Buick 3.8 V6 ...carbon rap ?

hello all,

99 Camaro, with the Gen II motor, 84K miles, driven daily & religiously
maintained... this just started happening to me -- when started up,
very loud tapping noise, ala stuck lifter or valve

after 15 minutes of running, the noise gradually diminishes, then is
gone

all throughout, factory oil pressure gauge reads its usual psi, car
runs like it always has

after some research, I found this : the 93-01 Cadillac Northstar and
96-02 Buick 3.8 V6 engines have a tendency to carbon-up if babied. If
it gets carboned-up, you will hear "cold carbon rap" when you start it.
Sounds alot like a collapsed lifter. That is the piston contacting
the carbon in the cylinder head causing piston slap. No need to worry.
One or two wide-open-throttle runs will clean out the combustion
chambers.

by me the weather so far hasn't been conducive to doing some WOT, but I
did rev up the motor while in Park a couple of times, and wouldn't you
know, the tapping noise hasn't been as loud, nor has it lasted as long,
as it was doing originally.

is "carbon rap" bogus, or more than a coincidence in my case ?

any comments appreciated :-)

wrote:
> hello all,
>
> 99 Camaro, with the Gen II motor, 84K miles, driven daily & religiously
> maintained... this just started happening to me -- when started up,
> very loud tapping noise, ala stuck lifter or valve
>
> after 15 minutes of running, the noise gradually diminishes, then is
> gone
>
> all throughout, factory oil pressure gauge reads its usual psi, car
> runs like it always has
>
> after some research, I found this : the 93-01 Cadillac Northstar and
> 96-02 Buick 3.8 V6 engines have a tendency to carbon-up if babied.

Don't understand what you are saying here. Are you saying that by not
keeping up with maintenance the car will carbon up? Or are you saying
that by not driving at half or greater throttle the engine will carbon
up.


> If
> it gets carboned-up, you will hear "cold carbon rap" when you start it.
> Sounds alot like a collapsed lifter. That is the piston contacting
> the carbon in the cylinder head causing piston slap. No need to worry.
> One or two wide-open-throttle runs will clean out the combustion
> chambers.

Where did you find this...not on the GM website I'm going to guess. I
will vote for a collapsed lifter.



>
> by me the weather so far hasn't been conducive to doing some WOT, but I
> did rev up the motor while in Park a couple of times, and wouldn't you
> know, the tapping noise hasn't been as loud, nor has it lasted as long,
> as it was doing originally.
>
> is "carbon rap" bogus, or more than a coincidence in my case ?



>
> any comments appreciated :-)

Comments inserted.