Fuel Pump Regulator

[YellowStones]

I have been having a ticking/tapping engine noise. No dash lights. Rough idle. Runs not so well.

Concerned it may be a lifter issue. Service visit has been scheduled.

Anyway, had a guy contact me on YouTube saying it sounds like it could be the fuel pressure regulator....says GM addressed this regarding 2014-2019 models. I have a 19 TB.

Anyone have any experience with this?

I went to autozone last night.....the part has to be ordered and is $250 - $350. Not cheap.

 

[Gearhead6873]

Mine's a 2020 TB 5.3, runs great and I've had no problems. But I do have a rhythmic tick at idle that can be clearly heard when standing next to the driver front tire. I bought my truck used, but still under warranty, so I took it to the dealer to have it checked since I was also concerned about a potential lifter problem. I was told it's the internal fuel pressure regulator (maybe he said fuel pump, I can't remember now) and that it was perfectly normal. You say yours doesn't run well though, so maybe not the same thing?

 

[YellowStones]

Yeah.

I feel like there is delayed response/acceleration.
Service visit yesterday at Chevy dealership. They looked at it for 2 hours...multiple test drives...was watching on GPS locator.

Went for test drive with service rep. when I dropped off. He said he heard it...plain as day.

I was told "head mechanic" couldn't find anything wrong with it. The power train warranty expired, so I was supposed to be charges $150 for the diagnosis.....after they called me to tell me they couldn't find anything wrong (during which the rep. repeatedly stated "the scanner wasn't throwing any codes, and we definitely don't think it's a lifter"), they called me a second time while I was en route to go pick it up just to tell me there would be no charge.

Noise is still there

I'm confused.


Might take to independent shop and have them take a jab at it........????


Feels like a fuel issue. I had a 96 Ford explorer in college that the fuel pump failed on the morning after we were up all night at the lake....yeah.....never forget that morning.....

 

[Baz]

Have you tried a different gas station just to rule out any fuel quality issues?

 

[mrcolieman]

These GDI engines have 2 sides to the fuel system. A low pressure system that uses an electric pump to get fuel from the tank (through a regulator that is computer controlled to be between 40-100PSI) to the high system; and a high pressure system that is a mechanical pump driven by the camshaft and can produce pressures up to 3,000 PSI depending on engine load (also computer controlled). The mechanical pump makes a normal ticking noise that can be heard at idle. If you don't have any codes or MIL I would agree with Baz... try a few tanks of high quality fuel from a top tier station and see if it makes a difference. If it doesn't, the order of operations for diagnosing any rough running engine is always good engine compression (mechanically sound), good ignition system and then good fuel system. It sucks to replace expensive fuel system parts just to find out you've had a bad valve or a failing coil pack to begin with. Of course both of those situations would be throwing codes and the MIL would be on...

Interesting note: the mechanical high pressure fuel pumps have seals that can fail and allow fuel to leak into the crank case. So for anyone out there listening, if you check your oil and it is overfull and smells like gas, you got a problem! Fuel in the oil will wash out the bearings and destroy the bottom end.(will also throw codes for running rich and long term fuel trim on a scanner will be in the negatives)

Good luck!

 

[YellowStones]

These GDI engines have 2 sides to the fuel system. A low pressure system that uses an electric pump to get fuel from the tank (through a regulator that is computer controlled to be between 40-100PSI) to the high system; and a high pressure system that is a mechanical pump driven by the camshaft and can produce pressures up to 3,000 PSI depending on engine load (also computer controlled). The mechanical pump makes a normal ticking noise that can be heard at idle. If you don't have any codes or MIL I would agree with Baz... try a few tanks of high quality fuel from a top tier station and see if it makes a difference. If it doesn't, the order of operations for diagnosing any rough running engine is always good engine compression (mechanically sound), good ignition system and then good fuel system. It sucks to replace expensive fuel system parts just to find out you've had a bad valve or a failing coil pack to begin with. Of course both of those situations would be throwing codes and the MIL would be on...

Interesting note: the mechanical high pressure fuel pumps have seals that can fail and allow fuel to leak into the crank case. So for anyone out there listening, if you check your oil and it is overfull and smells like gas, you got a problem! Fuel in the oil will wash out the bearings and destroy the bottom end.(will also throw codes for running rich and long term fuel trim on a scanner will be in the negatives)

Good luck!

Thanks. Appreciate the detailed response.

Had the truck for 100k miles. The tapping noise is new and can be heard inside the cab with windows up while driving. The noise increases and decreases with RPM. It is present when coasting with foot off accelerator as well. No codes. Had check engine light over a month ago....cleared it, never came back.

Took to dealership, they didn't say anything, wouldn't charge me for the diag attempt, and just gave me the keys back same day.

I removed and cleaned throttle body and MAF sensor....seems to be running better, but something still off....noise still present....tyranny has been slipping and jerking around in 1 st and 2nd a little too......tyranny was replaced at 86k

Something is up. So disappointed in this truck.

Regarding the fuel....I always run 91 Top Tier, and yes I have tried several different stations when filling up.

Does anyone know where scrader valve is to check fuel pressure?

Thanks

 

[YellowStones]

Also, spark plugs and new wires have been ordered

 

[Polk]

Thanks. Appreciate the detailed response.

Had the truck for 100k miles. The tapping noise is new and can be heard inside the cab with windows up while driving. The noise increases and decreases with RPM. It is present when coasting with foot off accelerator as well. No codes. Had check engine light over a month ago....cleared it, never came back.

Took to dealership, they didn't say anything, wouldn't charge me for the diag attempt, and just gave me the keys back same day.

I removed and cleaned throttle body and MAF sensor....seems to be running better, but something still off....noise still present....tyranny has been slipping and jerking around in 1 st and 2nd a little too......tyranny was replaced at 86k

Something is up. So disappointed in this truck.

Regarding the fuel....I always run 91 Top Tier, and yes I have tried several different stations when filling up.

Does anyone know where scrader valve is to check fuel pressure?

Thanks

I have a 2019 Trailboss with the 5.3-liter v8. I only notice the ticking noise when getting fast food or if I look into the front fender well. Like mrcolieman said, I think the noise from my truck is from the fuel system. I don't hear mine while driving though. If you take your truck on dirt at all, I would check your oil pan guard. I had rocks in mine which caused a loud rattling noise around 30-50mph.

 

[tbuss5831]

You will hear some ticking its normal. A lifter will sound like you have a little drummer boy in the engine compartment and can be checked by removing the valve cover and watching the rocker arms. I have heard pinging from using lower octane fuel. You can check fuel pressure with a scan tool but there is no shrader valve due to it being a high pressure system.

 

[Newfieboy58]

I have been having a ticking/tapping engine noise. No dash lights. Rough idle. Runs not so well.

Concerned it may be a lifter issue. Service visit has been scheduled.

Anyway, had a guy contact me on YouTube saying it sounds like it could be the fuel pressure regulator....says GM addressed this regarding 2014-2019 models. I have a 19 TB.

Anyone have any experience with this?

I went to autozone last night.....the part has to be ordered and is $250 - $350. Not cheap.

Yes iam having same issues took it to dealer fuel regulator/fuel pump parts ordered

 

[Gangly]

The high pressure fuel pump will create a ticking noise that is easily heard at idle. However, it should not be heard from the interior of the truck if the windows are up so I doubt what you are hearing is the fuel pump.

A ticking/tapping sound that raises and lowers with RPM's is usually valve train associated, but not always, and you would definitely have engine codes if you have a faulty drive train component since you would have incomplete combustion.

So knowing its not the fuel pump, and most likely not a valvetrain issue, you are narrowing down your possibilities which is a good thing. Something to check, and I have had this happen A LOT on other vehicles, is an exhaust leak at the header flange. An exhaust leak will often sound like a ticking or tapping noise, will raise and lower with rpm, never throw a code, and is easily heard from the occupant compartment. To check for an exhaust leak, first turn the engine on, then take a bottle of soapy water and spray it on the exhaust manifold flange where it attaches to the head, checking for bubble production. If you see any production of bubbles with the engine running, then you have an exhaust leak.

I hope you get it figured out, audible nuances drive me up the wall so I hope you come to a quick resolution.

 

[Newfieboy58]

The high pressure fuel pump will create a ticking noise that is easily heard at idle. However, it should not be heard from the interior of the truck if the windows are up so I doubt what you are hearing is the fuel pump.

A ticking/tapping sound that raises and lowers with RPM's is usually valve train associated, but not always, and you would definitely have engine codes if you have a faulty drive train component since you would have incomplete combustion.

So knowing its not the fuel pump, and most likely not a valvetrain issue, you are narrowing down your possibilities which is a good thing. Something to check, and I have had this happen A LOT on other vehicles, is an exhaust leak at the header flange. An exhaust leak will often sound like a ticking or tapping noise, will raise and lower with rpm, never throw a code, and is easily heard from the occupant compartment. To check for an exhaust leak, first turn the engine on, then take a bottle of soapy water and spray it on the exhaust manifold flange where it attaches to the head, checking for bubble production. If you see any production of bubbles with the engine running, then you have an exhaust leak.

I hope you get it figured out, audible nuances drive me up the wall so I hope you come to a quick resolution

Well just saying dealership did the testing they been on phone with the gm techs tried different tests with fuel system and the testing came up with fuel regulator tests were 1 test lower and one test upperside parts ordered see if it it's the problem

 

[Gangly]

Well just saying dealership did the testing they been on phone with the gm techs tried different tests with fuel system and the testing came up with fuel regulator tests were 1 test lower and one test upperside parts ordered see if it it's the problem

I hope they are right and you get your truck back in working order sooner rather than later. Let us know how it goes.

 

[YellowStones]

I hope they are right and you get your truck back in working order sooner rather than later. Let us know how it goes.

I'm getting some new codes. Few weeks ago it was a code for 'LF ABS solenoid/motor high Voltage" (forget specific code, scanner quoted the solenoid thing.....googled the code and it came back as a "yaw rate sensor" issue......

Last night got additional code (U0346) - possible fixes include wire harness repair (chewed up wiring around ECM) or replacing cam shaft position sensor.

still runs fine...I think....who knows...done taking it to dealership. Also get other codes about communication problems with gateway A, and ECM, TCM codes...but been that way since brand new. But the 2 I mentioned above are brand new......still sounds like 74 dump truck

I do know that ECM is located down there by the drivers side front upper control arm.

Read several GM bulletins about the 346 code....checked recommended fuses.....looked for wire wear/corrosion ect....could be there for sure, just haven't seen it yet.

I'm leaning towards exhaust leak at this point based on the sound, but with these codes popping up, now not so sure

 

[Gangly]

There was a documented issue with the wire harness chaffing around the driver's side wheel well, and with the multiple and various codes you are getting that is definitely something I would check. Good luck with figuring this out, I know it can be a headache.