P0302 and botched lifter valve job?

[DrEmmettBrown]

Hello all - I've been poking around this sight for a little while...first time poster. Thought I'd get the collective mind's opinion. I'll try and make this long story as short as possible.

 

Last year, just weeks after I bought the truck (2015 Silverado 5.3) had a collapsed lifter valve on the right side, dealer did repair under warranty. 

 

Fast forward to a few weeks ago, starting to get a hard misfire in the 2250-2700 range under load. Truck throws a P0302 (cylinder 2 misfire) of course truck is now out of warranty by a few months and miles. So I moved the coil pack, spark plug and spark plug wires all to different cylinders and still getting P0302 and now the hard misfire is getting worse down to 1500. 

 

I decide to tackle the injectors, and while I'm in there I might as while replace all 8. When I pulled the right side injectors there was no seal between the injector and the head, but they were there on the left side. I put I call into the dealer that did the lifter job, the tech tells me that he pulls the head without removing the injector rail- seems plausible. He tells me that these come from the factory without the seals, and the seals are only installed if the injectors are R&R. I have the carfax and I'm starting to smell BS now. I called the dealership the truck was at before me and was even able to get a gold of the previous owner and there is no record of any engine work, and owner says he never had any issues. 

 

So my question is, did this truck come from the factory with the seals on the left side, but not on the right?

Is it possible that there is some undocumented engine work to the left side injectors while the truck was under warranty?

Or did the tech fail to put the seals back in after the repair? If so would that cause an injector to go bad, or something else like a vacuum leak at the injector? They seem to be nothing more than dust boots.

If this is caused by a bad repair job, what recourse do I have with the dealership now that my truck is off warranty and I started the job on my own? The lifter repair was done less than a year ago and about 8,000 miles ago.

Sorry for such a long first post. Appreciate and responses

 

Matt

 

 

[JimCost2014]

Welcome to the site.

 

Pretty sure if the lifters were put in wrong you would have known very quickly, as they make a lot of noise when not happy.

 

Injectors are a known problem to fail, did not see the current miles on your truck listed.

[DrEmmettBrown]

Mileage is now at 56,000. Was 48,000 when the lifters were done.

 

I guess the title of my post is misleading. I'm not saying the lifter job was completely wrong, but curious why the injector boots (sorry if this isn't the right term) were not installed on the right side injectors. And if it is likely that oversight happened during the valve job or from the factory. And if it make a difference. 

 

Matt