2002 Chevrolet Trailblazer LTZ 4WD.
Engine size = V6 Check Engine codes Cam Sensor Errors P0016 P0014. Battery change the
night before. Changed the sensor- now reads no errors.
Question = -Starting a few months ago clicking noise with A/C running. Later, low metal scrape like
noise, similar to brake pads..yet not the pads.
-Not always super cool air, seen as good enough, charged fully.
-Died at start up, changed battery.
-Driving the next day, when A/C was turned on the car died while driving. A/C turned off car ran.
-Extreme load metal sound, similar to brake pads, but again pads fine.
-Took to shop, they changed cam sensor
-Ran so smooth, shifting great, running quiet.
- Pulled into a parking lot after idled for some time, and as I pulled in my power steering went out. I
could not turn the wheel at all.
- I slowed down, and my dashboard flashed the message, "low oil pressure." I glanced at the oil
pressure gauge and it subsequently dropped to zero.
- Then the car died.
- I tried to restart; it would start, power steering would be back then it would go out, then the
pressure would drop, then the car would die.
- I turned off the A/C and gave it a few minutes break.
- Then it was back in order, but I heard the infamous metal squeaking as I drove at low speeds and
it was not as loud as before.
- I was closer to home, so I drove home asap without the A/C and later back to shop. Again, A/C
-Shop has had it now for two weeks and says they need to call Chevy for advice. Is there any
advice you can give me? Is this a common mistake for my car? Thank you in advance for any help!
Thanks for the tip/donation.
I have been reading through your conditions. Could you please verify a few things for me. You
indicate a v-6. I believe you mean the straight 6 cylinder 4.2L. The eight digit of the VIN #
should be 'S'.
The grinding noise- does it only make noise with truck moving, and speed up with vehicle
speed, or will it also do at idle, and speeds up with engine speed. I believe the oil pressure
problem is just because the engine is stalling, and not an engine oil pressure problem. These
engines are very smooth and quiet, and hard to tell sometimes when it is in the process of
stalling, until it finally does, then you know it. Please verify these 2 things above, and i will have
some help for you, thanks. JK.
Chevy Trailblazer Codes P0014 And P0016
Thanks for the question; if I'm in anyway unclear, just let me know.
It's a straight six - habit of always having V...sorry about that. The metal noise used
to be heard as I pulled out of a parking lot with the windows down and went away as I
sped up. However, after the first shutting down drama, the noise intensified greatly
and only got louder as I sped up. This is the only time I could hear it with the windows
Lastly, after driving it back home after the first round at the shop, there was no noise
and after the second shut down it was muted at low speeds and went away after
approximately 20 mph, just as it did originally.
At idle there is no metal grinding noise, but for the last few months I've had a
knocking noise at idle when the a/c was on, and ceased when we turned the a/c off.
Lately, I really didn't notice it and thought it went away...I know terrible idea... I'm
starting to think I have an air compressor problem. If you think so as well, do you
think it's a compressor part or in need of complete replacement?
Thanks for the info. No problem with the 'V' thing, happens allot. Sounds like you have more
than 1 problem here, some may be related. For the dies out at low speed, a common fix is to
have the throttle body bore and blade cleaned with a carbon cleaner. With the mileage you
have, may have some carbon there that will cause a low speed stall if a/c on, or high steering
load such as parking lot maneuvers. Now the noise in the a/c does sound like the compressor
is locking up internally, which would give that load noise. We have also had problems with
water pump worn out. To check for water pump worn out, just grab fan with engine off and see
if it wobbles; but a loose water pump will normally be noise all the time. Other source of noise
while driving is a front axle seal or axle bearing on the front differential. Have a tech check for
looseness in the axle.
There is a bulletin about poor a/c performance at low speeds caused by a faulty radiator fan
clutch. That may explain your problem with 'a/c not always supper cool, but good enough.
If a compressor is locking up, that would explain the loss of power steering, but also refer to my
first mail about engine starting to stall.
As you can see, some of these things may be related, some not. Have that throttle body
cleaned which should take care of the low speed stall, then have tech look into the noises in
the areas i have described.
I know this sounds like a lot to swallow, but these are the common areas for the complaints
described. Good luck with repairs.
I will send a couple of pics that may be useful. Thanks again for tip/donation, JK.