Several problems (noise, error message)

[polyshin]

My car is Infiniti G35 2004 (AT).I got a couple of problem. I have no idea how can I explain this to people.1. Noise from engine(?) When I start engine in the morning, hiss noise comes from engine room. Not always... but, it started a week ago. When I drive for a while, it disappear, but it took longer time today. I suspect the belt tensioner... Am I right?2. Noise from under the car Whenever I start engine and move my car, weird noise... like old shock absorber or changing trasmission ... comes from under the car. But, just one time... after this noise right after I start driving, it disappears and never comes agian... even when I drive over hump. It comes agine when I restart and drive again...3. Tire pressure error message It's OK in the city. But, when I drive highway and speed up more than 60~70mile/hr. Tire pressure error signal appears on my dashboard and it disappears if I restart engine... and comes again after driving highway in ten minutes.

I have no idea... how can I explain these problems at customer center of Nissan.

Help me!!!!!!!!!!!

[centralcoaster33]

Have you looked around under the car and at the brake system for loose stuff? You might have a friend start it while your under the hood to see if you can't locate the source of this hiss. Do you have an automatic? Maybe your torque converter has something wrong with it that only occurs when cold? Another thought is something with the drive train, spinning parts, based on your description, but I don't know where (diff, drive shaft, transmission, bellhousing area... Have you had any work done to it? I'm obviously just guessing here. If it was my car, ABS and tire pressure monitors would be removed and dissabled. As far as describing issues to Infinity, sounds like you just need a 10-15 minute test drive with the mechanic and be sure to hop on the freeway and you'll trigger all your issues.

[qship96]

#2 sounds like ABS doing its normal self-test-if so,it is not a problem at all

[96Qowner]

#2 sounds like ABS doing its normal self-test-if so,it is not a problem at all

I agree - a sort of a clunk sound - happens in the first foot or so of driving. Normal.

3.) Just tell 'em that. One or more tires aren't at the right inflation.

1.) Hiss? That's usually the sound a loose vacuum line might make.