'07 Yukon XL Denali motor tick when 1st startup

[BSarteSr]

I have had my '07 Yukon XL Denali since 2008, bought it from dealer with 12k miles, they said it was a lease that was turned in.

Pretty much from the very beginning there was a very small ticking sound when it was first started. I am very aware of all the noises my cars make (done many frame off restorations, rebuilt MANY SBC/BBC/Buick motors) and this tick always sounding like a lifter, but not serious since it went away after a minute or so when the engine warmed up.

Recently (in the past month or so) it has gotten more pronounced when I first start it up and lasts a little longer, usually until it is warmed up, then seems to run fine.

I have changed the oil every 5k miles, filter every other oil change, use good brand of synthetic oil, use 5/30 in winter and 10/30 in summer.

Last time I changed the oil I added some STP oil treatment (I am old school and that has always been good for the lifters, especially in my BBC's). Seemed to do some good, ticking was not as pronounced nor lasted as long until yesterday. Weather has gotten a bit more chilly, but my truck is ALWAYS been kept in a climate controlled garage.

My question is about replacing the lifters in these LS motors? From the engine work I have done, very aware of the ins/outs of just replacing lifters versus a new cam/lifters/head work and what it would probably take to do all of that since I have done any work on these newer LS motors.

Are there any other additives that I can try (about to change the oil in the next week or so)?

BTW, the engine has 158k miles on it and like I said, oil changed every 5k miles!

 

[wjburken]

I have had my '07 Yukon XL Denali since 2008, bought it from dealer with 12k miles, they said it was a lease that was turned in.

Pretty much from the very beginning there was a very small ticking sound when it was first started. I am very aware of all the noises my cars make (done many frame off restorations, rebuilt MANY SBC/BBC/Buick motors) and this tick always sounding like a lifter, but not serious since it went away after a minute or so when the engine warmed up.

Recently (in the past month or so) it has gotten more pronounced when I first start it up and lasts a little longer, usually until it is warmed up, then seems to run fine.

I have changed the oil every 5k miles, filter every other oil change, use good brand of synthetic oil, use 5/30 in winter and 10/30 in summer.

Last time I changed the oil I added some STP oil treatment (I am old school and that has always been good for the lifters, especially in my BBC's). Seemed to do some good, ticking was not as pronounced nor lasted as long until yesterday. Weather has gotten a bit more chilly, but my truck is ALWAYS been kept in a climate controlled garage.

My question is about replacing the lifters in these LS motors? From the engine work I have done, very aware of the ins/outs of just replacing lifters versus a new cam/lifters/head work and what it would probably take to do all of that since I have done any work on these newer LS motors.

Are there any other additives that I can try (about to change the oil in the next week or so)?

BTW, the engine has 158k miles on it and like I said, oil changed every 5k miles!

The two main ways that your lifters will fail in your 6.2 is the lifter rotates in the plastic lifter tray and the roller starts to slide on the lobe of the cam. No additive will help with this. The otherness is the roller itself locks up and scrubs the cam. I am doubtful that an additive would help here either. I’ve been there and ended up replacing a motor because a roller grenaded in my 2007 at 150K and then a roller locked up in the replacement after 120K.

It’s not super difficult to replace the lifters but you may find you need to replace the cam if there is any damage, as I’m sure you know. To get to the lifters you will need to remove the heads as they are not accessible from the valley on your generation of motor.

 

[Geotrash]

In addition to Wade's comments, I'll just add that replacing the lifters requires pulling the heads on LS engines. At that point, you might as well do the cam, valve springs and rockers as well.

 

[BSarteSr]

Thanks for the input!

That is what I needed to know, know wheres near as easy as doing an older engine.

Engine seems to run fine once it has warmed up, probably best just to start finding someone who can do a job like this, getting to old to do it myself!

Might be easier to find a very low mileage motor for replacement?

 

[Geotrash]

Thanks for the input!

That is what I needed to know, know wheres near as easy as doing an older engine.

Engine seems to run fine once it has warmed up, probably best just to start finding someone who can do a job like this, getting to old to do it myself!

Might be easier to find a very low mileage motor for replacement?

Finding a lower mileage L92 will likely be difficult, as they are popular for engine swaps (read: expensive), and they were replaced by the L94 in 2010. If you bought one of those, you would have to deal with the AFM stuff and that would mean a new cam, etc etc.

The bottom end on these engines is built hell-for-stout, and will hold up. If It were my money - especially if I'd owned the truck virtually since new, I would make the upgrades before I'd put a different engine in it. With that work, you would effectively be addressing the most significant concerns in that engine's reliability and long-term durability (valve springs, lifters), and if you put in a new cam, you'll get petter performance and mileage to boot. I'm doing the job on my 2012 Denali now for all of the same reasons, except that AFM is the primary weakness on that particular engine family.

 

[BSarteSr]

Finding a lower mileage L92 will likely be difficult, as they are popular for engine swaps (read: expensive), and they were replaced by the L94 in 2010. If you bought one of those, you would have to deal with the AFM stuff and that would mean a new cam, etc etc.

The bottom end on these engines is built hell-for-stout, and will hold up. If It were my money - especially if I'd owned the truck virtually since new, I would make the upgrades before I'd put a different engine in it. With that work, you would effectively be addressing the most significant concerns in that engine's reliability and long-term durability (valve springs, lifters), and if you put in a new cam, you'll get petter performance and mileage to boot. I'm doing the job on my 2012 Denali now for all of the same reasons, except that AFM is the primary weakness on that particular engine family.

Thanks! What is the AFM?

 

[kbuskill]

Thanks! What is the AFM?

Active Fuel Management, also known as DOD/Displacement On Demand. It turns 4 cylinders off under certain conditions to "save fuel". It works by collapsing the lifter to keep the valves from opening on those cylinders.

I have heard/read that the 6.2L suffer from piston slap on start up. I don't own a 6.2L so I can't say what it sounds like compared to a lifter tick.

Just out of curiosity, are you using oil filters with a good anti drain back valve?

Does it make the noise every time you start it or mainly after sitting overnight?

 

[donjetman]

AFM = Active Fuel Management, it de-activates cylinders for improved gas mileage at low power settings by taking away oil pressure to certain lifters so those valves don't open. PROBLEMATIC !!!

 

[mikeyss]

I have an 09 6.2 that had the noise you describe and thought it was a lifter. I found out too late that the valve seal can fall out of the head. I pulled the heads and found the lifters were fine, it was the valve seal making the tick noise until it warmed up, it would sort of seat itself as it warmed up. But the last time I started it, the valve seal fell out and destroyed a piston. It was running perfectly before it happened, and the next time I started it...ka boom!

 

[PG01]

I have an 09 6.2 that had the noise you describe and thought it was a lifter. I found out too late that the valve seal can fall out of the head. I pulled the heads and found the lifters were fine, it was the valve seal making the tick noise until it warmed up, it would sort of seat itself as it warmed up. But the last time I started it, the valve seal fell out and destroyed a piston. It was running perfectly before it happened, and the next time I started it...ka boom!

Btw, How’s that coming along mikey