2007 Yukon XL and I smell gas under the hood

[superhawk]

Hi Everyone,

I have a 2007 Yukon XL SLT. This odor... it is intermittent. Almost as if I smell it at the very edge if my ability to detect the odor. Not like the gas is 'pi**ing' into the engine bay, but where should I be looking if I am detecting an odor of gas whatsoever? What side, what hoses carry it and can pop off, anything you can think of.

Thank you,
Evan

 

[MichaelSE]

In my case with another vehicle, gas smell under the hood turned out to be an exhaust manifold leak. Does your engine also have a slight ticking or puffing sound that follows rpm? Sometimes the crack in the gasket/manifold itself can be so small that the noise is masked by other engine noise.

The hard lines running to the injectors are gasoline lines, which I believe are pressurized and can't really be serviced. It could also be something with the evap system, but I'm not too familiar with the evap system on these vehicles, perhaps someone else can chime in.

 

[superhawk]

Thank you for the reply. Actually my truck has been ticking but that is almost definitely the lifters that I've been quoted at literally "thousands" of dollars to fix. From your answer it sounds like the issues may be related. The ticking is there Michael, as you suspected. But I am told that fixing the dead lifter (s?) is going to involve the head gasket and the exhaust manifold gasket. Just as you said. Thank you.

 

[MichaelSE]

Hmmm, in that case, I would get a mechanic's stethoscope, place the probe on the manifold, and then place the probe on the valve cover, or as close to the lifters as you can get, and determine where the ticking is the loudest. You're at a disadvantage since lifter tick and manifold leaks can sound so similar. Wish I could help more on the gas smell... but good luck.