It start 2K miles ago, truck justed turned 42K. Most mornings now it'll knock for 5-15 seconds, it ticks me off. I know GM says it won't hurt any thing but it sure does sound bad. I've used Mobil 1 since my first oil change and thought I may miss this problem. I've read that the GM top end cleaner helps, true? Suggestions?
Jim

 

welcome to the club

 

Why don't you do a search on this forum. There is lots more info,

 

I wish I had just cold engine knock!! Mine has the piston slap at all times... even worse after its been running for at least 20 minutes. I had it since day 1, and I will just keep on living with my piston slapping 4.8 <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> .
-Kurt

 

I ran a can of Seafoam engine cleaner through mine the other day, it lessened the col-start knock.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 01 Silverado:
<strong>I wish I had just cold engine knock!! Mine has the piston slap at all times... even worse after its been running for at least 20 minutes. I had it since day 1, and I will just keep on living with my piston slapping 4.8 <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> .
-Kurt</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">See, it's not all that bad. You could have what this poor guy has (01 Silverado). Mine only ticks for a little bit while it's cold. Nothing big I'm sure it won't affect anything.

Remember, there are tons of people out there with some type of engine noise and most have not had any detrimental affects to their engines, even after 100,000 miles. My $.02

 

Well, I made it to 47k on the first one with no knock. The new one has 16k on it and still sounds strong.

Greg

 

I'm not holding my breath but I just had my fuel system cleaned at 26k and it seems to have gone away over the past 2 weeks. I'm going to change the oil to get the crud out and will see if it's still there.
Lar