thanks for your advice guys..

I didnt install the spark plugs myself...

And I have no idea what gapping is... can someone explain what regapping a spark plug is or involves? I can take it back to the private service garage and I can get them to do it...

I have also pinpointed the problem to occur mainly with the A/C activated...without the A/C on the car behaves better....hmmmm

 

Well the a/c is ALWAYS going to have an effect on vehicle performance, especially a low-torque 4 cyl at low engine speed. I know you're not an idiot but are you absolutely SURE you're not just being paranoid and the car always did it with the a/c on and you didn't pay attention? It's natural to always be more observant after getting your car worked on. To be honest, it doesn't really sound like something may be wrong... When you turn your steering wheel to full lock, you are putting serious strain on the power steering pump, so it tries to pump more to assist the steering, and since the pump is powered by the motor, this drains the motor of more power, of which there is very little at idle, which would possibly cause jerking. Same for the a/c at idle just rolling forward, the a/c is a drain on the engine as well, and there isn't a lot of power at idle to begin with. If your plugs were mis-gapped, the problem should be more consistant, and during acceleration. You can have it checked if you like, but I don't think there's really something wrong with the car. Seek as many opinions as you can though, as I am human and can be wrong.

As for the tire, there are little rubber ***** or needles all over the tire, as well as the deep, new tread. New tires will make a humming noise for a little while until those needles are gone and the tread is a little worn. Should be nothing to worry about, just don't drive too hard on brand new tires as they can be a little slippery.

Here is an explanation of gapping(don't mind the horrible diagram):

Gapping involves changing the space between the center electrode (the piece of metal surrounded by porcelain in the center of the threaded part of the plug) and the ground (small curved piece of metal that goes from the threads to the center of the electrode) using a spark plug gapper, of which there are several variants, which basically adjusts the strength of the spark and the time it takes for the spark to jump from electrode to ground, as well as the energy required to jump the gap. The manufacturer offers the specifications in your owners manual and usually on a sticker under the hood. Refer to my ghastly rendering below for the basic locations.

Hope this helped.

___ This would be the GROUND
/ This would be the GAP (measured in thousandths of an inch i.e .020")
/ _|_ This would be the ELECTRODE
|__| |__|
|_______| Threads
|_______| Threads
|_______| More threads
/________\
|__|____|_ | Nut shaped area for the socket
| |
\ /
\ /
\ /
| |
| | Connector
\_/

 

aww man! the diagram looked a lot better in the reply window! It took out all the spaces I used to line everything up! I hope you can still get the picture, if not, I'll actually put in a picture of a spark plug and show you. You could also go to auto zone, napa, kragen or pep boys and ask them to show you.

 

Thanks alot for your effort and time JBix. You have been really helpful.

 

You're very welcome, hope I helped.