The people here are honestly trying to help you and if you read through the posts -- particularly those by B.C. and Foster you will compile a list of just about everything that can cause this problem. First thing to check (because it's pretty easy) is the charge state of the battery. There's also another good reason to check this. A poorly charged battery can cause the EXACT symptoms you are describing (clicking solenoid but no crank. If you'd like an explanation of what that means, ask. It's not too hard to understand or explain and many here can do it. It's only a mystery to you becuse you have never been exposed to it before which is not a fault with either you or the people trying to help you here).

Your mechanic has probably already done this (checked the battery and charging sytem) but maybe not. If he has replaced items necessary for the car to run, but not necessary to get the engine to turn over with the starter, then there is a real good chance that he misunderstands your description of the problem. It can be hard because people who are familiar with cars and working on them develop a sort of jargon to describe things (you see it here) and can become frustrated when talking to someone who isn't familiar with the shorthand lingo. Same thing happens to you when you try to explain poetry to your mechanic, I'll bet.

If it's not the battery or charging system, like Fostor says, the very likely culprit is the starter solenoid. Usually, this gets changed out with the starter, but it's not necessarily absolutely necessary to do this. Your mechanic could have put the solenoid that he thought was good onto the replacement starter. Flakey starter solenoids can also cause the EXACT symptom you are describing. I know this to be true from personal experience with Bosch starters.

Then, count down Foster's cold ones because they are the other things that can cause the EXACT symptoms you are seeing. Basically what Don has done is list the items which can cause a good battery to not be able to supply good and proper voltage (or supply adequate current depending on your perspective) to the starter motor. Any of these things can be intermittant like you are seeing. Also, a good mechanic knows that these things can cause the problem but even the best mechanic can overlook "the problem" from time to time.

Fortunately, like everyone here says, this is not rocket science and should not be outrageously expensive to fix. You've got a starter with solenoid, a battery and charging system, an ignition switching mechanism, and some big wires connecting it all together. A limited number of causes all easily examinable -- no black boxes or computer chips.

Finally, you seem to feel that the folks here have been a touch rude. I've only been reading this board for a short time because I have only had my Volvo fetish for a short time, but I must say that I have never encountered such a resource -- such a wealth of information freely and accurately dispensed by such a great bunch of people. Just be a little patient and remember that when someone on the internet seems to be getting "short" with you chances are about 1000 to 1 that it is not intentional. Don't misinterpret blunt but accurate advice with rudeness -- they're not the same thing. (sorry if that seems rude).

Good luck with your problem. Perhaps you can have a talk with your mechanic about the suggestions here and he can explain why they are or are not applicable to you.

Harold