The Unexplainable, Unresolved issue an expert LS builder and Dealership can't figure out

[AZCreeker]

The repair shop tells me its most likely due the carbon build up from the direct injection.
We will see.
if not he will also inspect injectors, and check rich/lean/emission at tail pipe.
I really hope they can figure it out, I love this truck, just want to have the smell gone.
if successful, I'll have them install a catch can, can you guys recommend the most popular option?

 

[gooffeyguy]

A bad catalytic converter/s?

 

[iamdub]

The repair shop tells me its most likely due the carbon build up from the direct injection.
We will see.
if not he will also inspect injectors, and check rich/lean/emission at tail pipe.
I really hope they can figure it out, I love this truck, just want to have the smell gone.
if successful, I'll have them install a catch can, can you guys recommend the most popular option?

All you really need with a catch can is a good baffle setup. The expensive ones are functionally no better or worse than the cheap ones, for the most part. I like the $18 one on Amazon that has recently been discussed in the "Get a catch can before any other mods" thread. Add a stainless scrubber pad and you should be good to go, especially since your GenV shouldn't be passing as much oil as many GenIVs.

 

[AZCreeker]

All you really need with a catch can is a good baffle setup. The expensive ones are functionally no better or worse than the cheap ones, for the most part. I like the $18 one on Amazon that has recently been discussed in the "Get a catch can before any other mods" thread. Add a stainless scrubber pad and you should be good to go, especially since your GenV shouldn't be passing as much oil as many GenIVs.

a 18$ dollar one sure sound better than the UPD dual ones I see for 300$

 

[iamdub]

a 18$ dollar one sure sound better than the UPD dual ones I see for 300$

The only time you may need a fancier one, such as the dual valve unit from UPR, is if you're boosted. All you're doing on an LS engine is scrubbing ("filtering") a single, one-way circuit. There are crappy catch cans that basically rely on gravity to let the oil droplets fall out of suspension. The more filtration media you have (within reason- you don't wanna choke down the flow too much), the better. I have a $100 catchcans.com one on my Tahoe that works great and even better once I added more coalescing (filtering) media (stainless scrubber pad). I saw recently where a member took it a step further and modified his to hold one or two extra scrubber pads. His modifications didn't look like they'd hamper the airflow anything significant and I'll be copying his idea one day. I bought the $18 one for my brother's truck and added the stainless pad. I don't see how it would be any less effective than my $100 one or any other one of a higher price but same design. The ONLY drawback I saw to it was that it only had a 3 ounce capacity. I consistently drain 3 ounces out of mine every 5K miles. My brother drained maybe 1/2 a teaspoon out of his at a 3K mile change. His intake is dry on the inside so his motor ('05 5.3- Gen3) just isn't passing much oil at all through the PCV system. I'd expect your Gen5 to be an improvement over my Gen4 and not pass much oil. But, there's no laws against draining the catch can between oil changes (At every fill-up? Bi-weekly? Monthly?) until you get an idea of how long you can go between drainings. You can drain it and pour the oil right back into the motor.

This is the one I got off Amazon:

https://www.amazon.com/gp/product/B07JQKHW9W/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1


And this is where/how I added the scrubber pad:

 

[Tk59194]

Here is the UPR unit. I very much liked that it came with factory hose fittings. Didn't mind spending the extra cash considering how much i paid for the vehicle.

 

[Rocket Man]

Damn direct injected engines, they seem to have had their share of issues when they first came out. Hope you get it figured out and find someone worthy of the ediblearrangements.com gift basket because those things are awesome. The fruit not the injectors.

 

[GTNator]

I confess, I didn’t read all 47 posts above, only you’re first post and recent update. I know you said you think it’s coming from the tailpipe... you also said it’s a sweet smell? To me it sounds like antifreeze or a radiator leak. If it’s dripping onto you’re exhaust it may manifest itself the way you describe. It can also make its way into you’re cabin through the vents.

If I totally off base cause I didn’t read the other post, please ignore. Good luck.


Sent from my iPhone using Tapatalk

 

[Dooba]

I bypassed my 04 Yukon’s heater core a couple months back because ethylene glycol (antifreeze) in vapor form was leaking into the cabin. It had a sweet smell to it.

I bypassed the heater core and the smell went away instantly.

I’m not saying you have a faulty heater core or anything, but I do agree that its most likely an antifreeze leak somewhere.

 

[AZCreeker]

I figured that its for sure a raw gas smell and its coming from the tail pipe.
I originally thought it was coming from around the side of the truck but I think its just the downturn tail pipe hitting the ground then going everywhere.
the reason I am sure is because if i remote start the truck, cold or already warmed up, I smell it right away putting my nose next to tail pipe.

The shop is done with my car and telling me to come see if I can still smell it.

I will update findings. If any.