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.

 

[rich5368]

Just drive. My 04 just hit 196k miles. piston slap every day. Runs like a champ

 

[chacho44]

My 00 5.3 w/150k does it on the cold start then goes away. It gets annoying sometimes cause ppl think my motor is shot. But I guess it normal and dont affect it. I been considering a turbo kit for mine but wondr if I will hurt something any thoughts fellas.

 

[Cobra]

I got it! Mobil 1 every 3to 4k. Always been there, It use to not be that bad but seems to have gotten a lil louder lately. Tahoe runs smooth and strong without issue.

 

[DaRosa218]

Has Anyone tried Lucas Oil Stabilizer? I am going to change my oil this weekend and replace a quart of oil with it. I will post results

 

[Thumper8302]

ive ran lucas in mine..... 2001 with 235xxx on the clock..... lucas has helped but its still there some.... still runnin strong and smooth

 

[LaOrange]

Hi All
I would try to make sure what is going on Before you change things
Most likely piston slap.
BUT could be many other things.

#1 pull an oil sample send it off to someone like Blackstone Labs

This is very inexpensive to do and will tell if you have any
severe problems Rod or Main bearings Coolant in oil ect.

" If you pre pay for six in advance even less costly '

Sinse i have started doing so I have only been changing my oil twice
a year No mater what the milage

I use only high qualty synthetic oil and good filters Even at that it shows
I am wasting Time a Money changing that often

I Drain my Transmission Pan By the Plug with each oil change also
I use Full synthetic trans fluid "You will only get about 3+ quarts out"

The last analysis showed almost NO WEAR with 149++K miles

I Do a LOT of TOWING Open Car Trailer with a Corvette
I have towed this set up on several long trips through mountain ranges
wit no problems

I have added a LARGE trans cooler 28K lbs. Stacked Plate Type and kept
the factory cooler

These trucks will last a Very Long time with Good mainantance and mods to
help with the week areas

Good Luck
But rember you should try to know were you are going befor you leave
you can plan better