New to me 2011 Yukon XL Denali

[jdwood1111]

Background:
Hi everyone. My name is Jordan and have been a honda and acura guy most of my life but I recently purchased really clean 2011 silver Yukon XL Denali with 92k miles on it. One scratch on the rear passenger bumper and not another single scratch or dent anywhere! Everything on the interior works perfectly without issues and drives great! I bought it from a dealer who provided a 60day 2k mile warranty and after I identifying a trans cooler line leak and my mechanic finding a oil cooler line leak, they actually took the truck back and had both fixed no questions asked! This impressed me since it was not a extremely large dealer. This is a second vehicle for my family of 6 (4 little ones all 7 and under and no twins). My wife drives a 2011 odyssey and I have a work car.

Truck History:
The carfax shows only one large service record showing front ball joints were replaced, plugs and wires, brake fluid exchange, new tires balanced and alignment. I have identified the rear rotors appear to be new and everything else seems to be in line. So far I have installed Range AFM device per info on this forum, an Airaid intake tube, AEM dry filter and cleaned the throttle body during that installation. I also just flushed the power steering fluid via the dry turning of the wheel method with a hose which went well. I currently have 2qts of Dexron 6 ATF for the transfer case and 5qts of AC Delco Syn 75w90 handy for the front and rear diff to do as soon as I get a free day. So my only questions and concerns are now the following:

-Any other maintenance items I should take a look at? I did see the front brake pads will need replacement soon and the lower shock bushings are quite warn but the truck rides fine for now. I will most likely replaced the brakes with centric as that has been my go to for a while now.
-Transmission was shifting hard from 2 down to 1 but is a little smoother with the Range device which i attribute to the 4cyc to 8cyc timing. However, just yesterday it slipped slightly when trying to accelerate from i think 3 to 2, may have been 1 to 2. It was quite hot and the AC was on as well. I was planning on doing the trans service and filter myself as i am pretty handy but this may be a little more then i want to do in my driveway and got a quote for $285 from a reputable AAMCO place to drop the pan and do the fluid and filter. Trans temp always are quite low from what I have looked at.
-Unfortunately, it seems the oil cooler lines did not completely stop a leak as I still have a small amount of oil accumulating at the known rear engine and transmission. I looked inside the bell housing cover and it appeared to be mostly dry so hopefully not the rear main seal. I cannot see if its the intake cover or the oil pressure unit but was thinking of trying to replace the sensor JIC. My pressure is mostly above 40 when starting and driving around except at hot idle, it drops to around 28-30 or so which I believe is normal? I did try to tighten a couple of the oil pan gasket bolts and the bell housing bolts but have not checked it again since. It has not left anything on the ground at all only a little wet here and there.

Otherwise, I hope this truck last me quite awhile as I really enjoy the 6.2L motor and AWD!

Thank you,

Jordan

 

[doc5339]

Congratulations on the Denali and welcome to the forum!

 

[mrpeterclark]

Nice!

 

[Doubeleive]

heater hose's & T's at the firewall, radiator.
primarily due to age, the hose's and/or the T"s are prone to breaking after years of getting hot/cold the plastic gets brittle.
plastic sides of the radiator will crack
again these are things that just happen due to age and it's just a preventative maintenance thing not a emergency
inspect the air ride system and operation, these shocks typically wear out starting around 85k for this generation
check all over the engine (visually inspect and feel) for any wire harness that may be sagging or rubbing and re-secure them or adjust as needed, over time they can rub on other parts and chafe or rub thru damaging the wires.
that's about it, other things can sometimes need attention are hvac actuators, seat heaters.
a techII clone can come in handy down the road for troubleshooting any thing else that may crop up
the 6l80e's have a weak torque converter and may eventually need to be addressed this issue seems to rear it's head around 120k-165k, they can of course last longer it just depends, but when it goes it takes the pump with it. just something to be aware of if it ever starts shifting weird.

 

[swathdiver]

Welcome Jordan. Run the maintenance schedule under Severe Service to keep the fluids clean. Get a Tech-2 so you can properly work on this. Unless the parts are not available anymore, use GM OE or ACDelco Professional/Gold parts whenever possible, same for the brakes.

 

[jdwood1111]

Thanks for the responses all! I appreciate the feedback. I will look into the radiator and hoses, etc.! The AMMCO guy I called today said the exact same thing as Wes indicated about the torque converter going and taking the pump with it. He stated he would test drive the truck and see what he thinks and it would be about $325 for fluid, pan, filter and swapping out the transfercase fluid I give him (same as ATF but I already bought it). Hoping it doesn't need anything else. Trying to scheduling something for next week. Should I remove the Range device prior to taking it just from a drivability standpoint? It shouldn't matter but figured just in case maybe.

 

[Doubeleive]

Thanks for the responses all! I appreciate the feedback. I will look into the radiator and hoses, etc.! The AMMCO guy I called today said the exact same thing as Wes indicated about the torque converter going and taking the pump with it. He stated he would test drive the truck and see what he thinks and it would be about $325 for fluid, pan, filter and swapping out the transfercase fluid I give him (same as ATF but I already bought it). Hoping it doesn't need anything else. Trying to scheduling something for next week. Should I remove the Range device prior to taking it just from a drivability standpoint? It shouldn't matter but figured just in case maybe.

range device is fine, you might like a canned tune or a blackbear tune much better though. if the trans is shifting fine I wouldn't fret about it and just enjoy driving it, that's just a heads up if it act's up down the road.

 

[Geotrash]

Thanks for the responses all! I appreciate the feedback. I will look into the radiator and hoses, etc.! The AMMCO guy I called today said the exact same thing as Wes indicated about the torque converter going and taking the pump with it. He stated he would test drive the truck and see what he thinks and it would be about $325 for fluid, pan, filter and swapping out the transfercase fluid I give him (same as ATF but I already bought it). Hoping it doesn't need anything else. Trying to scheduling something for next week. Should I remove the Range device prior to taking it just from a drivability standpoint? It shouldn't matter but figured just in case maybe.

I replaced the torque converter (TC) in my 2012 proactively to prevent this problem from happening. I worked with a well-reviewed local transmission shop to source a TC from one of their trusted suppliers that has a billet housing and a stronger lockup clutch, but still has the factory stall speed. Out the door with a new rear main seal and new fluid/filter I think it was $1300. Fair deal.

 

[jdwood1111]

I read up on blackbear and would definitely like to pursue that but the $100 for the range device off Facebook market place to curb things was worth it!

Dave, I like the proactive approach on doing the TC along with the rear main seal at the same time since that may be my issue. I still think its worth doing the fluid and filter for now since its $325 and may resolve the issue and buy me some time. That does seem like a fair deal!

 

[jdwood1111]

I replaced the torque converter (TC) in my 2012 proactively to prevent this problem from happening. I worked with a well-reviewed local transmission shop to source a TC from one of their trusted suppliers that has a billet housing and a stronger lockup clutch, but still has the factory stall speed. Out the door with a new rear main seal and new fluid/filter I think it was $1300. Fair deal.

How many miles did your truck have on it when you replaced the TC?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Very nice find.

 

[donjetman]

131k miles when I proactively replaced mine 3.5 yrs and 44k miles ago.

 

[Geotrash]

How many miles did your truck have on it when you replaced the TC?

About 114,000

 

[jdwood1111]

So I drove the truck again since I haven't in a while and got under it. There is a slight leak still coming from somewhere at the joint between trans and motor as before but when I pop the cover off the bell housing it seems dry inside (hopefully not rear main) and I do not see oil coming down from somewhere up top. If I had to guess I would think its the oil pan gasket at this point but again, it is very mild right now. In wanting to tighten up the bolts slightly, I was unable to get to the bolt shown the picture below due to a black piece of plastic bolted to the block. Does anyone know what this is? Can I remove the bolt on the right side holding it to the block, move it away to then torque the circled oil pan bolt down a little?

 

[Geotrash]

So I drove the truck again since I haven't in a while and got under it. There is a slight leak still coming from somewhere at the joint between trans and motor as before but when I pop the cover off the bell housing it seems dry inside (hopefully not rear main) and I do not see oil coming down from somewhere up top. If I had to guess I would think its the oil pan gasket at this point but again, it is very mild right now. In wanting to tighten up the bolts slightly, I was unable to get to the bolt shown the picture below due to a black piece of plastic bolted to the block. Does anyone know what this is? Can I remove the bolt on the right side holding it to the block, move it away to then torque the circled oil pan bolt down a little?

Yes and yes, or try a 12-pt socket as it should be thinner wall and will fit in there - at least mine does. Also that's not much of an oil leak but I would bet that it's coming from either the o-ring on the plug at the bottom left of your circled area, or the gasket for the aluminum part where the oil cooler lines come out against the engine block. Both are common leak points.

 

[jdwood1111]

Yes and yes, or try a 12-pt socket as it should be thinner wall and will fit in there - at least mine does. Also that's not much of an oil leak but I would bet that it's coming from either the o-ring on the plug at the bottom left of your circled area, or the gasket for the aluminum part where the oil cooler lines come out against the engine block. Both are common leak points.

Thanks! That’s what I thought. I did try a 12 point and still wouldn’t fit. The picture was after I had always wiped the oil off so I’ll take a picture of the leak next time I run it and get under there but it wasn’t that bad. The oil cooler lines were just replaced so I don’t think it’s coming from there but what is the o-ring you mentioned? What is that going to? It really just seems to be wet around the lower half of the engine to trans joint and maybe slightly higher on the driver side. Maybe the oil pressure sensor gasket.

 

[jdwood1111]

So I finally had time to do the front and rear diffs and transfer case! Transfer case seemed quite red still and may have been done more recently than I thought. Gives me high hopes for the transmission. Front and rear diff seemed like they were original as they were black sludge.

Used all ac AC delco fluids and didn’t really run into any snags which was nice! Everything seems good and just waiting for my wife to get back from using the truck and make sure nothing is leaking. Only thing I forgot to do cause I was in a hurry was I put the rear pan gasket on completely dry so I hope that’s ok. I meant to lube it a bit so I hope it doesn’t leak but the gasket was in good shape.

I also removed that plastic plate mentioned previously and snugged down the two rear oil pan gasket bolts too while I was under there.

Overall pretty happy with how clean the truck was under there. Not much rust which is great!

 

[jdwood1111]

Wife got back the other day and no leaks and then I drove the truck around a lot yesterday and did not notice anything leaking upon inspection after! I do still get a small amount of residual at the same rear engine-to-trans so I guess I will try and inspect the oil pressure sending unit with a mirror per some research and maybe the valve cover gaskets as I do not know what else it could be. I will definitely let it ride. Now I just need to figure out the trans if I am going to to myself or have some one do it. I may just wait til the fall when its a bit cooler and tackle it myself with a buddy and save the money. Oh and I will need front brake pads soon otherwise hope everything stays good.

Also, not sure I noticed if it was doing this before I slightly tightened the oil pan bolts but the oil pressure once hot will stay a hair above 20 PSI at idle and then shoots up to around 37-38 on throttle and a little more above 40 PSI when I really get on it. Its around 50-60PSI on cold start up. Everything I have read seems to indicate this is normal but just figured I would verify these pressures.

Lastly, with the range device I am only seeing 12.5-14 MPG riding around town with very little highway. Before Range I was seeing 14.5-15.5 MPG so definitely a small reduction there. I read some people get an improvement but I am certainly not seeing that with my current round town driving. Going to try and save for a blackbear tune but that may be a while away unfortunately!

 

[jdwood1111]

Afternoon All!

So I was reading another post where some one stated they ran the Range AFM Disabler and then once they took it out their lifter got stuck. Is this something to be concerned about at all? Would it be good practice to take out the Range device every once and a while to allow the AFM to engage to keep things lubricated (forgive my exact understanding of how the internals work)? I have only had it in and driven the truck for a few hundred miles since installing it but wanted to pose the question after reading this. Realistically, I will never do a full DOD delete and as much as I would love a BB tune, 4 kids and life will probably prevent me from spending the money on it. Therefore, am I safe to continue using the Range constantly or, a removal and run it a bit and replace?

Thanks!

 

[Dustin Jackson]

Afternoon All!

So I was reading another post where some one stated they ran the Range AFM Disabler and then once they took it out their lifter got stuck. Is this something to be concerned about at all? Would it be good practice to take out the Range device every once and a while to allow the AFM to engage to keep things lubricated (forgive my exact understanding of how the internals work)? I have only had it in and driven the truck for a few hundred miles since installing it but wanted to pose the question after reading this. Realistically, I will never do a full DOD delete and as much as I would love a BB tune, 4 kids and life will probably prevent me from spending the money on it. Therefore, am I safe to continue using the Range constantly or, a removal and run it a bit and replace?

Thanks!

@jdwood1111 I would recommend that you either use AFM like the factory intended or you disable it, I would not recommend switching back and forth.

For $50 there is a guy that will tune your ECM for it to permanently turned off much more affordable than the blackbear tune. I recommend this more than the Range product especially if you have to smog occasionally.

If I could go back in time.. I would tell myself to skip the Range AFM disabler entirely and go with an ECU AFM delete or tune and I might have saved my lifter and cam but here we are. I wouldn't recommend turning AFM back on after having it disabled for a period of time. This all happened to me around 170,000 miles.

Also.. part of the problem with getting the blackbear tune is you have to remove the AFM disabler so that you can log data for the Blackbear tuner and this is another moment in time when my motor had to reactivate the AFM lifters. You might be able to get around this by using OBD2 connector splitter. Sorry a bit off topic.