My 2003 chevy trailblazer makes a noise like pressure is releaseing as soon as turn the car off, What is this?

Does the vehicle make any noises while driving? If there is a "growling or roaring " noise associated with the vibration, check the right front hub bearing. If there are no noises and only vibration, check the right front upper ball joint and control arm bushings. The Trailblazer's upper ball joint and control arm bushings become worn and cause the tire and wheel assembly to shimmy while driving. The vibration stops when turning left because of weight transfer to the right side which keeps the wheel steady for a moment. Also, check the tire for irregular wear.

If the service engine soon light is flashing, it means the computer has detected an engine misfire with the potential of catalytic convertor failure. Don't just tune it up. Bring it somewhere they can read the trouble code. Sometimes it will designate which cylinder is having the problem.

I only suggest using factory tune up parts. Don't forget to set you tire pressure according to the driver's door sticker.

It could be a bad rear blower motor, or resistor? theres a lot under the truck that could make noise, have a repair shop check it and make repairs.

The fan clutch isnt engaged at all times, therefore it may be normal to hold it in place (not recommended). On these trailblazer's 4.2L engine the fan clutch is electronically controlled. Usually when this vehicle's fan clutch malfunctions, there is a random ticking noise while idling or at a stop, also the "service engine soon" may turn on. As for the the fan speed problem, this may be a faulty blower resistor malf (typical) or climate control unit may be faulty. Hopefully this helps!!

it sounds like your battery is dead charge it and try again if the starter still clicks it means it is sticking get someone to turn the key while you hit the starter body with the handle of a hammer which will free it of

you have a short to power which will cause it to stay on constantly check your blower motor resistor pack to ensure that it is working and check the wires going to the blower to make sure you have a power and a ground

sounds like it could be your intake manifold gasket

Common issue on teh 03-06 Trailblazer instrument clusters, it's caused by failing stepper motors on the cluster's circuit board. It is fixable, check out this page for more on how to get it fixed - Trailblazer oil gauge broken

you have a trouble code stored. This means the pcm has detected a problem somewhere