2014 5.3 intense gas smell with no leak

[Zach Green]

I have a 2014 silverado with a 5.3 and 140,000 miles. I can't see a leak anywhere but I have a persistent and intense smell of gas in the cab and around the truck. Also when starting the truck it takes a good 25-30 seconds of cranking before it fires. Not sure if that related or not. I appreciate any help recieved.

[nqabigt]

top of fuel pump/fuel line rusted out probably

DO NOT DRIVE!!

[Zach Green]

That what I was trying to narrow it down to. The high pressure pump under the intake manifold right?

Edited December 3, 2023 by Zach Green

[nqabigt]

pump is in the fuel tank

[Zach Green]

Ok thank you. 

[mjm-1957]

The high pressure fuel pump is a known issue on those trucks. Intake manifold has to come off to replace also must replace two- one time use fuel pipes.They will have yellow stickers on them.The sound deadening cushion is probably saturated with fuel and should be replaced also.

[Zach Green]

So that's what I'm trying to narrow down. Is there a way to test if it's leaking before I remove intake manifold.

[ember1205]

3 hours ago, mjm-1957 said:

The high pressure fuel pump is a known issue on those trucks. Intake manifold has to come off to replace also must replace two- one time use fuel pipes.They will have yellow stickers on them.The sound deadening cushion is probably saturated with fuel and should be replaced also.

 

It's one single-use pipe that's required. There is a second line that's recommended to replace, but not actually required.

[ember1205]

3 hours ago, Zach Green said:

So that's what I'm trying to narrow down. Is there a way to test if it's leaking before I remove intake manifold.

 

Put an OBD reader on it and see if you have any pending or stored codes. If the O2 sensors are showing "rich" condition combined with LTFT showing significant reductions (double digits) under driving load, you could have a leaking HPFP. Another thing you can do is either pull the dipstick and smell for gasoline or change the oil and do the same.

 

If it's the HPFP, you're getting fuel leaking through the pump and directly into the engine. The fuel will contaminate the oil, reduce lubrication, and trick the O2 sensors into thinking you're running rich. If that's all happening, you'll actually be running lean AND have reduced lubrication of the moving parts in the engine so getting that pump changed as quickly as possible will be in your engine's best interest.

[Zach Green]

I checked the oil and there is no fuel. Also only code is a missfire on cylinder 1. I have a snap on solus.

[mjm-1957]

The long crank times are a clue. The pump is leaking externally and going , down the side of the bell housing . The smell of raw fuel in the cabin is a giveaway.  Put your scanner in live data mode and watch the desired  fuel rail pressure and actual fuel rail pressures. Turn the engine off and see how fast the rail pressure drops off. It should stay close to running pressure for quite a while. If it doesnt you better take the intake off and examine the pump before you have a fire.

[ember1205]

3 hours ago, mjm-1957 said:

The long crank times are a clue. The pump is leaking externally and going , down the side of the bell housing . The smell of raw fuel in the cabin is a giveaway.  Put your scanner in live data mode and watch the desired  fuel rail pressure and actual fuel rail pressures. Turn the engine off and see how fast the rail pressure drops off. It should stay close to running pressure for quite a while. If it doesnt you better take the intake off and examine the pump before you have a fire.

 

The HPFP would leak fuel into the engine and it would be something that could be smelled in the oil. If gas is leaking outside of the engine, I believe the injectors or the fuel rail itself would be the more likely culprit.

[mjm-1957]

I dont know where you are getting your information from. You can think what ever you want. I am trying to offer some advice to the original poster. I have been a line mechanic at a GMC Buick dealer since 1978 and may have slightly more experience then you do in these trucks.The high pressure pump can and does leak externally and also internally. The original poster already said no fuel in the oil so what does that tell you.Not a big deal to remove the intake and investigate before he has a fire and doesnt have to worry about a fuel smell.

[rlcole321]

I concur, removing the intake is fairly easy, leaning over the engine close to the sound absorption foam under the intake might revile the gas smell. And if the foam is saturated, then either the HP pump or lines are the culprit!