Help - Knocking noise on 2003 Tahoe

[Anna]

over 120K miles. Suddenly started making this horrible knocking, tapping noise when start up from cold and usually goes away when driving it. But then, I let it idle in park noise started again. I have no clue when comes to cars and I don't want to get ripped off. i've listened to several videos of "noises" and could be something called piston slap or crank and rod issue (the latter is the bad one apparently).

I have taken good care of my car. Regular services, oil change every 3K. Love my car.

My Q - if it's piston slap is it possible for this to suddenly start up? What's the remedy (if any)?

if it's the latter - well...............!

 

[blueflamed03]

piston slap, if you have decent oil pressure inside, it's normal. My 03 has 91,000 miles and talks to me even when warm

 

[Anna]

Tracy - thank you. Is there anything I can do about it?

 

[pats hoe]

My 01 has piston slap in mornings then goes away 125,000 miles,now that its gettiung colder its there evrytime i start it up then goes away when warm.Doesnt bother me at all.

 

[blueflamed03]

Tracy - thank you. Is there anything I can do about it?

sadly, no...pretty common though, annoying, but nothing mechanically wrong or hurts driveability.

 

[boostedgsxr1k]

GM had a solvent called " top end cleaner" I did that on mine awhile ago. Greatly improved the noise. Still there slightly, but goes away now after 45 sec of driving. The stuff is hard to come by but does wonders if it is really loud.

 

[puckhead]

Happens on mine too, I just done drive it hard the first few minutes. Should be good to go otherwise! Like Tracy said

 

[bkboatnsleds]

Put in the 6.0l It fixed my piston slap

 

[dwmmatt23]

normal on most all our tahoes, glad it goes away though after a few seconds of warming up

 

[Redhoe01]

I started a thread about ATF in my oil and after seeing this thread, realized my piston slap is gone. Its 30 degrees here in NH and my Tahoe last year while living in Texas piston slapped in warmer weather then this. Maybe it fixed that too.