it’s the oil pump. My question, is there any sort of fix? It’s loud! And annoying! Bought a week ago and between this noise, the vibration and the mechanical vacuum pump I’m already considering getting rid of it.

damnthetorpedoes · January 14, 2019

Transmission pump? I know on some of these you can hear it at idle/low speeds.

22’s · January 14, 2019

Transmission pump? That’s a new one for me. Any more you can say about it?

Lsgun1 · January 14, 2019

It would sound like a hydraulic power steering pump low on fluid. It would change with engine RPM.

22’s · January 14, 2019

38 minutes ago, Lsgun1 said:

It would sound like a hydraulic power steering pump low on fluid. It would change with engine RPM.

That’s pretty much spot on for what I’m hearing. Any ideas on how to diagnose?

another thing I’ve notice that’s odd to me is oil pressure. Cruising around 70mph oil pressure is right about 40psi. When I stop for a light or stop sign, it drops down to about 15psi. Seems a little low to me.

damnthetorpedoes · January 14, 2019

Do you have the 6 speed? I think those have a dip stick, I know the 8 speeds do not. I would start by checking the trans fluid. How many miles? If you don't have service history it might be a good idea to get the fluid changed.

Where in MN are you?

22’s · January 14, 2019

52 minutes ago, damnthetorpedoes said:

Do you have the 6 speed? I think those have a dip stick, I know the 8 speeds do not. I would start by checking the trans fluid. How many miles? If you don't have service history it might be a good idea to get the fluid changed.

Where in MN are you?

It is a 6 speed 5.3L 67k for miles. I bought it from a dealer and they said they checked all that over. I guess I trusted their evaluation on the truck, that’s out the window now!

Im south of the twin cities about a half hour in Cannon Falls.

damnthetorpedoes · January 14, 2019

48 minutes ago, 22’s said:

It is a 6 speed 5.3L 67k for miles. I bought it from a dealer and they said they checked all that over. I guess I trusted their evaluation on the truck, that’s out the window now!

Im south of the twin cities about a half hour in Cannon Falls.

I would try talking with the sales manager at the dealership first. If that goes nowhere I would have an independent look over the trans. I used TSI in Richfield as they do a free drive test/diagnostic. They seemed pretty honest with me and just recommended a fluid change. It seemed to help on the Equinox (sealed unit with no dip stick). At 67k with an unknown history this might be a good idea anyway.

https://www.transmissionshopinc.com/

Keep in mind its pretty common to hear a slight transmission whine on these trucks because they are so quiet with stock exhaust.

dieselfan1 · January 14, 2019

Take it to TSI

Great shop no BS

At that mileage it's time to change the fluid anyways. I doubt it has been changed

Edited January 14, 2019 by dieselfan1

22’s · January 14, 2019

25 minutes ago, dieselfan1 said:

Take it to TSI

Great shop no BS

At that mileage it's time to change the fluid anyways. I doubt it has been changed

Are you talking about the one in Richfield also?

newdude · January 14, 2019

17 hours ago, 22’s said:

I have a 2014 Silverado Ltz z71. So I’ve done a ton if reading on the noise I am hearing. It sounds exactly like a power steering pump going bad. But I know these trucks don’t have a power steering pump and from what I’ve read it’s the oil pump. My question, is there any sort of fix? It’s loud! And annoying! Bought a week ago and between this noise, the vibration and the mechanical vacuum pump I’m already considering getting rid of it.

Perhaps some of that reading before purchase might have had some influence beforehand? Not trying to be a jerk, and sorry if I come off as one.

Quote

#14-06-04-004D: Various Engine Noises During Cold Start and Warm Engine Operation - (May 21, 2018)

Information For Why New Engine Technologies Are Generating Noises

The latest generation of full size trucks and utilities incorporate a new generation of technologies not previously seen in full size truck and utility applications. As a result these engines generate noises during cold start and during warm operation that owners of previous generation multiport fuel injection (MFI) vehicles may not be familiar with.

Direct Injection (DI) / High Pressure Fuel Pump / Fuel Injectors

The new Small Block Generation 5 engine family incorporates a new fuel system technology known as Direct Injection (DI). With DI, fuel is injected directly into the cylinder using a high pressure fuel system. DI provides many benefits in improving engine efficiency. In particular, DI improves power, torque, and most importantly fuel efficiency. This technology is included as standard equipment on all Generation 5 engines in the Small Block engine family which are the: 4.3L V6, 5.3L V8, and 6.2L V8.

The high pressure fuel system does have unique operating characteristics, in particular the noise emanating from the high pressure fuel pump can result in a subtle ticking noise that is apparent when the vehicle is idling. The sound is more evident when outside around the vehicle, when the hood is open or the vehicle is operated in a drive-through. 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 a normal characteristics of the DI high pressure fuel system.

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

Oil Pump Cold Start Rrrrp or Rasp

The oil pump design has changed from a gerotor gear type pump to a two speed vane type pump for fuel economy reasons. At temperatures at or below 32°F (0°C) or when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drainback. Upon startup the owner may hear a short Rrrrp or Rasp coming from the front of the engine. It is most often heard during a remote start. There is nothing wrong with the oil pump or oil system. No repairs should be attempted for this condition.

(SIDE NOTE: I wish GM would update this as the oil pump seems to almost always generate noise, regardless of temperature.)

The first two years of the K2 trucks are the ones with the bugs. Plenty of good trucks from those first two, but some bad ones out there.

Good luck.

22’s · January 14, 2019

2 hours ago, newdude said:

Perhaps some of that reading before purchase might have had some influence beforehand? Not trying to be a jerk, and sorry if I come off as one.

The first two years of the K2 trucks are the ones with the bugs. Plenty of good trucks from those first two, but some bad ones out there.

Good luck.

Not a jerk at all.

My noise I don’t think falls under the “various engine noises”.

The stuff I’ve read would of had a huge influence. I did some reading but nothing of this magnitude came up.

The first two years of the K2 are the ones I like better. The 16’s and up are ugly to me. But, lesson DEFINITELY learned.

BIGDOGx · January 15, 2019

18 hours ago, 22’s said:

Not a jerk at all.

My noise I don’t think falls under the “various engine noises”.

The stuff I’ve read would of had a huge influence. I did some reading but nothing of this magnitude came up.

The first two years of the K2 are the ones I like better. The 16’s and up are ugly to me. But, lesson DEFINITELY learned.

I have this issue on my 14 and it drives me crazy. Like you said the sound is best described as a early 1990's ford taurus steering pump whine as all taurus models had that issue and this sounds nearly identical to those sounds. My dealer has told me 3 times as the noise has only grown worse, that it is the fuel pump making the noise which i call BS as the noise is coming from up front in the engine bay. I think it's trans related but what do i know, the dealer just continues to tell me it's the fuel pump.

22’s · January 15, 2019

21 minutes ago, BIGDOGx said:

I have this issue on my 14 and it drives me crazy. Like you said the sound is best described as a early 1990's ford taurus steering pump whine as all taurus models had that issue and this sounds nearly identical to those sounds. My dealer has told me 3 times as the noise has only grown worse, that it is the fuel pump making the noise which i call BS as the noise is coming from up front in the engine bay. I think it's trans related but what do i know, the dealer just continues to tell me it's the fuel pump.

Exactly my thought when I noticed it, until I learned these trucks don’t have power steering pumps. I have heard a couple of different 14-15’s run and idle now and none are as loud as mine. Mine also changes on cold start up. It’ll be real loud then quiet down a bit till it’s brought up in rpm, then it’s very prominent. When mine quiets down I can hear the high pressure fuel pump and the noise I am hearing is definitely not that.

I am working on getting my into the dealer where I bought it(they included a 3 month 6,000 mile warranty) to have the noise(and a list of other things) looked into. If they give me the run around, I plan on just taking it where I choose and have the transmission fluid and filter changed.