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

[swathdiver]

Unless your motor was built before April 2005, it should not have a screen under the oil pressure sensor.

Have you pulled the valley pan to check the condition of the VLOM tower o-rings?

 

[carrmann]

Unless your motor was built before April 2005, it should not have a screen under the oil pressure sensor.

Have you pulled the valley pan to check the condition of the VLOM tower o-rings?

Not sure how to check that, but its a 2007 yukon xl 6.2. So I dont believe it was. Should I change the sensor anyways or nah?
I have not had the intake manifold off. Is VLOM dod/afm related? I don't believe I have any of that stuff, or would I still have it? I had to google VLOM to be honest, so I'm pretty clueless right now about that.
A friend suggested oil pump? That doesnt seem likely to me, but I really am unsure.

 

[Geotrash]

Not sure how to check that, but its a 2007 truck. So I dont believe it was. Should I change the sensor anyways or nah?
I have not had the intake manifold off. Is VLOM dod/afm related? I don't believe I have any of that stuff, or would I still have it? I had to google VLOM to be honest, so I'm pretty clueless right now about that.
A friend suggested oil pump? That doesnt seem likely to me, but I really am unsure.

Nice job on the pickup tube o-ring!

On the ‘07 6.2L the block is cast with the towers for the AFM system and they’re drilled with an oil port. But since GM elected to not use AFM on that engine, they used a flat valley pan with o-rings on the backside of it that seal the towers. Over time, the o-rings get hard and the valley pan bolts also lose their torque as they do, allowing oil pressure to bleed off. The fix is to either replace the valley pan or plug the towers with a plug designed for it, and at that point since you’re in there you can replace the oil sender.

But in my opinion your pressures are just fine.

 

[swathdiver]

Not sure how to check that, but its a 2007 yukon xl 6.2. So I dont believe it was. Should I change the sensor anyways or nah?
I have not had the intake manifold off. Is VLOM dod/afm related? I don't believe I have any of that stuff, or would I still have it? I had to google VLOM to be honest, so I'm pretty clueless right now about that.
A friend suggested oil pump? That doesnt seem likely to me, but I really am unsure.

Let me add to Dave's post. The very earliest Yukons and Escalades had L92 engines with AFM components installed but not active in the tune. Either way, the o-rings on the valley cover can be a source of oil pressure loss.

If the valley cover under the plastic intake is flat, your motor doesn't have AFM. Like I said, whether you have it or not, it can bleed off oil pressure if the o-rings for the towers are leaking. You first remove the intake manifold and then can access the valley pan cover. Get new gaskets for each due to age.

 

[carrmann]

Let me add to Dave's post. The very earliest Yukons and Escalades had L92 engines with AFM components installed but not active in the tune. Either way, the o-rings on the valley cover can be a source of oil pressure loss.

If the valley cover under the plastic intake is flat, your motor doesn't have AFM. Like I said, whether you have it or not, it can bleed off oil pressure if the o-rings for the towers are leaking. You first remove the intake manifold and then can access the valley pan cover. Get new gaskets for each due to age.

ok thank you, I will check that then next! Much preferred to crawling on the ground for 6 hours haha.

 

[carrmann]

Let me add to Dave's post. The very earliest Yukons and Escalades had L92 engines with AFM components installed but not active in the tune. Either way, the o-rings on the valley cover can be a source of oil pressure loss.

If the valley cover under the plastic intake is flat, your motor doesn't have AFM. Like I said, whether you have it or not, it can bleed off oil pressure if the o-rings for the towers are leaking. You first remove the intake manifold and then can access the valley pan cover. Get new gaskets for each due to age.

any chance that you know what hot idle in gear should be for this motor? I've read multiple different numbers. 550rpm seems low to me(verified with tech 2), but I'm also used to older engines (carb). Thanks!

 

[swathdiver]

any chance that you know what hot idle in gear should be for this motor? I've read multiple different numbers. 550rpm seems low to me(verified with tech 2), but I'm also used to older engines (carb). Thanks!

It's usually between 500-550, as low as possible for emissions purposes. The computer controls the idle based on many factors such as load, air temperature, transfer case position, the weather, etc.

BlackBear Performance usually raises the idle speed 25-50 rpms so that they idle better and to reduce some engines' tendency to stall when you let off the gas too quick.

Just like the older engines, a more aggressive camshaft will idle higher.

 

[carrmann]

It's usually between 500-550, as low as possible for emissions purposes. The computer controls the idle based on many factors such as load, air temperature, transfer case position, the weather, etc.

BlackBear Performance usually raises the idle speed 25-50 rpms so that they idle better and to reduce some engines' tendency to stall when you let off the gas too quick.

Just like the older engines, a more aggressive camshaft will idle higher.

Oh ok, well there goes that idea! Its at about 20psi idling in park when hot (about 600 rpms).
I'd rather get a tuner, as I will probably dabble with some mods on it after I get everything fixed (longtubes, cam, exhaust most likely).
Yessir, more aggressive camshafts pull less vacuum so they have to idle higher or brakes etc have issues.

I need a valley pan gasket, the VLOM o rings, and a intake manifold gasket. Any particular gasket brand I should go with, or stay away from? Or a part # for these, like a kit?
Does AlldataDIY have that info?

 

[Geotrash]

I need a valley pan gasket, the VLOM o rings, and a intake manifold gasket. Any particular gasket brand I should go with, or stay away from? Or a part # for these, like a kit?
Does AlldataDIY have that info?

New flat valley pan and gasket, GM 12598832

Be sure to replace the oil pressure sensor at the back of it as well.

 

[carrmann]

I'll be replacing the oil pressure sensor for sure while I've got it apart! Thanks Geotrash!

I found that my rear shocks are blown(air shocks), and while I've been exploring in the engine bay found that the front shock electrical? connectors are no longer connected to the front shocks (up at the top I'm assuming), and the front shocks have coil springs on them. I'm assuming the front shocks do Not come with coils so someone already converted the front to non air suspension?

Also found it doesn't have a front sway bar, and someone snapped the mount bolts off on the passenger side for the sways, so thats going to be a very fun fix!

 

[Geotrash]

I'll be replacing the oil pressure sensor for sure while I've got it apart! Thanks Geotrash!

I found that my rear shocks are blown(air shocks), and while I've been exploring in the engine bay found that the front shock electrical? connectors are no longer connected to the front shocks (up at the top I'm assuming), and the front shocks have coil springs on them. I'm assuming the front shocks do Not come with coils so someone already converted the front to non air suspension?

Also found it doesn't have a front sway bar, and someone snapped the mount bolts off on the passenger side for the sways, so thats going to be a very fun fix!

The front suspension is always coil spring on these trucks, even when you have air suspension in the rear. It’s possible that the previous owner replaced the front shocks with passive shocks and installed resistors to avoid the service suspension warning message. If you can snap a picture of the front strut cartridges, we can help you identify them perhaps.

I can’t imagine driving one of these without a front sway bar. That’s a big deal. Those bolts use the friction nut plate, so you may end up having to drill it out and change the threads with a tap. Sucks man, I’m sorry.

 

[carrmann]

that makes sense, I've seen conversion kits so assumed the springs were due to no ride control. I def have the light for service suspension(dont see any resistors in that harness at least). I've attached pictures to this post that you wanted to see. It seems to have had front/rear air suspension(I can see components indicating it did at least), especially since its a Denali.

I will be fixing the sway bar for sure. I assumed it needed front shocks and That was why it was so 'floaty' up front lol.

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.

 

[Dustin Jackson]

@carrmann Is it still stalling? If the stalling went away then @JB_TravelTech theory is correct

 

[carrmann]

@carrmann Is it still stalling? If the stalling went away then @JB_TravelTech theory is correct

It had not gone away as of when i replaced the oring. I haven't driven it long enough since to test if the oil pressure is the cause or not.

 

[Dustin Jackson]

@carrmann Your recent reported oil pressure readings are good so that should be plenty oil pressure for the VVT system to work with

 

[carrmann]

@carrmann Your recent reported oil pressure readings are good so that should be plenty oil pressure for the VVT system to work with

so if he is correct, it wont stall anymore. it didnt always do it without fail... so I need to drive it some to test it. It is not my daily, it will take some time before I can drive it long enough to test it.

 

[carrmann]

about to replace my exh manifold gasket, as it has a leak. looks like oil from valve cover has been leaking on it. I'm seeing posts about replacing valve cover and not just new gaskets/orings. Not sure it applies to me though? Going to be doing exh man gasket along with valve cover gasket (or new valve cover?).

 

[Dustin Jackson]

about to replace my exh manifold gasket, as it has a leak. looks like oil from valve cover has been leaking on it. I'm seeing posts about replacing valve cover and not just new gaskets/orings. Not sure it applies to me though? Going to be doing exh man gasket along with valve cover gasket (or new valve cover?).

It’s old enough that it probably doesn’t have the new valve cover design, I would buy a new driver side valve cover and a set of valve cover gaskets

 

[carrmann]

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

 

[Dustin Jackson]

Probably connectors from the factory air ride