Plugs dirty after 800 miles

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Foggy

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Good idea... watch your actual coolant temps.. The gauge is OK at best..
180* - 215* all shows up on these gauges at the 210* middle mark.. So don't trust it.

Short trips are not great... Oil does not get up to temp and gets dirty and full of moisture
very quickly... I'd do an oil change and add a catch can. Then drive for a several hundred miles
 
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bdbull

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Good idea... watch your actual coolant temps.. The gauge is OK at best..
180* - 215* all shows up on these gauges at the 210* middle mark.. So don't trust it.

Short trips are not great... Oil does not get up to temp and gets dirty and full of moisture
very quickly... I'd do an oil change and add a catch can. Then drive for a several hundred miles
Went into town today and the temp got up to a normal range. It was right at 210 on the gauge and the Torque app had it right around 194. Just checked my coolant and it appears to be a little low. I wonder if I have a coolant leak and that's what's causing the plugs to get dirty. I've read/watch Youtube videos before on testing for a coolant leak but I'll need a refresher if I decide to check that out.

I have a catch can on order, but probably won't get to it until this weekend.

Oil was changed about 1500 miles ago when I did the AFM deflector and oil pan gasket.
 
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bdbull

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Made a couple updates since I first posted. Installed the updated driver side valve cover with an oil change. (That was a whole other adventure.) Just installed a catch can as well. Will be out of town for the next few days in my wife's Tahoe so won't get to drive my truck until next week, though.
 
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bdbull

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Put about 150 miles on it with some interstate driving and everything seemed normal. The rough idle seemed to be a little better, or I could have just been hoping it was better. But, just when things seem to be going well, the proverbial :poop: hits the fan.

Coming back from an appointment across town just now and all of a sudden traction control and stabilitrack lights go nuts. Truck seemed to be driving fine at highway speeds, but lower speeds were very rough. I made it home and popped the hood to see if I could see anything obvious. Sounded like there might be a vacuum leak or something leaking air, but I couldn't tell for sure. Unfortunately my bluetooth OBD reader is in my wife's car so I can't check the codes until she gets home. Once the engine cools down, I may go remove the catch can and replace it with the OEM PCV hose to see if the "air leaking" sound goes away. Hopefully it's just that simple, although I don't know why it would work for a few hundred miles and then all of a sudden not.

Hopefully it's not related to the valve cover work that was done recently.

It never freaking ends.
 

Geotrash

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Put about 150 miles on it with some interstate driving and everything seemed normal. The rough idle seemed to be a little better, or I could have just been hoping it was better. But, just when things seem to be going well, the proverbial :poop: hits the fan.

Coming back from an appointment across town just now and all of a sudden traction control and stabilitrack lights go nuts. Truck seemed to be driving fine at highway speeds, but lower speeds were very rough. I made it home and popped the hood to see if I could see anything obvious. Sounded like there might be a vacuum leak or something leaking air, but I couldn't tell for sure. Unfortunately my bluetooth OBD reader is in my wife's car so I can't check the codes until she gets home. Once the engine cools down, I may go remove the catch can and replace it with the OEM PCV hose to see if the "air leaking" sound goes away. Hopefully it's just that simple, although I don't know why it would work for a few hundred miles and then all of a sudden not.

Hopefully it's not related to the valve cover work that was done recently.

It never freaking ends.
Sure sounds like an intake manifold leak to me. I'd yank that thing out and check for cracks, then put it back on with a new gasket set if none are found. You can do the whole thing in 2 hours or less. You can put a new oil pressure sensor and screen in while you're in there. And you can take that stupid plastic piece at the back of the manifold that makes changing the oil pressure sensor such a PITA, and throw it in the trash.
 
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bdbull

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Checked all plugs and wires, everything seated properly. Changed back to the OEM PVC hose. The hissing sound was gone but the truck was still running like crap. I've seen a few videos where a catch can produces a hissing sound because of the hoses used so I'm guessing that's what's going on there.
Sure sounds like an intake manifold leak to me. I'd yank that thing out and check for cracks, then put it back on with a new gasket set if none are found. You can do the whole thing in 2 hours or less. You can put a new oil pressure sensor and screen in while you're in there. And you can take that stupid plastic piece at the back of the manifold that makes changing the oil pressure sensor such a PITA, and throw it in the trash.
I'm just a YouTube mechanic so I have no clue about the intake manifold. I'll search on YouTube for videos on that, but if you have any offhand that'd be great. As for the oil pressure sensor and screen, I've changed those at least 4 times now so I'm pretty familiar with that job. (Thanks GM)
 

Geotrash

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Checked all plugs and wires, everything seated properly. Changed back to the OEM PVC hose. The hissing sound was gone but the truck was still running like crap. I've seen a few videos where a catch can produces a hissing sound because of the hoses used so I'm guessing that's what's going on there.

I'm just a YouTube mechanic so I have no clue about the intake manifold. I'll search on YouTube for videos on that, but if you have any offhand that'd be great. As for the oil pressure sensor and screen, I've changed those at least 4 times now so I'm pretty familiar with that job. (Thanks GM)
I don't have any YouTube videos for it, but I'm sure they're out there. There's really no trick to it. The only PITA is getting the fuel rail separated from the hose, but all you need to do it in 30 seconds is to drain the pressure in the fuel rail using the Schrader valve on the passenger side of the fuel rail, and to use the right GM quick connect line tool on the fitting itself. Easy peasy.
 
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bdbull

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Wife got home with the code reader so I checked it out. Only code it has is P0300 so not much help there.

Been watching a lot of videos about stuck lifters due to high mileage and AFM so I decided to take a look. No stuck lifters on the driver side. But...of course when putting the valve cover back on one of the non-stripped out bolt holes from my previous issue stripped out as I was torquing it down. So, I'm throwing in the towel and taking it to the shop in the morning...the same shop that already fixed the first two stripped out bolt holes. Gonna cut my losses and not even attempt to look at the lifters on the passenger side. FML
 

Caligirl

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Following 'cause we are dealing with VERY similar crap with our 2007 Tahoe. Also do short drives that barely warm anything up. We are just starting down this rabbit hole, so will share what we findas we go. Already had vacuum test and fuel trim readings done... plugs the next project because our mechanic friend thinks plugs, wires, coils may be issue (but WHY did they fail so soon?). Husband was gonna do them himself, but not like older trucks and needs special tools or hands that can turn into stretch material to get into little tiny areas...
 
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bdbull

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Does this offer any useful information? I don't know what this might mean other than it thinks there's something wrong in the fuel system, whatever that means.
 

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