front end knocking and wobbly steering problem

I have a problem with my 89 celica, but the mechanic cant find a single thing wrong with it other than the power steering pump is extremly noisy, but is apparently not leaking.
Its got this horrible loud knocking/banging noise coming from the front end which is accompanied with shaky/wobbly steering that pulls to the left.

Problem is...after paying to have the thing transported to the mechanic on a tray truck cuz i was too scared to drive it...the damn thing decided to drive perfectly for the mechanic and made me feel like a stupid fool!
So, he takes at look underneath and cant find anything wrong. Is there anyone who could possibly shed some light on my problem?
Could it be a power steering problem? The mechanic says its not leaking yet, but i have topped it up several times cus its been almost empty. Is my mechanic a complete incompetant idiot?
Steering is as noisy as buggery...and the car doesnt seem to have any other major probs...oh..and apparently the cv joints are fine...so its not that.
I'm at a loss...the mechanics at a loss and i'm too scared to drive it.

Any ideas? Anyone? I would really appreciate any suggestions.

Just like a doctor, get a second opinion.
A good mechanic should be able to find a front end problem.
If it happened to you, there is an issue that needs to be addressed.
I would take it to a front end alignment shop and have tham inspect it.
thats all they work on, well not all of them. You get my point.
That type of problem could be a number of things.
tie rods, ball joints strut or even a tire. unfortunatlly the car is not in front of us so it makes it more difficulte to (guess) the problem.
I would get that second opinion from a profesonial front end tech.
Alot of front end places give free estamats as well.

Thanks for your advice...unfortunatly I still had no luck. I took it to a front end specialist who inspected it and just like my mechanic, found nothing wrong with it at all.
Its very discouraging because the problem has since dissapeared and now everyone thinks i'm dillusional.
But, honestly...cars dont just make banging noises in the front end for no good reason do they?
Is there anything else that may cause similar symptoms thats not an obvious choice? Perhaps something thats a one or two time thing and then not ever occur again? This is what my husband thinks it is. The mechanic thinks it may have had some debri or something caught under the axel or something...I dunno...all i know is that it was scary and i dont want to go through it again if possible. The only other thing thats worn out on the car is the power steering pump...could that be a possibility? Would low posersteering fluid cause it to bang like that?
Sorry for all the questions...everyone else just looks at me like i'm nuts.

I know this is off the wall; but was the air pressure in the tires (all 4) checked? I cant believe a front end man would tell you it is normal for a car to pull to the left.
Has it done it sence? how much have you driven it sence?

is your motor mount loosed? if not.. and if everything looks tight without anything being loosed or broken around your engine, i'm suggesting you should look inside the motor, it could be a loosed piston. if it's making a knocking sound from the engine but you can't seem to find anything wrong, it could be loosed mounting or something inside the motor is broken. you can also check your MOTOR BRACKET, sometimes it can be loosed causing wabbling.

Thanks for that....I'll have another talk with the mechanic.
The problem is...its been a week since it happenned and now it seems fine..no noise or wobbly steering. It has happenned to me twice and there was a period of 4 weeks inbetween where it was fine....so I dunno, it makes it really hard for the mechanic when he cant witness the problem.

In the meantime...i'm frightened to drive it. I guess i'll just have to, and hope that whatever breaks is not going to be dangerous and cause an accident.

It could be something broken in the motor thats not visible. I will have to wait till it gets worse and then deal with it.
I mean..the car has done 350,000 kms so stuff is wearing out...it cant be helped.

Thanks for your help guys....I appreciate it.