# GM 6.0L gas engine and piston slap



## joed (Dec 26, 2001)

I am looking at acquiring a 2001 Chevy 2500 HD 4X4. The truck has 63 000 km (about 40 000 miles) and the asking price is $31 000 Canadian (about $20 000 U.S.) The body is in excellent shape and it was never used for heavy work or plowing. What concerns me about the truck is the engine. When I took it out for a test drive, I noticed two things:
1. On start up, there was tick, tick sound for 15 seconds or so.
2. The truck was very sluggish on the road, seemed to be hunting for gears and was struggling to get up small hills.

Is this normal for this engine or does this engine have that dreaded piston slap condition that a lot of the GM trucks from 99-02 have?

Can anyone help me out with this?


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## John DiMartino (Jan 22, 2000)

The 6.0 is noted for piston slap,if it bothers you dont buy the truck,because Gm will not fix it for you.The 6.0's that work real hard also consume a little oil,a little more than most people like,so keep that in mind.As for the truck being sluggish,all small blocks are not going to be real strong in low end power.The 8100 feels twice as strong as the 6000 under 2300RPM,form the ones ive driven,once up in the mid range the 6000 is fine and plenty strong.Do not expect it to pull hills in OD,you need a diesel or big block to do that.The truck may have been traded in because of the knock,see if you can dig up any info,run the VIN#,try to find the original owner,maybe you could ask him why he sold it.


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## wxmn6 (May 23, 2001)

From what I have heard in the other forum, I think that sometime the 2500HD & 3500 owners hears tick sounds for a few seconds at the startup but then dimished. But that was from most of diesel engine owners, but I think that some gas engine owners notice the same thing, I THINK. I am the owner of '02 2500HD with 6.0L Vortec gas engine, but because I am deaf, I cannot hear a small sound like tick or piston slap. But as you noted that the truck is at 40,000 miles mark, the transmission should have preventive maintenance done. I don't remember exactly what part of transmission that could go bad, but I have heard that several owners had problems with transmission at around 50,000 miles mark and it costed them alot more than just doing preventive maintenance. So if you buy that truck, be sure to have the transmission serviced. I believe that it is a simple maintenace and cost only a little. Good luck!


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## staley52 (Dec 17, 2001)

I have been told that the piston slap is a big enough complaint that gm is warrenting the motor till 100,000 miles to show it is not a serious problem


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## SnowMatt13 (Jan 8, 2003)

That tick noise is normal. Was told that by the dlr. I work at, and Chevy. The do in most cases give you an ext warranty. Call their cust serv center 800.222.1020 8am-11pm EST. Also my service manager gave me two information sheets concerning this from GM. They're not bullitens, but if you go to your GM dlr. they should be able to look up the # and give you a copy. Both suggest...."This noise does not have any effect on the longevity of any of the engine components" also...."At this time, attempts to repair this condition by replacing the engine assembly or pistons is not recommended" What gets me is that it says ...at this time... meaning to me that they know it's there, but not sure what the actual effects are yet.

Anyway the here's the numbers:
Document 1. Document ID#833250
Info-Engine knock on cold start #01-06-01-028
Dated 11/27/2001
Vehicles involved: 99-02 Chevy+GMC C/K P.U. 
and utility models, 02 Cad Escalade (2WD)
with 4.8L, 5.3L 6.0L gas engines 
VINs V, T, U

Document 2. Document ID# 816465
Info-Engine Knock on cold start #01-06-01-022
Dated 8/22/2001
Vehicles involved: 2001-2002 Chev+GMC C/K PU
and Utility models
with engine 6.0L VIN U


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## ddm (Sep 5, 2001)

I have an '02 2500 HD; exact same tick noise at startup. Almost sounds like it's running without oil, seems worse in the cold weather. No problems at all with anything yet, 38K on it now. Usually quiets back down in just a few seconds after startup. 

I also get a noise when towing heavy loads and working the engine (uphill, accelerating at start, etc.) that sounds MUCH worse. Almost sounds like a diesel, I don't know if it's lifters/valves noise, maybe this piston slap just magnified??
Dealer just told me they do that. It is better if I run higher octane fuel, 89 or 92. If I use the basic 87 it is terrible. It doesn't seem to be any loss of power, just kind of like fingernails on the chalkboard; your sort of programmed to know that it just doesn't sound right.

I guess I'm a little of your subject there, just to let you know a little more info if you do get the truck and run into this after its your baby. Good luck


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## Terrasnow (Oct 23, 2002)

Any word on whether or not GM fixed the piston slap problem in '03 or '04?

(What a shame.)


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## Earthscapes (Feb 2, 2001)

haven't heard any ticking noise in my 03'


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## EZSnow (Aug 13, 2003)

I owned a 6.0 and loved it. 

Mine was a 99 2500 ex cab. I noticed the 'tick' at idle when cold. bring rpms over 1,000 and it would go away. I wrote it off as a sticky lifter, but the more I heard about the slap, I figured that was the deal. 

As for the uphill, accelerating, loaded noise... that's plain 'ol preignition... BAD!! I had to run 89 in mine if I was towing anything. I think it let the computer run more timing, too, cause it felt like it made more power. 

From what I understand about the situation, the original tolerances were too tight and they loosened the specs for longevity. The pistons are a shallow skirt design.
Shallow skirt + loose tolerances = piston slap!

I put 104,000 miles and two plow seasons on it over 4 years, it was a great truck, but it just can't compare to an oil burner!


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## PROCUTSLAWNCARE (Oct 18, 2003)

Just bought an 04 GMC with the 6.0l 400 motor, no noise yet, its only got 600 miles on it, but gmc or chevy listed nothing or told me nothing about a 100,000 mile warranty because of this tick, just the standard 36000 mile coverage. As stated above, what a shame.


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