I got here as fast as I could - '04 Suburban Z71
- Thread starter tbisaacs
- Start date
tbisaacs
Adventurer
Taking advantage of the holiday weekend to catch up on some nags:
Rebuilt parking brake using AC Delco kit. The shoes were okay but the adjustors were seized up-so it would work for a few weeks and then stop.
Finally got around to changing my plugs and wires. #1 and #8 require some serious contorting and a whole lot of swearing. The plugs appeared to be original
Replaced my PCV valve & vent hose. Hoping this is the source of a mild oil consumption issue. I keep getting a whiff of oil from the driver's side after the car is warm.
Also, played in the snow with the family & dog. I love this rig more and more each day:
Rebuilt parking brake using AC Delco kit. The shoes were okay but the adjustors were seized up-so it would work for a few weeks and then stop.
Finally got around to changing my plugs and wires. #1 and #8 require some serious contorting and a whole lot of swearing. The plugs appeared to be original
Replaced my PCV valve & vent hose. Hoping this is the source of a mild oil consumption issue. I keep getting a whiff of oil from the driver's side after the car is warm.
Also, played in the snow with the family & dog. I love this rig more and more each day:
rayra
Expedition Leader
You'll probably find the weep holes in the baffle on the inside of the driver side valve cover are clogged with crud. It's the structure that feeds the PCV system. When those holes clog up you start ingesting oil. You'll loikely find all sorts of oil residue pooled in the bottom of the central chamber of the intake. I did a write-up and pics here (along with other common Vortex / LS / LM engine issues) -
http://www.expeditionportal.com/for...Vortec-Guys!-Sierra-pickup-Suburban-Yukon-etc
http://www.expeditionportal.com/for...Vortec-Guys!-Sierra-pickup-Suburban-Yukon-etc
tbisaacs
Adventurer
You'll probably find the weep holes in the baffle on the inside of the driver side valve cover are clogged with crud. It's the structure that feeds the PCV system. When those holes clog up you start ingesting oil. You'll loikely find all sorts of oil residue pooled in the bottom of the central chamber of the intake. I did a write-up and pics here (along with other common Vortex / LS / LM engine issues) -
http://www.expeditionportal.com/for...Vortec-Guys!-Sierra-pickup-Suburban-Yukon-etc
I remember reading this. How hard is it to take the valve cover off? Do I need to remove all the coil packs etc?
Thanks!
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rayra
Expedition Leader
The coil packs are all mounted on a plate, it's a few bolts to remove the whole row in one piece. More difficult bit is disconnecting the fuel injector connectors without breaking their plastic clips. But I don't recall if that was necessary to remove just the valve cover, it may not be. I was pulling the whole intake manifold / fuel rail setup off as well, so didn't really notice / recall if the injector wiring interferes with just a valve cover removal.
Just pull the plug wire ends off the coils, unplug the single wiring loom connection for the coils, and IIRC free the fuel injector wires from the two C-clips holding their loom. It's really pretty easy to do. They've done a nice job designing these motors so subsystems can be removed or serviced with having to dismantle a lot of stuff. Then it's the four bolts of the valve cover itself and it will come off easily. The gaskets are inexpensive and widely available. But if you are wanting to just look in there to see if those weep holes are clear you can generally re-use that same gasket. Just don't pry it out of the valve cover or hit it with any solvents, or else the rubber will expand and it will be difficult to get it crammed back in its groove.
Just pull the plug wire ends off the coils, unplug the single wiring loom connection for the coils, and IIRC free the fuel injector wires from the two C-clips holding their loom. It's really pretty easy to do. They've done a nice job designing these motors so subsystems can be removed or serviced with having to dismantle a lot of stuff. Then it's the four bolts of the valve cover itself and it will come off easily. The gaskets are inexpensive and widely available. But if you are wanting to just look in there to see if those weep holes are clear you can generally re-use that same gasket. Just don't pry it out of the valve cover or hit it with any solvents, or else the rubber will expand and it will be difficult to get it crammed back in its groove.
tbisaacs
Adventurer
I replaced my lower lenses today with some new Depos. The old ones were leaking and starting to mildew on the inside. Huge difference:
My turn signal / flashers were starting to flake out so I replaced the flasher unit. As a bonus, this one eliminates hyper flash in LED bulbs so I switched out my turn signals. Big difference in brightness.
My turn signal / flashers were starting to flake out so I replaced the flasher unit. As a bonus, this one eliminates hyper flash in LED bulbs so I switched out my turn signals. Big difference in brightness.
tbisaacs
Adventurer
I tightened my britches and replaced my intake manifold gaskets today to address a CEL. Special shoutout to Rayra's super helpful thread.
I was surprised to find a Fel-pro gasket in there already. But for whatever reason, I still had a vacuum leak. I was also relieved to find new knock sensors.
Like Rayra, I found a bunch of oil in my intake. Like, a lot of oil:
I got everything cleaned up and reassembled. Mission accomplished, no codes (or left over parts
)
I was surprised to find a Fel-pro gasket in there already. But for whatever reason, I still had a vacuum leak. I was also relieved to find new knock sensors.
Like Rayra, I found a bunch of oil in my intake. Like, a lot of oil:
I got everything cleaned up and reassembled. Mission accomplished, no codes (or left over parts
)Yeah, awesome job. Rayra's write ups are dandy! After Christmas I am going to do some much needed maintenance on my z71. Swapping all new coils, plugs and wires in....and doing the TB/MAF cleaning, as well as check the oil in the intake situation. mine has probably turned to crud at this point.
tbisaacs
Adventurer
The plugs and wires are a bear. Get yourself a spark plug boot puller or a pair of 90 degree needle nose pliers.
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rayra
Expedition Leader
yep, that's the downside of 100k iridium / platinum plugs, the boots and the plugs themselves are frozen in place when it's time to change them. I was quite worried I'd tear the threads in the aluminum heads, when I changed my plugs. Ironically I put anti-seize on the new plugs, but I'll likely never need to change them again. I'm only putting about 6k mi/yr on my Sub.
When I recently did the timing belt replacement on my neighbor's Tundra I had the same concern, they'd never been out as far as he knew, at 140k+ mi. They bound up as soon as I started turning them out. So I worked them back and forth a 1.4 turn or more, shot some penetrating oil down there to get into the threads. Problem is you get some carbon buildup on the protruding end of the plug and that carbon immediately jams in the plug threads. Really concerned about galling / damaging the threads in the aluminum head. So it was slow tedious work, working the oil into the threads and turning that carbon into mud so I could clear things out.
When I recently did the timing belt replacement on my neighbor's Tundra I had the same concern, they'd never been out as far as he knew, at 140k+ mi. They bound up as soon as I started turning them out. So I worked them back and forth a 1.4 turn or more, shot some penetrating oil down there to get into the threads. Problem is you get some carbon buildup on the protruding end of the plug and that carbon immediately jams in the plug threads. Really concerned about galling / damaging the threads in the aluminum head. So it was slow tedious work, working the oil into the threads and turning that carbon into mud so I could clear things out.
tbisaacs
Adventurer
Thank you, you are very kind. I still plan on leveling it once I get shocks.
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