6 Liter Pinging

[mitchh30]

I have recently purchased a 2001 K2500 Suburban with 77k miles on it. I've noticed on cold start ups that it makes a pinging sound. Almost like a stuck lifter. But it goes away quickly. I asked the previous owner, and he said he had looked into it and was told it was just something these motors do. I called a mechanic I go to, and he said the same thing, but also told me it's a carbonization on pistons. He said that it could be "decarbonized" but it would only last about 3 months. Does this all sound accurate? Is there a chemical solution?

Thanks,
Mitch

[Jimmiee]

My 6.0 makes that noise. If you do a search you will see it common on 6.0s. If it were a carbon knock it would do it both hot and cold.

[Burden33]

My 2001 2500hd does the same thing and the only other time ki ever noticed the pinging if whenm you give it gas going up hills. the dealer told me it was normal for the 6.0L to make it

[Bikeman]

Found a TSB....

#01-06-01-028A: Info - Engine Knock on Cold Start - (Mar 18, 2003)

Subject:Engine Knock on Cold Start

Models:1999-2002 Chevrolet and GMC C/K Pickup and Utility Models
2002 Cadillac Escalade (2WD)
with 4.8L, 5.3L or 6.0L Engine (VINs V, T, Z, U -- RPOs LR4, LM7, L59, LQ4)

This bulletin is being revised to add an additional engine to the models section. Please discard Corporate Bulletin Number 01-06-01-028 (Section 06-Engine).
Some of the above vehicles may exhibit an engine knock noise that begins in the first 19,000-24,000 km (12,000-15,000 mi) of use. The knock noise is most often noticed during initial start-up and typically disappears within the first 5-30 seconds (may last longer in extreme cold temperatures). The noise is usually more noticeable on the initial start-up when the temperature is below 10°C (50°F) and may be more pronounced on the first cold start following a long trip.
This noise may be caused by an interaction between carbon that has formed on the piston, the piston motion and the cylinder wall. GM Powertrain Engineering, and an analysis of engines with this condition, has confirmed that the noise is not detrimental to the performance, reliability or durability of the engine. THIS NOISE DOES NOT HAVE ANY EFFECT ON THE LONGEVITY OF ANY OF THE ENGINE COMPONENTS.
Important: At this time, attempts to repair this condition by replacing the engine assembly or pistons are not recommended.
Please share the information found in this bulletin with customers who inquire about this condition. In the event they have additional questions or concerns, please advise your Area Service Manager.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

[Springthing]

Good find on the TSB. Thanks!

[mitchh30]

Thanks, just what I was looking for. I'm sure a few of you know what buyers remorse can feel like

[KAPPITAN420]

I have recently purchased a 2001 K2500 Suburban with 77k miles on it. I've noticed on cold start ups that it makes a pinging sound. Almost like a stuck lifter. But it goes away quickly. I asked the previous owner, and he said he had looked into it and was told it was just something these motors do. I called a mechanic I go to, and he said the same thing, but also told me it's a carbonization on pistons. He said that it could be "decarbonized" but it would only last about 3 months. Does this all sound accurate? Is there a chemical solution?

Thanks,
Mitch

things you can do to get rid of a ping.

high octang gas

colder plugs

and decarb the top of the motor.. gm has a special top engine cleaner they use.. it runs through your vacum..

best trick is after you run it let it sit as long as you can...so it soaks in to all the carbon build up.