Piston Slap Question

[Jcol]

When I purchased my 02 2500 HD in March of 09 I didn't know about the piston slap noise with the 6L engines till I started visiting this forum. At the time of purchase my truck have about 70K miles on it and there were no ticks or other unusual sounds from the motor at startup. My truck now has 95K on it. Last week my wife and I were on vacation with our 5th wheel trailer and she started the truck up first thing in the morning to go out. I was sitting outside and I heard a strange rattle coming from the engine, it cleared up within 30 seconds. The next couple of mornings I started the truck with windows down and heard the same sound each time. It sounds like someone has a bag of glass marbles and is under the hood shaking them. It clears up pretty quickly and doesn't seem to happen after the first cold start of the day. It also cannot be heard from inside the cab with the windows up. The engine runs perfectly and pulls my 30 foot 5th with no problems. I run 5W/40 synthetic and change at 5K intervals. Just would like to confirm that this is the piston slap noise and not something else that I should be looking into further. Thanks.

[old dog]

 

 

When I purchased my 02 2500 HD in March of 09 I didn't know about the piston slap noise with the 6L engines till I started visiting this forum. At the time of purchase my truck have about 70K miles on it and there were no ticks or other unusual sounds from the motor at startup. My truck now has 95K on it. Last week my wife and I were on vacation with our 5th wheel trailer and she started the truck up first thing in the morning to go out. I was sitting outside and I heard a strange rattle coming from the engine, it cleared up within 30 seconds. The next couple of mornings I started the truck with windows down and heard the same sound each time. It sounds like someone has a bag of glass marbles and is under the hood shaking them. It clears up pretty quickly and doesn't seem to happen after the first cold start of the day. It also cannot be heard from inside the cab with the windows up. The engine runs perfectly and pulls my 30 foot 5th with no problems. I run 5W/40 synthetic and change at 5K intervals. Just would like to confirm that this is the piston slap noise and not something else that I should be looking into further. Thanks.

thats common ,the pistons are short on the skirt to cut friction because the new engings run a lot hotter than the older ones and the expand a little bit with heatthen they quieten down .i know its sucks but they havent come up with a good answer yet.

[04JJHD]

I have heard the reason is GM mass manufactures the pistons instead of sizing them for each engine. I had this problem, not to bad but it was embaresing. I used to use castrol 5W30 with lucas oil stabilizer and had the ticking only in winter. I switched to amsoil 5W30 with no lucas and problem solved. also the owners manual recomends 5W30 or 10W30 not 5W40

[Jcol]

I have heard the reason is GM mass manufactures the pistons instead of sizing them for each engine. I had this problem, not to bad but it was embaresing. I used to use castrol 5W30 with lucas oil stabilizer and had the ticking only in winter. I switched to amsoil 5W30 with no lucas and problem solved. also the owners manual recomends 5W30 or 10W30 not 5W40

 

Thanks for the replies. I made a mistake on my original post. I'm running Pennzoil Platium 5W/30 which I believe is one of the recommended oil weights for the truck. The sound is interesting in that immediately after the truck starts and settles down to idle speed there is no sound for 2 or 3 seconds, it then comes on and lasts for about 20 to 30 seconds and then just fades away. Next oil change I'll try a different brand of sythetic oil. I used to use Shell Rotella with my old GM 6.5 diesel but it becoming harder and harder to find.

[[email protected]]

I run 10w-30 in mine, all I have is a little lifter ticking on mine. It comes and goes as it pleases, whether hot or cold.

[[email protected]]

It depends on the noise, there was a valve tap that all the 5.3's and 6.0's were notorious for. It's actually carbon build up so a good fuel injection kit such as an E-Tech cleaning kit would do the trick. If it’s a bottom end noise that's a whole other subject. I actually just took the motor out of my 02' 2500HD to rebuild it before the winter, two of the pistons in cyls. 2+5 were worn down. The skirts were too short to break but were just worn.

[arwriter]

Has anyone heard of the piston slap issue in the 1999 model year 6.0 engines? I just bought one with 75k original miles on it and I have yet to hear what others describe as the piston slap noise.

[markw8]

The 99s probably use the same parts. That being said, I've never heard or read of an engine failure because of it. Modern engines use lighter weight pistons that are shorter and tend to rock untill they warm and expand. If the noise lasts longer than a minute or two, it's not piston slap. Look at a decarbon or other noise.

 

If you use premium fuel this speeds carbon build up. Corvettes have had this too. None have had problems because of it.

 

Mark

[Prokopchuk_9]

if you get it, it aint gonna hurt anything. my last truck with LQ4 6 litre did it, did it for 200k kms....this one that i have now doesnt do it. fingers crossed.

 

flip of a coin