new Burb owner!

[Macumazahn]

Hi, new to these forums, thinking about subscribing so I can post in the Suburban subforums.

Just bought a Suburban 2500, is an x-Border Patrol vehicle, was serviced regularly at the same dealer in Arizona, but I'm sure it was worked pretty hard. I have been wanting a large 4x4 that I can play with and learn on, but also take the family out for a ride if necessary.

2006 Suburban 2500 4x4, 96K miles, 2000 engine hours, 6 liter engine, BF Goodrich Mud-turrain tires. It has no carpet but has a heavy rubber matting over all the interior, which is great for muddy boots or kids spilling drinks.
It drives really well and has good power, accelerates and shifts smooth, but does have some minor dents here and there, and a damaged spare tire holder from someone backing over something looks like. Have had it a month, drove it 200 miles the other day to Charlotte and it ran like a champ. Alittle noisy, but I think that is the tires.

I had my expensive mechanic look over it, and he found no leaks after he drove it for 30 minutes.

Question is:
1. When I first picked it up from the delivery truck, it had a clicking sound in the engine. photobucket video for sound Sounds like a lifter or valve maybe? Anyway, I have a decent 1 year power train warranty on it and want to get it fixed. However, I changed the oil, and the sound went away for a week, drove it on a 200 mile trip, no problem, no sound, then I let it sit for a week, and the sound comes right back. It seems to come back when I don't drive it for several days, if I drive it daily, it stays away. I'm guessing I'll let it sit, and try to catch the mechanic when it repeats the sound so he can isolate.

Is this the right thing to do? Should I be really worried about it, could I be causing more damage by driving it? (forgive the noob question, very new to working on engines here)

Thanks, and am enjoying reading the forums already.

 

[munepit]

I think I know where the little dents and dings came from. Illegals heads!!!!!




Welcome to CK5! That should be a great rig for you.

 

[jeff in co]

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In the early production run of the LS-series engine, some engines encountered abnormal amounts of 'piston slap' - a problem caused by too much clearance between the cylinder bore and the piston. 'Piston Slap' sometimes sounds more like a knock or the sound of a diesel engine running, it is also typically worse when the engine is cold and lessens as the engine reaches operating temperature. The noise of 'Piston Slap' often is louder when listening for it below the oil pan.

 

[rebelgregory]

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In the early production run of the LS-series engine, some engines encountered abnormal amounts of 'piston slap'

What he said. I had an 01 1500HD with the 6.0. Piston slap is a fact of life. Everything I read said it was not detrimental to the engine and didn't shorten engine life. That's why there was never a recall. I can also tell you that chevrolet will do nothing about it.

Long story short, I just had to get used to it. Never had any problems , but remember it well because I'm finicky about stuff like that and it was unfixable.

 

[Macumazahn]

What he said. I had an 01 1500HD with the 6.0. Piston slap is a fact of life. Everything I read said it was not detrimental to the engine and didn't shorten engine life. That's why there was never a recall. I can also tell you that chevrolet will do nothing about it.

Long story short, I just had to get used to it. Never had any problems , but remember it well because I'm finicky about stuff like that and it was unfixable.

Great info guys, thanks much. I had never heard of piston slap before, but I just spent 30 minutes reading about it. Seems pretty common with Burbs, but as you said, causes no problems. It is less common with newer vehicles though. I think I might just watch it for a bit, I might also try a quality synthetic oil at next change.

I'm still wondering if it is a lifter, as from what I read, a lifter noise increases as RPMs increase? I wonder why piston slapping wouldn't increase also, but from most places I read that if it is piston slap it should go away as the RPMs go up. Does this seem correct?

 

[4xcrazy]

Sounded like a single lifter/rocker arm tick to me, I was fighting a few lifters on the new motor in the Burb a few years ago, sounded just like that.

 

[rebelgregory]

Correct. The piston slap is caused by the unequal thermal expansion rates of the dissimilar metals of the piston and cylinder. As RPM goes up, the oil film in the oil ring of the piston gets a little more pressure and the piston has a little less time to rock or 'slap' in the cylinder. Mine usually went away at about 1500-ish RPM.

By all means check your lifters, but it's probably the slap. And I would advise against synthetic oil if you're just doing it to get rid of the slap. If it works, it's only temporary. At least that was my experience.