Want to take my 2010 Yukon XL Denali with 180,000 miles for a family trip from Michigan To Florida - Can you help me make this a success!

[bobby2175]

That is great to hear! Please so send in a follow-up log with the tune loaded for our review and the tuner can see what he can do about the idle.

Will do. I want to see if cleaning up the injectors will solve it before I have you adjust the tune. Thanks so much!

 

[bobby2175]

I could be completely wrong, but you might be better off using an actual injection cleaner to do that job, as opposed to using E85. That’s not to say E85 won’t do the job, I’ve just never used it since I have the 6.2.

I’ve always had good luck with Lucas and the ACDelco top end cleaner as well as their injector cleaner (make sure you use the one designed for Flex-Fuel). I’m pretty sure there’s a TSB out regarding this. I’ll have to check my TSB binder. It’s currently in the house and I’m out in the shop at the moment.

I started using Berrymans B12 for a few tanks with 93 while I worked up the courage to use some E85 with the original OEM O2 sensors. A few of the guys here mentioned that it was a good way to clean the injectors.

 

[bobby2175]

I'm curious about everyone's view of engine ticking when cold start on a cold day. Today, it was low 20s with a pretty good wind, so it was cold out. I decided to do a remote start because one of the kids asked about it and about 2 minutes later, I'm locking up the door and I hear the ticking from the truck (I'm locking the door inside the garage and the truck is parked outside and out of sight around the bend of the circle drive). I walk over to the truck and sure enough it's ticking - much louder at the wheel wells.

I get to my first stop about 30 minutes of driving and the tick is completely gone.

Would love to get your thoughts on if this is something to think about or address. I vaguely remember this happening 150K miles ago, but haven't noticed it since.

I read some various threads on various boards about similar issues.

I've been using Mobil 1 for years...this time around, I decided to use a AC Delco oil filter.

Your thoughts?

 

[Geotrash]

I'm curious about everyone's view of engine ticking when cold start on a cold day. Today, it was low 20s with a pretty good wind, so it was cold out. I decided to do a remote start because one of the kids asked about it and about 2 minutes later, I'm locking up the door and I hear the ticking from the truck (I'm locking the door inside the garage and the truck is parked outside and out of sight around the bend of the circle drive). I walk over to the truck and sure enough it's ticking - much louder at the wheel wells.

I get to my first stop about 30 minutes of driving and the tick is completely gone.

Would love to get your thoughts on if this is something to think about or address. I vaguely remember this happening 150K miles ago, but haven't noticed it since.

I read some various threads on various boards about similar issues.

I've been using Mobil 1 for years...this time around, I decided to use a AC Delco oil filter.

Your thoughts?

I had a ticking on my 2012 at cold startup for a few months and thought it was one of the rocker trunnions I'd installed when I did my DoD delete back in 2021 because it sounded metallic. I have 20K on that setup now, so I was dreading the prospect of tearing into it again. So while we were camping last week, I popped the hood for a good look around. Lo and behold, the rearmost exhaust manifold bolt was backing out on the driver's side (I'd installed ARP manifold bolts, which are the best, and torqued them to spec), and I'd developed an exhaust leak on #7 that was the source of the cold tick. Re-torqued the bolt and the tick is gone.

Moral of the story: check to make sure all of your exhaust manifold bolts are still there. It's common for the OEM bolts to break off after several years, and when you have an exhaust leak, you'd swear it was in the valve train because the sound is almost indistinguishable.

 

[bobby2175]

I had a ticking on my 2012 at cold startup for a few months and thought it was one of the rocker trunnions I'd installed when I did my DoD delete back in 2021 because it sounded metallic. I have 20K on that setup now, so I was dreading the prospect of tearing into it again. So while we were camping last week, I popped the hood for a good look around. Lo and behold, the rearmost exhaust manifold bolt was backing out on the driver's side (I'd installed ARP manifold bolts, which are the best, and torqued them to spec), and I'd developed an exhaust leak on #7 that was the source of the cold tick. Re-torqued the bolt and the tick is gone.

Moral of the story: check to make sure all of your exhaust manifold bolts are still there. It's common for the OEM bolts to break off after several years, and when you have an exhaust leak, you'd swear it was in the valve train because the sound is almost indistinguishable.

Thank you! I will take a look and see if I see anything.

Should I be replacing all of the bolts, just torque checking all of them or if they are still holding assume it's fine?

Does torque spec of 15 ft-lbs sound right? I happened to see a video for the older model Yukon that stated that.

 

[Geotrash]

Thank you! I will take a look and see if I see anything.

Should I be replacing all of the bolts, just torque checking all of them or if they are still holding assume it's fine?

Does torque spec of 15 ft-lbs sound right? I happened to see a video for the older model Yukon that stated that.

If you find any missing, come back here and we can advise you from there. Replacing them all isn't recommended unless you are willing and ready to pull the heads because there's a high probability that you will break one or more of them off during the removal process. If that happens, your day is ruined and you'll either need a welder to weld a nib on the broken ones to get them out, or take the heads off and have them removed by a machine shop. You could drill them on the bench of course, but the head material is aluminum so one slip of the drill and you have a whole new set of problems.

If you're missing any of the bolts on either end of the manifolds (the most likely ones to break), several vendors including Dorman make repair kits that have a little clamp that bolts an unused hole on either end of the head and uses a set screw to apply pressure to the manifold to keep it pressed against the head. But they're a pain to get on when the broken ones are at the rear.

I'm missing the rearmost bolt on the pax side of my 2007 but it's not leaking yet. When it starts leaking, I will remove and replace all of the bolts, because I will have reserved the time to pull the heads if I need to. I might get lucky, but I want to be ready if I'm not.

And yes the torque spec is 15 ft lbs, but it's done in two stages. 11 ft lbs first, and then 15 for the final.

 

[Geotrash]

While I'm thinking of it, I *was* successful in removing all of the exhaust manifold bolts without breaking them on my 2012 when I did the cam swap. But the engine only had maybe 110K on it and was a dry country truck when I bought it, so there was no corrosion anywhere. I used Deep Creep penetrating oil over a couple of days before I did the job and they came out easily. But I wouldn't recommend this if you're not prepared to pull the heads because sure as the moon, you'll break one if you're not.

 

[donjetman]

@bobby2175 if its that loud sounds like lifter problem to me.

3 of exhaust manilold bolts (corners) were gone at 130k miles when we bought the truck 5 yrs ago. Not noticeable at idle. Installed 3 bridge clamps. Still going strong at 192k.

 

[bobby2175]

@bobby2175 if its that loud sounds like lifter problem to me.

3 of exhaust manilold bolts (corners) were gone at 130k miles when we bought the truck 5 yrs ago. Not noticeable at idle. Installed 3 bridge clamps. Still going strong at 192k.

I don't know anything when it comes to lifters - I'm assuming that would require a shop to work on?

 

[Geotrash]

I don't know anything when it comes to lifters - I'm assuming that would require a shop to work on?

Post a video, and we can help assess.