My 07 Denali XL 'build'/Check Engine Lights/Questions

[carrmann]

changed out exhaust manifold gasket, plug wires, valve cover to new style valve cover/gasket.

drove it about an hour today, lowest I saw oil pressure hit was about 13psi in gear/idling at about 550rpm. still see close 35-40 psi at about 1100 rpm cruising

going to do the intake manifold/vlom/valley pan gaskets/orings this weekend hopefully.

update: forgot to mention. zero stalling, stumbling etc that I've seen before with the engine at lower oil pressure.

 

[Geotrash]

anyone have any input on those front shocks, or what goes behind the fuse box in the engine bay? @Geotrash

Sorry I missed this. The service suspension indication is most likely due to the PO putting in passive shocks, and since I don't see any resistors on those connectors, seems reasonable.

And I don't know what that connector is for but it's present on mine and connected. It looks like the wiring for the suspension might go through it but I couldn't trace it out for sure in the dark.

 

[carrmann]

Sorry I missed this. The service suspension indication is most likely due to the PO putting in passive shocks, and since I don't see any resistors on those connectors, seems reasonable.

And I don't know what that connector is for but it's present on mine and connected. It looks like the wiring for the suspension might go through it but I couldn't trace it out for sure in the dark.

I got Alldata diy and from what I've seen in there that 1 large connector seem to be a suspension relay. the wire next to it is the one in my photos i've posted that looks melted. Thats probably why it doesnt have active air anymore.
Is the rear air/front air tied together? Or do they operate independently? I'd like to use the rear if possible as I plan on towing a small boat/rv, but if I cant use the rear air I'll survive. I'm guessing I'll have to do a post in suspension for help with that stuff.

 

[Geotrash]

I got Alldata diy and from what I've seen in there that 1 large connector seem to be a suspension relay. the wire next to it is the one in my photos i've posted that looks melted. Thats probably why it doesnt have active air anymore.
Is the rear air/front air tied together? Or do they operate independently? I'd like to use the rear if possible as I plan on towing a small boat/rv, but if I cant use the rear air I'll survive. I'm guessing I'll have to do a post in suspension for help with that stuff.

There is no air suspension in the front. Only magnetic ride.

 

[swathdiver]

Any idea what is supposed to be behind the fuse box in the last picture? Seems something was hooked up there, havent found any good pictures that identify it.

Pretty sure that is for the heated washer fluid that was recalled. Do you have that button between your power outlets under the HVAC controls? You may have 3 to 5 buttons on those early cars.

Use GM OE parts whenever possible. Drill out those busted swaybar bolts and if you get lucky can save the threads, if not, helicoil or put in a bigger thread. There's a nut welded to the top of the bracket. They get really corroded up north and snap off easily since the heads are only 10mm, BTDT!

You're going to want a Tech-2 or similar to get this thing in top form again.

 

[carrmann]

There is no air suspension in the front. Only magnetic ride.

oh! maybe I can get the air compressor/air ride to work then.

 

[carrmann]

Pretty sure that is for the heated washer fluid that was recalled. Do you have that button between your power outlets under the HVAC controls? You may have 3 to 5 buttons on those early cars.

Use GM OE parts whenever possible. Drill out those busted swaybar bolts and if you get lucky can save the threads, if not, helicoil or put in a bigger thread. There's a nut welded to the top of the bracket. They get really corroded up north and snap off easily since the heads are only 10mm, BTDT!

You're going to want a Tech-2 or similar to get this thing in top form again.

I'm planning on replacing the swaybar/swaybar bolts. Right now theres nothing there at all lol, just the busted bolts. BTDT as well, I'm from up north. Love living down in the south, where my 16 year old vehicle with 170k miles isnt a rust bucket lol. I just took my exh manifold bolts out with a simple ratchet, zero issues.

You convinced me in another thread to get one lol. I dont really know how to use it sadly! Just basic diagnostics so far.

 

[carrmann]

Replaced the valley pan and vlom orings(original ones were quite flat), intake manifold gasket, oil pressure sensor. Zero change with my oil pressure when hot at an idle.

Not sure what else is left other than trying a quart of lucas. Oil pump i guess. Doesn't seem like it would be that to me with 35 to 40 psi at about 1200rpm. Maybe bearing issues? Can't hear any bearing noises though, a tiny bit at first start up(but I've heard other similar engines do the same)

 

[carrmann]

both my 'fresh air' pcv valve hose, and my 'dirty air' pcv valve hoses are cracked etc. The dirty air one i can actually hear sucking/blowing air, if I fiddle with it it stops. I seem to be able to find the 'clean air' pcv one pretty easily online.
The dirty air one I am struggling to get a part # for. IS this the correct part #? 12611592

 

[Geotrash]

both my 'fresh air' pcv valve hose, and my 'dirty air' pcv valve hoses are cracked etc. The dirty air one i can actually hear sucking/blowing air, if I fiddle with it it stops. I seem to be able to find the 'clean air' pcv one pretty easily online.
The dirty air one I am struggling to get a part # for. IS this the correct part #? 12611592

Looks right to me. Same as is on my ‘07

 

[swathdiver]

You convinced me in another thread to get one lol. I dont really know how to use it sadly! Just basic diagnostics so far.

Just poke around through each of the menus to see what they do, being careful not to make any changes unless you are sure of what you're doing. I learned mine while the kids were at volleyball practice! When you are diagnosing a problem and following the shop manual, it takes you step by step through it too.

 

[carrmann]

Just poke around through each of the menus to see what they do, being careful not to make any changes unless you are sure of what you're doing. I learned mine while the kids were at volleyball practice! When you are diagnosing a problem and following the shop manual, it takes you step by step through it too.

I've been playing with it some. But there is a lot of stuff, and I don't know all of the acronyms etc haha. I've gotten some of it down. But there's quite a bit more I need to learn.

Best tuner that I can use on the truck? I'd like to eventually get a tune for it, but for now just so I can bump up the idle a little bit (100 rpm). I dont want to mail out the pcm etc, so something that I can make small adjustments with(like idle rpm), and then if I do cam/headers/nocats etc get an emailed perf tune.

 

[Geotrash]

I've been playing with it some. But there is a lot of stuff, and I don't know all of the acronyms etc haha. I've gotten some of it down. But there's quite a bit more I need to learn.

Best tuner that I can use on the truck? I'd like to eventually get a tune for it, but for now just so I can bump up the idle a little bit (100 rpm). I dont want to mail out the pcm etc, so something that I can make small adjustments with(like idle rpm), and then if I do cam/headers/nocats etc get an emailed perf tune.

HP Tuners – Home

HP Tuners is the leading diagnostic and calibration solution for vehicle performance with the latest MPVI3 interface and VCM Suite software.

www.hptuners.com

 

[carrmann]

replaced my pcv clean/dirty lines. seems to have helped with my idle issues (would hang a little when driving). they were cracked pretty bad and leaking a lot of air.

 

[carrmann]

Pretty sure that is for the heated washer fluid that was recalled. Do you have that button between your power outlets under the HVAC controls? You may have 3 to 5 buttons on those early cars.

Use GM OE parts whenever possible. Drill out those busted swaybar bolts and if you get lucky can save the threads, if not, helicoil or put in a bigger thread. There's a nut welded to the top of the bracket. They get really corroded up north and snap off easily since the heads are only 10mm, BTDT!

You're going to want a Tech-2 or similar to get this thing in top form again.

Photo of the buttons. I believe your are correct. Button doesn't do anything. That's what the disconnected wires under-hood go to?

 

[carrmann]

Put new plugs in today. It was wayyyy over sure. Average gap on them was .080"! Pass rear plug was a little difficult to get at, but removing the wheel well liner made it pretty easy.

Found it has a broken exh manifold stud (front one) on driver's side.... Bummer!

Next up is driver side abs wheel sensor. Then im going to fix or replace the front seat, neither one works lol.

 

[j91z28d1]

front driver side, at least on my truck would be the easiest to get to. mine broke the rear drivers side. little worse but the clamp thing seems to be sealing it well. worth 20$ not to have to pull the manifold for a while.

the tend to suck air and mess with the o2 readings, might be worth moving that up the list.

 

[carrmann]

front driver side, at least on my truck would be the easiest to get to. mine broke the rear drivers side. little worse but the clamp thing seems to be sealing it well. worth 20$ not to have to pull the manifold for a while.

the tend to suck air and mess with the o2 readings, might be worth moving that up the list.

clamp thing?

 

[Fless]

clamp thing?

 

[carrmann]

View attachment 400577

thank you. the 917-107 seems like what I would need(pretty neat too!), but does not show it as fitting the 6.2 for 2007.

does not seem to be leaking from the broken bolt location however (pass side front bolt).